ALBERT

Description:    Nanomaterials have emerging importance in laser desorption ionization mass spectrometry (LDI–MS) with the ultimate objective being to overcome some of the most important limitations intrinsically related to the use of conventional organic matrices in matrix-assisted (MA) LDI–MS. This review provides a critical overview of the most recent literature on the use of gold nanomaterials as non-conventional desorption ionization promoters in LDI–MS, with particular emphasis on bioanalytical applications. Old seminal papers will also be discussed to provide a timeline of the most significant achievements in the field. Future prospects and research needs are also briefly discussed. Content Type Journal Article Pages 1-23 DOI 10.1007/s00216-011-5120-2 Authors Rosa Pilolli, Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, Via Orabona, 4, 70126 Bari, Italy Francesco Palmisano, Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, Via Orabona, 4, 70126 Bari, Italy Nicola Cioffi, Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, Via Orabona, 4, 70126 Bari, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    In this work, we have characterized a diamine oxidase (DAO) from Lathyrus sativus and evaluated its use, for the first time, as biocatalytic component of an electrochemical biosensor for the determination of biogenic amines index in wine and beer samples. Firstly, DAO was electrokinetically characterized free in solution by means of a platinum electrode and then immobilized by using polyazetidine prepolimer on the surface of screen-printed electrodes constituted of two gold working electrodes. The amperometric measurements were carried out by using a flow system at a fixed potential of +600 mV vs the internal silver pseudo reference in phosphate buffer solution (0.1 mol l -1 , pH = 7.4). The analysis of wine and beer samples were performed in flow injection system using the dual channel transducer providing simultaneous detection of sample and blank signal, and the resulting signal (after subtraction of the blank signal) was referred to that of putrescine. The results were compared with those obtained using a modified reference method based on gas chromatography-mass spectrometry analysis on the same samples. The results obtained in the analysis of Italian wines shows the better suitability of DAO-based biosensor in the determination of the biogenic amines (BAs) index expressed as putrescine equivalent in both red and white wines, being less efficient in beer samples where it underestimates by about 50% the BAs content. Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5131-z Authors Massimo Di Fusco, Department of Chemistry and Drugs Technologies, University of Rome “La Sapienza”, Piazzale A. Moro, 5, 00185 Rome, Italy Rodolfo Federico, Department of Biology, University ‘Roma Tre’, Viale Marconi, 446, 00146 Rome, Italy Alberto Boffi, Department of Biochemical Sciences, University of Rome “La Sapienza”, Piazzale A. Moro, 5, 00185 Rome, Italy Alberto Macone, Department of Biochemical Sciences, University of Rome “La Sapienza”, Piazzale A. Moro, 5, 00185 Rome, Italy Gabriele Favero, Department of Chemistry and Drugs Technologies, University of Rome “La Sapienza”, Piazzale A. Moro, 5, 00185 Rome, Italy Franco Mazzei, Department of Chemistry and Drugs Technologies, University of Rome “La Sapienza”, Piazzale A. Moro, 5, 00185 Rome, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: ANAKON 2011 – German thoroughness meets Swiss precision Content Type Journal Article Pages 1-2 DOI 10.1007/s00216-011-5096-y Authors Oliver Bleher, Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany Melanie Ewald, Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany Felix Kolarov, Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany A. Katrin Krieg, Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany Alexander F. Le Blanc, Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany Sabrina Rau, Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    This paper describes a novel method of sample preparation for the determination of trace concentrations of polycyclic aromatic hydrocarbons (PAHs) in high-boiling petroleum products. Limits of quantitation of the investigated PAHs in materials of this type range from tens of nanograms per kilogram to 〈20 μg/kg. The studies revealed that in order to separate most of interferences from the analytes without a significant loss of PAHs, it is necessary to use size exclusion chromatography as the first step of sample preparation, followed by adsorption using normal-phase liquid chromatography. The use of orthogonal separation procedure described in the paper allows the isolation of only a group of unsubstituted and substituted aromatic hydrocarbons with a specific range of molar mass. The lower the required limit of quantitation of PAHs, the larger is the scale of preparative liquid chromatography in both steps of sample preparation needed. The use of internal standard allows quantitative results to be corrected for the degree of recovery of PAHs during the sample preparation step. Final determination can be carried out using HPLC-FLD, GC-MS, or HPLC-UV–VIS/DAD. The last technique provides a degree of identification through the acquired UV–VIS spectra. Figure  Chromatograms obtained using UV-DAD detection with wavelength programming (A) and fluorimetric detection (B) for the separation of 18 PAH standards ((A) and (B)) and the fraction containing PAHs from road asphalt 50/70 prepared according to the procedure described in this work (C) . Peak designation: 1 naphthalene, 2 acenaphthylene, 3 acenaphthene, 4 fluorene, 5 phenanthrene, 6 anthracene, 7 fluoranthene, 8 pyrene, 9 benzo[a]anthracene, 10 chrysene, 11 benzo[b]fluoranthene, 12 benzo[k]fluoranthene, 13 benzo[a]pyrene, 14 dibenzo[a,h]anthracene, 15 indeno[1,2,3-cd]pyrene, 16 benzo[ghi]perylene, 17 benzo[j]fluoranthene, 18 benzo[e]pyrene,19 highly polar components of road asphalt 50/70 eluted during backflush. BF backflush point Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5134-9 Authors Ewelina Gilgenast, Chemical Faculty, Department of Chemical and Process Engineering, Gdansk University of Technology, Narutowicza St. 11/12, 80-233 Gdansk, Poland Grzegorz Boczkaj, Chemical Faculty, Department of Chemical and Process Engineering, Gdansk University of Technology, Narutowicza St. 11/12, 80-233 Gdansk, Poland Andrzej Przyjazny, Chemistry & Biochemistry Department, Kettering University, 1700 West Third Avenue, Flint, MI 48504, USA Marian Kamiński, Chemical Faculty, Department of Chemical and Process Engineering, Gdansk University of Technology, Narutowicza St. 11/12, 80-233 Gdansk, Poland Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Here, we describe a rapid and efficient screening method using surface plasmon resonance (SPR) and saturation transfer difference–nuclear magnetic resonance (STD-NMR) spectroscopy to yield information regarding the residues involved in nucleotide binding to amino acid-coated supports. The aim of this work was to explore the use of these spectroscopic techniques to study amino acid–nucleotide interactions in order to improve the binding specificity of the amino acid ligands used to purify plasmid DNA. For SPR, we present a strategy that immobilizes arginine and lysine on a surface as model supports, and we analyze binding responses when synthetic homo-deoxyoligonucleotides are injected over the amino acid surface. The binding responses are detectable and reproducible despite the small size of the immobilized amino acids. Using STD-NMR, we performed epitope mapping of homo-deoxyoligonucleotides bound to l -arginine–bisoxyran–Sepharose and l -lysine–Sepharose supports. Polynucleotide binding preferences differed; for example, polyC interacted preferentially through its backbone with the two supports, whereas polyT bound the supports through its thymine moiety. STD-NMR combined with SPR measurements was successfully used to screen amino acid–nucleotide interactions and determine the binding affinities of the complexes. Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5124-y Authors Carla Cruz, CICS-UBI–Centro de Investigação em Ciências da Saúde, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal Eurico J. Cabrita, REQUIMTE, CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova Lisboa, 2829-516 Caparica, Portugal João A. Queiroz, CICS-UBI–Centro de Investigação em Ciências da Saúde, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    In this work, an optimization study was conducted to investigate the performance of a custom-designed miniaturized dielectric barrier discharge (DBD) microplasma chip to be utilized as a radiation source for mercury determination in water samples. The experimental work was implemented by using experimental design, and the results were assessed by applying statistical techniques. The proposed DBD chip was designed and fabricated in a simple way by using a few microscope glass slides aligned together and held by a Perspex chip holder, which proved useful for miniaturization purposes. Argon gas at 75–180 mL/min was used in the experiments as a discharge gas, while AC power in the range 75–175 W at 38 kHz was supplied to the load from a custom-made power source. A UV-visible spectrometer was used, and the spectroscopic parameters were optimized thoroughly and applied in the later analysis. Plasma characteristics were determined theoretically by analysing the recorded spectroscopic data. The estimated electron temperature ( T e  = 0.849 eV) was found to be higher than the excitation temperature ( T exc  = 0.55 eV) and the rotational temperature ( T rot  = 0.064 eV), which indicates non-thermal plasma is generated in the proposed chip. Mercury cold vapour generation experiments were conducted according to experimental plan by examining four parameters (HCl and SnCl 2 concentrations, argon flow rate, and the applied power) and considering the recorded intensity for the mercury line (253.65 nm) as the objective function. Furthermore, an optimization technique and statistical approaches were applied to investigate the individual and interaction effects of the tested parameters on the system performance. The calculated analytical figures of merit (LOD = 2.8 μg/L and RSD = 3.5%) indicates a reasonable precision system to be adopted as a basis for a miniaturized portable device for mercury detection in water samples. Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5118-9 Authors Wameath S. Abdul-Majeed, Department of Chemical and Biological Engineering, The University of Sheffield, Newcastle Street, Sheffield, S1 3JD UK Jaime H. Lozano Parada, Department of Chemical and Biological Engineering, The University of Sheffield, Newcastle Street, Sheffield, S1 3JD UK William B. Zimmerman, Department of Chemical and Biological Engineering, The University of Sheffield, Newcastle Street, Sheffield, S1 3JD UK Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    The development of a simple and rapid high-performance liquid chromatography (HPLC) method for the determination of the new antiepileptic drug rufinamide (RFN) in human plasma and saliva is reported. Samples (250 μl) are alkalinized with ammonium hydroxide (pH 9.25) and extracted with dichloromethane using metoclopramide as internal standard. Separation is achieved with a Spherisorb silica column (250 × 4.6 mm i.d., 5 μm) at 30 °C using as mobile phase a solution of methanol/dichloromethane/n-hexane 10/25/65 (vol/vol/vol) mixed with 6 ml ammonium hydroxide. The instrument used was a Shimadzu LC-10Av chromatograph and flow rate was 1.5 ml min -1 , with a LaChrom L-7400 UV detector set at 230 nm. Calibration curves are linear [ r 2  = 0.998 ± 0.002 for plasma ( n  = 10) and r 2  = 0.999 ± 0.001 for saliva ( n  = 9)] over the range of 0.25–20.0 μg ml -1 , with a limit of quantification at 0.25 μg ml -1 . Precision and accuracy are within current acceptability standards. The assay is suitable for pharmacokinetic studies in humans and for therapeutic drug monitoring. Content Type Journal Article Pages 1-9 DOI 10.1007/s00216-011-5126-9 Authors Iolanda Mazzucchelli, Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy Manuela Rapetti, Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy Cinzia Fattore, Clinical Trial Center, IRCCS National Neurological Institute C. Mondino Foundation, 27100 Pavia, Italy Valentina Franco, Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy Giuliana Gatti, Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy Emilio Perucca, Clinical Pharmacology Unit, Department of Internal Medicine and Therapeutics, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Although a DNA-immobilized packed-column (DNA-packed column), which relies on sequence-dependent interactions of target DNA or mRNA (in the mobile phase) with DNA probes (on the silica particle) in a continuous flow process, could be considered as an alternative platform for quantitative analysis of specific DNA to DNA chip methodology, the performance in practice has not been satisfactory. In this study, we set up a more efficient quantitative analysis system based on a DNA-packed column by employing a temperature-gradient strategy and DMSO-containing mobile phase. Using a temperature-gradient strategy based on T m values of probe/target DNA hybridizations and DMSO (5%)-containing mobile phase, we succeeded in the quantitative analysis of a specific complementary target distinguishable from non-complementary DNA oligomers or other similar DNA samples. In addition, two different target DNA oligomers even with similar T m values were separated and detected quantitatively by using a packed column carrying two different DNA probes. Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5129-6 Authors Seung Pil Pack, Department of Biotechnology and Bioinformatics, Korea University, Jochiwon, Chungnam 339-700, South Korea Tae-Hwe Heo, College of Pharmacy, The Catholic University of Korea, Bucheon, 420-743 South Korea Kamakshaiah Charyulu Devarayapalli, Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan Keisuke Makino, Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Breath analysis could offer a non-invasive means of intravenous drug monitoring if robust correlations between drug concentrations in breath and blood can be established. In this study, propofol blood and breath concentrations were determined in an animal model under varying physiological conditions. Propofol concentrations in breath were determined by means of two independently calibrated analytical methods: continuous, real-time proton transfer reaction mass spectrometry (PTR-MS) and discontinuous solid-phase micro-extraction coupled with gas chromatography mass spectrometry (SPME-GC-MS). Blood concentrations were determined by means of SPME-GC-MS. Effects of changes in pulmonary blood flow resulting in a decreased cardiac output (CO) and effects of dobutamine administration resulting in an increased CO on propofol breath concentrations and on the correlation between propofol blood and breath concentrations were investigated in seven acutely instrumented pigs. Discontinuous propofol determination in breath by means of alveolar sampling and SPME-GC-MS showed good agreement ( R 2  = 0.959) with continuous alveolar real-time measurement by means of PTR-MS. In all investigated animals, increasing cardiac output led to a deterioration of the relationship between breath and blood propofol concentrations ( R 2  = 0.783 for gas chromatography-mass spectrometry and R 2  = 0.795 for PTR-MS). Decreasing pulmonary blood flow and cardiac output through banding of the pulmonary artery did not significantly affect the relationship between propofol breath and blood concentrations ( R 2  〉 0.90). Estimation of propofol blood concentrations from exhaled alveolar concentrations seems possible by means of different analytical methods even when cardiac output is decreased. Increases in cardiac output preclude prediction of blood propofol concentration from exhaled concentrations. Figure  Experimental setup for simultaneous real-time (PTR-MS) and discontinuous (SPME-GC-MS) drug determination in the breath of acutely instrumented pigs ( A ). In order to assess the influence of hemodynamic variables pulmonary artery blood flow was determined by means of Doppler-measurement ( B ). Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5099-8 Authors Svend Kamysek, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Patricia Fuchs, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Henny Schwoebel, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Jan P. Roesner, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Sabine Kischkel, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Kathi Wolter, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Christian Loeseken, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Jochen K. Schubert, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Wolfram Miekisch, Department of Anesthesiology and Intensive Care, University of Rostock, Schillingallee 35, 18057 Rostock, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Predicting the amount of time that a petroleum mixture has been exposed to weathering effects has applications in areas of environmental and other forensic investigations, such as aiding in determining the cause and intent of a fire. Historically, research on the evaporation rates of hydrocarbon mixtures has focused on forensic oil spill identification and predicting if a fresh sample could be weathered to give an observed composition in an aged sample. Relatively little attention has focused on approaching the problem from the other direction: estimating exposure time based on the observed composition of a weathered sample at a given time and assuming a prior composition. Here, we build upon our previous research into the weathering of model mixtures by extending our work to gasoline. Samples of gasoline with varying octane ratings and from several vendors were weathered under controlled conditions and their composition monitored over time by two-dimensional gas chromatography (GC × GC). A variety of chemometric models were explored, including partial least squares (PLS), nonlinear PLS (PolyPLS) and locally weighted regression (LWR). A hierarchical application of multivariate techniques was able to predict the time for which a sample had been exposed to evaporative weathering. Partial least squares discriminant analysis could predict whether a sample was relatively fresh (〈12 h exposure time) or highly weathered (〉20 h exposure time). Subsequent regression models for these classes were evaluated for accuracy using the root mean square error of prediction. LWR was the most successful, whereby fresh and highly weathered samples were predicted to within 30 min and 5 h of exposure, respectively. Content Type Journal Article Pages 1-9 DOI 10.1007/s00216-011-5130-0 Authors Brianne M. Zorzetti, Department of Chemistry, University of Alberta, Edmonton, AB T6G 2 G2, Canada James J. Harynuk, Department of Chemistry, University of Alberta, Edmonton, AB T6G 2 G2, Canada Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Vibrational spectroscopy techniques can be applied to identify a susceptibility-to-adenocarcinoma biochemical signature. A sevenfold difference in incidence of prostate adenocarcinoma (CaP) remains apparent amongst populations of low- (e.g. India) compared with high-risk (e.g. UK) regions, with migrant studies implicating environmental and/or lifestyle/dietary causative factors. This study set out to determine the biospectroscopy-derived spectral differences between risk-associated cohorts to CaP. Benign prostate tissues were obtained using transurethral resection from high-risk ( n  = 11, UK) and low-risk ( n  = 14, India) cohorts. Samples were analysed using attenuated total reflection Fourier-transform infrared (FTIR) spectroscopy, FTIR microspectroscopy and Raman microspectroscopy. Spectra were subsequently processed within the biochemical cell region (1,800 −1 –500 cm –1 ) employing principal component analysis (PCA) and linear discriminant analysis (LDA) to determine whether wavenumber–absorbance/intensity relationships might reveal biochemical differences associated with region-specific susceptibility to CaP. PCA-LDA scores and corresponding cluster vector plots identified pivotal segregating biomarkers as 1,582 cm −1 (Amide I/II trough); 1,551 cm −1 (Amide II); 1,667 cm −1 (Amide I); 1,080 cm −1 (DNA/RNA); 1,541 cm −1 (Amide II); 1,468 cm −1 (protein); 1,232 cm −1 (DNA); 1,003 cm −1 (phenylalanine); 1,632 cm −1 [right-hand side (RHS) Amide I] for glandular epithelium ( P  〈 0.0001) and 1,663 cm −1 (Amide I); 1,624 cm −1 (RHS Amide I); 1,126 cm −1 (RNA); 1,761, 1,782, 1,497 cm −1 (RHS Amide II); 1,003 cm −1 (phenylalanine); and 1,624 cm −1 (RHS Amide I) for adjacent stroma ( P  〈 0.0001). Primarily protein secondary structure variations were biomolecular markers responsible for cohort segregation with DNA alterations exclusively located in the glandular epithelial layers. These biochemical differences may lend vital insights into the aetiology of CaP. Figure  The first study to apply biospectroscopy techniques to identify the underlying differences in the aetiology of prostate cancer between low- (India) compared to high-risk (UK) cohorts Content Type Journal Article Pages 1-14 DOI 10.1007/s00216-011-5123-z Authors Imran I. Patel, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Júlio Trevisan, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Paras B. Singh, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Caroline M. Nicholson, Lancashire Teaching Hospitals NHS Trust, Fulwood, Preston, PR2 9HT UK R. K. Gopala Krishnan, Workhardt Hospital, Kolkata, 700020 India Shyam S. Matanhelia, Lancashire Teaching Hospitals NHS Trust, Fulwood, Preston, PR2 9HT UK Francis L. Martin, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Glycosylation is one of the most common yet diverse post-translational modifications. Information on glycan heterogeneity and glycosite occupancy is increasingly recognized as crucial to understanding glycoprotein structure and function. Yet, no approach currently exists with which to holistically consider both the proteomic and glycomic aspects of a system. Here, we developed a novel method of comprehensive glycosite profiling using nanoflow liquid chromatography/mass spectrometry (nano-LC/MS) that shows glycan isomer-specific differentiation on specific sites. Glycoproteins were digested by controlled non-specific proteolysis in order to produce informative glycopeptides. High-resolution, isomer-sensitive chromatographic separation of the glycopeptides was achieved using microfluidic chip-based capillaries packed with graphitized carbon. Integrated LC/MS/MS not only confirmed glycopeptide composition but also differentiated glycan and peptide isomers and yielded structural information on both the glycan and peptide moieties. Our analysis identified at least 13 distinct glycans (including isomers) corresponding to five compositions at the single N -glycosylation site on bovine ribonuclease B, 59 distinct glycans at five N -glycosylation sites on bovine lactoferrin, 13 distinct glycans at one N -glycosylation site on four subclasses of human immunoglobulin G, and 20 distinct glycans at five O -glycosylation sites on bovine κ-casein. Porous graphitized carbon provided effective separation of glycopeptide isomers. The integration of nano-LC with MS and MS/MS of non-specifically cleaved glycopeptides allows quantitative, isomer-sensitive, and site-specific glycoprotein analysis. Figure  Overlaid chromatograms and associated structural assignments of glycopeptides from bovine κ-casein. Color denotes the site(s) of glycosylation from which the glycopeptide originated Content Type Journal Article Pages 1-12 DOI 10.1007/s00216-011-5109-x Authors Serenus Hua, Department of Chemistry, University of California, Davis, CA 95616, USA Charles C. Nwosu, Department of Chemistry, University of California, Davis, CA 95616, USA John S. Strum, Department of Chemistry, University of California, Davis, CA 95616, USA Richard R. Seipert, Department of Chemistry, University of California, Davis, CA 95616, USA Hyun Joo An, Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 305-764 South Korea Angela M. Zivkovic, Department of Food Science and Technology, University of California, Davis, CA 95616, USA J. Bruce German, Department of Food Science and Technology, University of California, Davis, CA 95616, USA Carlito B. Lebrilla, Department of Chemistry, University of California, Davis, CA 95616, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    The American visceral leishmaniasis is an important cause of morbidity and mortality in Brazil for both humans and dogs. Attempts to make a diagnosis of this disease need to be improved, especially in endemic areas, and in the tracking and screening of asymptomatic dogs, which are their main host in urban areas. A quartz crystal microbalance immunosensor for the diagnosis of the canine visceral leishmaniasis using a recombinant antigen of Leishmania chagasi (rLci2B-NH6) was developed. The rLci2B-NH6 was tightly immobilized on a quartz crystal gold electrode by self-assembled monolayer based on short-chain length thiol. The strategy was the use of the antigen-histidine tail covalently linked to glutaraldehyde performing a Schift base which permits a major exposure of epitopes and a reduced steric hindrance. The immunosensor showed good results regarding sensitivity and reproducibility, being able to distinguish positive and negative canine serum for L. chagasi. Furthermore, the immunosensor can be reused through exposure to sodium dodecyl sulfate solution, which promotes the dissociation of antigen–antibody binding, restoring the sensor surface with immobilized biologically active antigens for further analysis. Content Type Journal Article Pages 1-9 DOI 10.1007/s00216-011-5136-7 Authors Joilson Ramos-Jesus, Laboratório de Engenharia Biomédica, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, 1235-Cidade Universitária, Recife, Pernambuco 50670-901, Brazil Kellyanne A. Carvalho, Departamento de Biointeração, Universidade Federal da Bahia, Salvador, Bahia 40110-060, Brazil Rosana A. S. Fonseca, Laboratório de Engenharia Biomédica, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, 1235-Cidade Universitária, Recife, Pernambuco 50670-901, Brazil Geraldo G. S. Oliveira, Centro de Pesquisa Gonçalo Muniz, Fundação Oswaldo Cruz, Bahia 40296-710, Brazil Stella M. Barrouin Melo, Departamento de Patologia e Clínicas, Universidade Federal da Bahia, Salvador, Bahia 40110-060, Brazil Neuza M. Alcântara-Neves, Departamento de Biointeração, Universidade Federal da Bahia, Salvador, Bahia 40110-060, Brazil Rosa F. Dutra, Laboratório de Engenharia Biomédica, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, 1235-Cidade Universitária, Recife, Pernambuco 50670-901, Brazil Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: We use dissolved silicon together with its “geochemical twin” germanium for the first time as a hydrologic tracer to study water delivery to the stream during storm events in the Rio Icacos watershed, Puerto Rico. Ge and Si were measured on base flow, stormflow, springwater, and soil water samples. Compositions of all of these waters appear to reflect varying contributions from three components, which we attribute to solutes released from bedrock weathering (groundwater), from short-term soil-water interaction (quick soil water), and longer-term soil-water interaction (matrix soil water). Base flow stream waters have high Si and moderate Ge (Ge/Si ratio ∼0.29 μmol/mol), consistent with a predominantly bedrock weathering source as indicated by their similarity with water sampled from springs emerging from the saprolite-bedrock boundary on a hillslope landslide scar. During storm events there is a shift toward more dilute compositions (but higher Ge/Si ratios) similar to those measured on water samples from temporary depression storage and overland flow (quick soil water). Geochemical mass balance shows that 80%–90% of the stream chemistry can be explained by mixing groundwater with this quick soil water composition, which we infer to reflect new water traveling as shallow throughflow. Stream water δ18O values decrease to more negative values typical of precipitation supporting rapid delivery of rainwater to the stream channel during stormflow. The third component, with a Ge-rich composition characteristic of soil matrix water sampled by tension lysimeters, is required to explain higher stream water Ge/Si ratios measured during hydrograph recession. We infer from this an additional, slower, and less dominant pathway for delivery of soil water to the stream channel.

Description: We present a predictive, multiscale modeling framework for chemotaxis in porous media. This model results from volume averaging the governing equations for bacterial transport at the microscale and is expressed in terms of effective medium coefficients that are predicted from the solution of the associated closure problems. As a result, the averaged chemotactic velocity is an explicit function of the attractant concentration field and diffusivity, rather than an empirical effective chemotactic sensitivity coefficient. The model was validated by comparing the transverse bacterial concentration profiles with experimental measurements for Escherichia coli HCB1 in a T-sensor. The averaged chemotactic velocity predicted by the model was found to be within the range of values reported in the literature. Reasonable agreement (approximately 10% mean absolute error) between theory and experiments was found for several flow rates. In order to assess the potential for decreasing the computational demands of the model, the macroscale domain was divided into subdomains for the coupling of bacterial transport to that of the attractant. Sensitivity analysis was performed regarding the number of subdomains chosen, and the results indicate that bacterial transport (as measured by concentration profiles) was not highly affected by this choice. Overall, these results suggest that the predictive, multiscale modeling framework is reliable for modeling chemotaxis in porous media when chemotactic transport is significant compared to convective transport.

Description:    Residues from medicine containers in the collections of the British Museum have been investigated as part of a wider programme of scientific work on Roman surgical instruments. The cylindrical bronze containers are often described as instrument cases, but some contain materia medica , ranging from extensive extant remains of ancient preparations to possible minor deposits on the interior surfaces of the containers. Samples from seven residues have been analysed by gas chromatography–mass spectrometry (GC-MS) to identify lipid, resin and carbohydrate components and by X-ray fluorescence and Raman spectroscopy to characterise inorganic materials. The results have provided evidence for ointments and powders or pills consistent with a medical purpose. The ingredients identified include beeswax, fat, conifer resin and gum-derived sugars, plus elemental carbon and lead and zinc salts. Particularly significant were the varied compositions of residues from four sections of a multi-compartment container. In one of these compartments, the beeswax seems to have been prepared as the ‘Punic wax’ described by Pliny. Experimental preparation of Punic wax following Pliny’s method was undertaken in the laboratory and the product analysed to compare with the ointment residues. This paper discusses the GC-MS results of both the experimental material and the archaeological residues and their significance for the interpretation of the past intended applications of the medicines and the use of the containers. Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5160-7 Authors R. J. Stacey, Department of Conservation and Scientific Research, The British Museum, Great Russell Street, London, WC1B 3DG UK Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Sensitive and robust bioassays for glucocorticoids are very useful for the pharmaceutical industry, environmental scientists and veterinary control. Here, a recombinant yeast cell was constructed that expresses the human glucocorticoid receptor alpha and a green fluorescent reporter protein in response to glucocorticoids. Both the receptor construct and the reporter construct were stably integrated into the yeast genome. The correct and specific functioning of this yeast glucocorticoid bioassay was studied by exposures to cortisol and other related compounds and critically compared to a GR-CALUX bioassay based on a human bone cell. Although less sensitive, the new yeast glucocorticoid bioassay showed sensitivity towards all (gluco)corticoids tested, with the following order in relative potencies: budesonide 〉〉 corticosterone 〉 dexamethasone 〉 cortisol = betamethasone 〉 prednisolone 〉 aldosterone. Hormone representatives for other hormone nuclear receptors, like 17β-estradiol for the oestrogen receptor, 5α-dihydrotestosterone for the androgen receptor and progesterone for the progesterone receptor, showed no clear agonistic responses, whilst some polychlorinated biphenyls were clearly able to interfere with the GR activity. Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5162-5 Authors Toine F. H. Bovee, RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, the Netherlands Richard J. R. Helsdingen, RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, the Netherlands Astrid R. M. Hamers, RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, the Netherlands Bram A. Brouwer, BioDetection Systems B.V. (BDS), Kruislaan 406, 1098 SM Amsterdam, the Netherlands Michel W. F. Nielen, RIKILT-Institute of Food Safety, Wageningen University and Research Centre, Akkermaalsbos 2, 6708 WB Wageningen, the Netherlands Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Water temperature determines the spatial distribution of fish species, including cold-water fish such as trout, and is driven by the balance of the heat flux across the water surface and the heat flux across the sediment surface. In this study, a modified equilibrium temperature model was developed for cold-water streams that includes the effect of groundwater inflow. The modified equilibrium temperature model gives estimates of daily average stream temperature based on climate conditions, riparian shading, stream width, and groundwater input rate and temperature. For a small tributary stream with relatively uniform riparian shading, the modified equilibrium temperature was found to be a good predictor of daily average stream temperature, with a root-mean-square errors (RMSE) of 1.2°C. The modified equilibrium temperature model also gave good estimates (1.4°C RMSE) of daily average stream temperature for a larger stream when riparian shading was averaged over sufficiently long distances. A sensitivity analysis using the modified equilibrium temperature model confirmed that water temperature in cold-water streams varies strongly with riparian shading, stream width, and both groundwater inflow rate and temperature. These groundwater parameters therefore need to be taken into account when climate change impacts on stream temperature are projected. The stream temperature model developed in this study is a useful tool to characterize temperature conditions in cold-water streams with different levels of riparian shading and groundwater inputs and to assess the impact of future land use and climate change on temperature in these streams.

Description: Perfect or even mediocre weather predictions over a long period are almost impossible because of the ultimate growth of a small initial error into a significant one. Even though the sensitivity of initial conditions limits the predictability in chaotic systems, an ensemble of prediction from different possible initial conditions and also a prediction algorithm capable of resolving the fine structure of the chaotic attractor can reduce the prediction uncertainty to some extent. All of the traditional chaotic prediction methods in hydrology are based on single optimum initial condition local models which can model the sudden divergence of the trajectories with different local functions. Conceptually, global models are ineffective in modeling the highly unstable structure of the chaotic attractor. This paper focuses on an ensemble prediction approach by reconstructing the phase space using different combinations of chaotic parameters, i.e., embedding dimension and delay time to quantify the uncertainty in initial conditions. The ensemble approach is implemented through a local learning wavelet network model with a global feed-forward neural network structure for the phase space prediction of chaotic streamflow series. Quantification of uncertainties in future predictions are done by creating an ensemble of predictions with wavelet network using a range of plausible embedding dimensions and delay times. The ensemble approach is proved to be 50% more efficient than the single prediction for both local approximation and wavelet network approaches. The wavelet network approach has proved to be 30%–50% more superior to the local approximation approach. Compared to the traditional local approximation approach with single initial condition, the total predictive uncertainty in the streamflow is reduced when modeled with ensemble wavelet networks for different lead times. Localization property of wavelets, utilizing different dilation and translation parameters, helps in capturing most of the statistical properties of the observed data. The need for taking into account all plausible initial conditions and also bringing together the characteristics of both local and global approaches to model the unstable yet ordered chaotic attractor of a hydrologic series is clearly demonstrated.

Description: The focus in the search for more reliable predictions in ungauged basins (PUB) has generally been on reducing uncertainty in watershed models (mainly their parameters). More recently, however, we seem to remember that the ultimate objective is not to define the parameters of a specific model but to understand the watershed: What behavior do we expect the ungauged watershed to exhibit? And what behavior should not occur in a particular ungauged watershed? The answers to these questions actually provide additional information that can be assimilated in watershed models for uncertainty reduction in PUB. This extension to hydrologic modeling approaches provides a quantitative link between watershed modeling and statistical hydrology as well as process hydrology that has to be explored. We witness a convergence of approaches—Bayesian, set theoretic, and optimization based—toward utilizing this link. The result is an opportunity for the (quantitative) dialog between modelers, statistical hydrologists, and experimentalists. We close our discussion of this development by presenting new and exciting research questions that we now have to address.

Description: Concept development simulation with distributed, physics-based models provides a quantitative approach for investigating runoff generation processes across environmental conditions. Disparities within data sets employed to design and parameterize boundary value problems used in heuristic simulation inevitably introduce various levels of bias. The objective was to evaluate the impact of boundary value problem complexity on process representation for different runoff generation mechanisms. The comprehensive physics-based hydrologic response model InHM has been employed to generate base case simulations for four well-characterized catchments. The C3 and CB catchments are located within steep, forested environments dominated by subsurface stormflow; the TW and R5 catchments are located in gently sloping rangeland environments dominated by Dunne and Horton overland flows. Observational details are well captured within all four of the base case simulations, but the characterization of soil depth, permeability, rainfall intensity, and evapotranspiration differs for each. These differences are investigated through the conversion of each base case into a reduced case scenario, all sharing the same level of complexity. Evaluation of how individual boundary value problem characteristics impact simulated runoff generation processes is facilitated by quantitative analysis of integrated and distributed responses at high spatial and temporal resolution. Generally, the base case reduction causes moderate changes in discharge and runoff patterns, with the dominant process remaining unchanged. Moderate differences between the base and reduced cases highlight the importance of detailed field observations for parameterizing and evaluating physics-based models. Overall, similarities between the base and reduced cases indicate that the simpler boundary value problems may be useful for concept development simulation to investigate fundamental controls on the spectrum of runoff generation mechanisms.

Description: Analytical solutions are obtained for optimization formulations that minimize energy used for groundwater pumping. The formulations choose pumping rates at groundwater wells while insuring that total pumpage meets a specified demand. Such formulations might be appropriate for an urban water supply or a large−scale agricultural irrigation system. Solutions are found by applying stationarity conditions. The solutions produce simple and physically meaningful requirements on drawdowns at each well. Under certain conditions, pumping rates are optimal when the sum of the nonpumping lift and two times the drawdown at each pumping well takes a constant value across the domain. The results are examined for steady and transient conditions. The results are based on only a few assumptions on the modeled system: the response of drawdown with head is linear, and all pumping activity occurs during the same time periods. Implications of these results for well field operation are suggested.

Description: Water pricing schedules often contain significant nonlinearities, such as the increasing block tariff (IBT) structure that is abundantly applied for residential users. The IBT is frequently supported as a good tool for achieving the goals of equity, water conservation, and revenue neutrality but seldom has been grounded on efficiency justifications. In particular, existing literature on water pricing establishes that although efficient schedules will depend on demand and supply characteristics, IBT cannot usually be recommended. In this paper, we consider whether the explicit inclusion of scarcity considerations can strengthen the appeal of IBT. Results show that when both demand and costs react to climate factors, increasing marginal prices may come about as a response to a combination of water scarcity and customer heterogeneity. We derive testable conditions and then illustrate their application through an estimation of Portuguese residential water demand. We show that the recommended tariff schedule hinges crucially on the choice of functional form for demand.

Description: In situ laser diffractometers characterize the suspended particle size distribution (PSD) by measuring laser-generated light scattered off small particles over a range of small forward angles. In environments with low particulate concentrations or high ambient light conditions the ratio of natural downwelling sunlight to scattered laser light sensed by the photodetectors is high and measurements are influenced. Here, we evaluate the effect of the ambient light field intensity on measurements made with a Laser In Situ Scattering and Transmissometry (LISST) 100X type B instrument. Paired light-dark scattering distributions are recorded over a range of underwater light intensities in high-turbidity and low-turbidity water. Light measurements displayed large erroneous concentrations of particles in the smallest size bin (1.25–1.48 μm) and showed effects over the full range of the PSD. Ambient light was found to exhibit the same constant distribution over the instrument photodetectors in both water samples, although the magnitude of the response, in laser counts per unit ambient light intensity, was PSD dependent. A technique for postprocessing data to remove the influence of light is presented for moored deployment and vertical profile data collected at Lake Tahoe, California-Nevada, United States. While measurements removed of the light effect were successfully reconstructed, the technique may not be applicable to data where the PSD or the LISST orientation relative to the sun direction change rapidly or when light intensities are high enough to quench the instrument photodetectors. Ambient light was found to have negligible effects on PSD measurements in Lake Tahoe was below intensities of ∼30 W m−2.

Description: The emergence of multimodal imaging methods for real-time nanoscopy Content Type Journal Article Pages 1-2 DOI 10.1007/s00216-011-5125-x Authors Cyril Petibois, University of Bordeaux, CNRS UMR 5248 CBMN Allée de Saint-Hillaire, F33600 Pessac-Cedex, France Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Chemometric methods have critical importance for the discovery of the information/knowledge buried or concealed in high-dimensional datasets acquired from comprehensive multidimensional separations (CMDS), and for interpretation of experiments or chemical processes. In this work, employment of new developments in chemometrics making full use of the data to maximize the potential of CMDS to resolve mathematically a variety of practical problems is reviewed whilst providing the authors' point of view. During the past several years, chemometrics has been successfully applied to many areas of concern to CMDS investigation, including experimental parameter optimization, data quality improvement, identification and quantification of target chemical components, pattern recognition technique for clustering and classification, multivariate model establishment to correlate chromatographic properties and molecular descriptors. On the basis of the high-dimensionality characteristics of CMDS, some special aspects such as evaluation of orthogonality and image processing have also been included in this review. It is expected that an overview of the diverse ways in which chemometrics can aid CMDS investigations will prove valuable to interested users in this area through a comprehensive survey of previous research contributions. Chemometrics lends itself well to the powerful separation capability of CMDS. Content Type Journal Article Pages 1-14 DOI 10.1007/s00216-011-5139-4 Authors Zhong-Da Zeng, Centre for Green Chemistry, School of Chemistry, Monash University, Wellington Rd, Clayton, 3800 Australia Helmut M. Hugel, School of Applied Sciences, RMIT University, G.P.O. Box 2476, Melbourne, 3001 Australia Philip J. Marriott, Centre for Green Chemistry, School of Chemistry, Monash University, Wellington Rd, Clayton, 3800 Australia Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Chemical analysis of ancient residues of pharmaceutical or cosmetic preparations such as balms or ointments is made problematic by the high complexity of these mixtures, composed of organic and inorganic materials. Consequently, a multi-analytical approach and special caution in the interpretation of the results are necessary. In order to contribute to the improvement of analytical strategies for the characterization of complex residues and to reconstruct ancient medical practices, a replica of a pharmaceutical formulation of the seventeenth century was prepared in the laboratory according to a historically documented recipe. In a round robin exercise, a portion of the preparation was analysed as a blind sample by 11 laboratories using various analytical techniques. These included spectroscopic, chromatographic and mass spectrometric methods. None of the laboratories was able to completely reconstruct the complex formulation, but each of them gave partial positive results. The round robin exercise has demonstrated that the application of a multi-analytical approach can permit a complete and reliable reconstruction of the composition. Finally, on the basis of the results, an analytical protocol for the study of residues of ancient medical and pharmaceutical preparations has been outlined. Content Type Journal Article Pages 1-14 DOI 10.1007/s00216-011-5105-1 Authors M. P. Colombini, Dipartimento di Chimica, SCIBEC, Università di Pisa, 56126 Pisa, Italy F. Modugno, Dipartimento di Chimica, SCIBEC, Università di Pisa, 56126 Pisa, Italy M. C. Gamberini, Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy M. Rocchi, Dipartimento di Chimica, SCIBEC, Università di Pisa, 56126 Pisa, Italy C. Baraldi, Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy T. Deviese, British Museum, Department of Conservation and Scientific Research, London, WC1B 3DG UK R. J. Stacey, British Museum, Department of Conservation and Scientific Research, London, WC1B 3DG UK M. Orlandi, Dipartimento di Scienze dell’Ambiente e del Territorio, Università di Milano Bicocca, 20126 Milan, Italy F. Saliu, Dipartimento di Scienze dell’Ambiente e del Territorio, Università di Milano Bicocca, 20126 Milan, Italy C. Riedo, Dipartimentodi Chimica IFM e NIS Centro di Eccellenza, Università degli Studi di Torino, 10124 Turin, Italy O. Chiantore, Dipartimentodi Chimica IFM e NIS Centro di Eccellenza, Università degli Studi di Torino, 10124 Turin, Italy G. Sciutto, Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Microchemistry and Microscopy Art Diagnostic Laboratory (M2ADL), Università di Bologna, 40126 Bologna, Italy E. Catelli, Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Microchemistry and Microscopy Art Diagnostic Laboratory (M2ADL), Università di Bologna, 40126 Bologna, Italy L. Brambilla, Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, 20133 Milan, Italy L. Toniolo, Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, 20133 Milan, Italy C. Miliani, Istituto CNR-ISTM Perugia, 06123 Perugia, Italy P. Rocchi, Istituto CNR-ISTM Perugia, 06123 Perugia, Italy J. Bleton, LETIAM, IUT d’Orsay, 91400 Orsay, France U. Baumer, Doerner Institut, 80799 Munich, Germany P. Dietemann, Doerner Institut, 80799 Munich, Germany G. Pojana, Università Ca‘Foscari Venezia, 30123 Venetia, Italy S. Marras, Università Ca‘Foscari Venezia, 30123 Venetia, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Spatial and temporal trends in stream chemistry were investigated in a large (1600 km2) alpine watershed in the southern Rocky Mountains of Colorado to help understand mechanisms of streamflow generation. We observed linear increases of concentrations of chemical constituents in streamflow as accumulated drainage area increased along the main channel of Saguache Creek. We tested two conceptual models of streamflow generation against our stream chemistry observations. One model is essentially two-dimensional and treats streamflow generation at the large watershed scale as the aggregation of runoff responses from individual hillslopes, primarily surface and shallow subsurface flow paths. Alternatively, a fully three-dimensional conceptual model treats streamflow generation as being controlled by a distribution of large-scale groundwater flow paths as well as surface and shallow subsurface flow paths. The structure and magnitude of groundwater contributions in streamflow as a function of increasing scale provided a key distinction between these two conceptual models. End-member mixing analysis and measurements of hydraulic head gradients in streambeds were used to quantify basin-scale groundwater contributions to streamflow with increasing spatial scale in the Saguache Creek watershed. Our data show that groundwater contributions are important in streamflow generation at all scales and, more importantly, that groundwater contributions to streamflow do increase with increasing watershed scale. These results favor the three-dimensional conceptual model in which long groundwater flow paths provide a streamflow generation process at large scales that is not operative at smaller scales. This finding indicates that large watersheds may be more than simply the aggregation of hillslopes and small catchments.

Description:    Bisphenol A (BPA) is a synthetic industrial reactant used in the production of polycarbonate plastics, and genistein is a natural phytoestrogen abundant in the soybean. Current studies investigating the endocrine-disrupting effects of concomitant exposures to BPA and genistein have warranted the development of an analytical method for the simultaneous measurement of BPA and genistein, as well as their primary metabolites, bisphenol A ß- d -glucuronide (BPA gluc) and genistein 4′-ß- d -glucuronide (genistein gluc), respectively. All four analytes were extracted from rat plasma via solid phase extraction (SPE). Three SPE cartridges and four elution schemes were tested. Plasma extraction using Bond Elut Plexa cartridges with sequential addition of ethyl acetate, methanol, and acetonitrile yielded optimal average recoveries of 98.1 ± 1.8% BPA, 94.9 ± 8.0% genistein, 91.4 ± 6.1% BPA gluc, and 103 ± 6.1% genistein gluc. Identification and quantification of the four analytes were performed by a validated HPLC-MS/MS method using electrospray ionization and selective reaction monitoring. This novel analytical method should be applicable to the measurement of BPA, genistein, BPA gluc, and genistein gluc in urine, cultures, and tissue following in vivo exposures. While reports of the determination of BPA and genistein independently exist, the simultaneous optimized extraction and detection of BPA, genistein, BPA gluc, and genistein gluc have not previously been reported. Figure  BPA and genistein co-exposure scenario. BPA-laden polycarbonate plastic baby bottle filled with soymilk, a rich source of genistein, provides a classic exposure scenario to young children—a population that is particularly vulnerable to the effects of endocrine-disrupting compounds Content Type Journal Article Pages 1-8 DOI 10.1007/s00216-011-5151-8 Authors Janis L. Coughlin, Environmental and Occupational Health Sciences Institute, A Joint Institute of Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Piscataway, NJ 08854, USA Bozena Winnik, Environmental and Occupational Health Sciences Institute, A Joint Institute of Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Piscataway, NJ 08854, USA Brian Buckley, Environmental and Occupational Health Sciences Institute, A Joint Institute of Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Piscataway, NJ 08854, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Microbial biodiversity in groundwater and soil presents a unique opportunity for improving characterization and monitoring at sites with multiple contaminants, yet few computational methods use or incorporate these data because of their high dimensionality and variability. We present a systematic, nonparametric decision-making methodology to help characterize a water quality gradient in leachate-contaminated groundwater using only microbiological data for input. The data-driven methodology is based on clustering a set of molecular genetic-based microbial community profiles. Microbes were sampled from groundwater monitoring wells located within and around an aquifer contaminated with landfill leachate. We modified a self-organizing map (SOM) to weight the input variables by their relative importance and provide statistical guidance for classifying sample similarities. The methodology includes the following steps: (1) preprocessing the microbial data into a smaller number of independent variables using principal component analysis, (2) clustering the resulting principal component (PC) scores using a modified SOM capable of weighting the input PC scores by the percent variance explained by each score, and (3) using a nonparametric statistic to guide selection of appropriate groupings for management purposes. In this landfill leachate application, the weighted SOM assembles the microbial community data from monitoring wells into groupings believed to represent a gradient of site contamination that could aid in characterization and long-term monitoring decisions. Groupings based solely on microbial classifications are consistent with classifications of water quality from hydrochemical information. These microbial community profile data and improved decision-making strategy compliment traditional chemical groundwater analyses for delineating spatial zones of groundwater contamination.

Description: Legal scholars and jurists have identified several criteria (e.g., hydrology, climate, population, and historical water use) to guide equitable allocation of transboundary rivers among riparian claimants. Are these criteria used in practice, such that a quantitative pattern emerges from actual water-sharing agreements regarding factors affecting allocations? To address this, we study interstate compacts, the principal mechanism for allocating the waters of transboundary rivers within the United States. We develop a georeferenced data set and construct variables representing conditions in state-based watersheds of 14 rivers at the times of compact ratification. A state's water allocation share of a compact serves as the dependent variable, and a set of explanatory variables is derived from legal and political theories. We estimate allocation shares using both ordinary least squares (OLS) and bootstrap regressions, and we apply two alternative specifications of the factors affecting compact allocations, one with and one without political variables. Estimated coefficients on variables for land area, population, prior water use, riparian position, and Congressional committee chair are statistically significant in the OLS regressions. The preferred OLS specification, which includes political variables, provides a good fit (R2 = 0.84). We also find that OLS and bootstrap regressions have a similar ability to predict state allocation shares. We discuss how the results could be used as a reference point in negotiations over new compacts or international river treaties and as a basis to identify existing compacts with statistical outliers.

Description:    The recent use of a one-dimensional (1D) X-ray Talbot interferometer has triggered great interest in X-ray differential phase contrast imaging. As an improved version of a 1D interferometer, the development of two-dimensional (2D) grating interferometry strongly stimulated applications of grating-based imaging. In the framework of Fresnel diffraction theory, we investigated the self-image of 2D-phase gratings under partially coherent illumination. The fringe visibility of the self-image has been analyzed as a function of the spatial coherence length. From the viewpoint of self-image visibility, it is possible to find the optimal 2D grid for 2D X-ray grating interferometer imaging. Numerical simulations have been also carried out for quantitative evaluation. Results, in good agreement with theoretical analysis, indicate the spatial coherence requirements of the radiation illuminating a 2D grating interferometer. Moreover, our results can be used to optimize performances of a 2D grating interferometer and for further theoretical and experimental research on grating-based imaging systems. Content Type Journal Article Pages 1-6 DOI 10.1007/s00216-011-5146-5 Authors Xin Ge, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230026 China Zhili Wang, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230026 China Kun Gao, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230026 China Kai Zhang, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 China Youli Hong, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 China Dajiang Wang, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230026 China Zhongzhu Zhu, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 China Peiping Zhu, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 China Ziyu Wu, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230026 China Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    An ultra-performance liquid chromatography-tandem mass spectrometry method was developed, optimised and validated for the quantification of synthetic folic acid (FA), also called pteroyl- l -glutamic acid or vitamin B9 and naturally occurring 5-methyltetrahydrofolate (5-MTHF) found in folate-fortified breads. Optimised sample preparation prior to analysis involved addition of 13 C 5 labelled internal standards, treatments with α-amylase and rat serum, solid-phase extraction using aromatic-selective cartridges and ultra-filtration. Analytes were separated on a Waters ACQUITY HSS T3 column during a 6-min run and analysed by positive ion electrospray selected reaction monitoring MS/MS. Standard calibration curves for the two analytes were linear over the range of 0.018–14 μg FA/g of fresh bread ( r 2  = 0.997) and 9.3–900 ng 5-MTHF/g of fresh bread ( r 2  = 0.999). The absolute recoveries were 90% and 76% for FA and 5-MTHF, respectively. Intra-day coefficients of variation were 3% for FA and 18% for 5-MTHF. The limit of detection was 9.0 ng/g for FA and 4.3 ng/g for 5-MTHF, determined using pre-extracted tapioca starch as the blank matrix. The assay is rugged, fast, accurate and sensitive, applicable to a variety of food matrices and is capable of the detection and quantification of the naturally occurring low levels of 5-MTHF in wheat breads. The findings of this study revealed that the FA range in Australian fortified breads was 79–110 μg/100 g of fresh bread and suggest that the flour may not have the mandated FA fortification level (200–300 μg/100 g of flour), though this cannot be determined conclusively from experimental bread data alone, as variable baking losses have been documented by other authors. Figure  Chromatogram of labelled folic acid using UPLC-MS/MS Content Type Journal Article Pages 1-8 DOI 10.1007/s00216-011-5156-3 Authors Maria V. Chandra-Hioe, Food Science and Technology, School of Chemical Engineering, University of New South Wales, Sydney, 2052 Australia Martin P. Bucknall, Mark Wainwright Analytical Centre, Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, 2052 Australia Jayashree Arcot, Food Science and Technology, School of Chemical Engineering, University of New South Wales, Sydney, 2052 Australia Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Transverse mixing of solutes in steady state transport is of utmost importance for assessing mixing-controlled reactions of compounds that are continuously introduced into the subsurface. Classical spatial moments analysis fails to describe mixing because the tortuous streamlines in heterogeneous formations cause plume meandering, squeezing, and stretching, which affect transverse spatial moments even if there is no mass transfer perpendicular to the direction of flow. For transverse solute mixing, however, the decisive process is the exchange of solute mass between adjacent stream tubes. We therefore reformulate the advection-dispersion equation in streamline coordinates (i.e., in terms of the potential and the stream function values) and analyze how flux-related second central moments of plumes increase with dropping hydraulic potential. We compare the ensemble behavior of these second central moments in random two-dimensional heterogeneous flow fields with the moments in an equivalent homogeneous system, thus defining an equivalent effective transverse dispersion coefficient. Unlike transverse macrodispersion coefficients derived by traditional moment analysis, our mixing-relevant, flux-related coefficient does not increase with travel distance. We present closed-form solutions for the mean enhancement of transverse mixing by heterogeneity in two-dimensional isotropic media for linear laws of local-scale transverse dispersion. The mixing enhancement factor increases with the log conductivity variance but remains fairly low. We also evaluate the variance of our cumulative measure of transverse mixing, showing that heterogeneity causes substantial uncertainty of mixing. The analytical expressions are compared to numerical Monte Carlo simulations for various values of log conductivity variance, indicating good agreement with the analytical results at low variability. In the numerical simulations, we also consider nonlinear models of local-scale transverse dispersion.

Description: Hydrologic modelers often need to know which method of quantitative precipitation estimation (QPE) is best suited for a particular catchment. Traditionally, QPE methods are verified and benchmarked against independent rain gauge observations. However, the lack of spatial representativeness limits the value of such a procedure. Alternatively, one could drive a hydrological model with different QPE products and choose the one which best reproduces observed runoff. Unfortunately, the calibration of conceptual model parameters might conceal actual differences between the QPEs. To avoid such effects, we abandoned the idea of determining optimum parameter sets for all QPE being compared. Instead, we carry out a large number of runoff simulations, confronting each QPE with a common set of random parameters. By evaluating the goodness-of-fit of all simulations, we obtain information on whether the quality of competing QPE methods is significantly different. This knowledge is inferred exactly at the scale of interest—the catchment scale. We use synthetic data to investigate the ability of this procedure to distinguish a truly superior QPE from an inferior one. We find that the procedure is prone to failure in the case of linear systems. However, we show evidence that in realistic (nonlinear) settings, the method can provide useful results even in the presence of moderate errors in model structure and streamflow observations. In a real-world case study on a small mountainous catchment, we demonstrate the ability of the verification procedure to reveal additional insights as compared to a conventional cross validation approach.

Description:    Multi-walled carbon nanotubes (MWCNTs) were evaluated as potential adsorbents for miniaturized solid-phase extraction coupled to liquid chromatography. The adsorption capacity of this sorbent was applied to assess the speciation of four cobalamins representing the various forms of vitamin B 12 . The preconcentration on the MWCNTs was based on the retention of analytes by introducing the sample online into the mini-column system. Dimethyl sulfoxide was used to elute the retained vitamins for liquid chromatographic analysis. The experimental conditions of the continuous flow device, which affect the enrichment procedure, such as the type and amount of nanotubes, the volume, pH and flow rate of the sample solution, and the eluent and its volume, were optimized. For detection purposes, a diode array device was used and good resolution was obtained with a mobile-phase acetonitrile–phosphate buffer and gradient elution. Specificity was demonstrated by the retention characteristics and UV spectra and by comparing the peak purity index with commercial standards. Linearity, precision, recovery, and sensitivity were satisfactory. Detection limits ranged from 0.35 to 30 ng mL −1 . The method was successfully applied to the determination of cobalamins in seafoods, which were extracted from the sample with a buffer solution using an ultrasonic probe. The reliability of the procedure was checked by analyzing a certified reference material. Content Type Journal Article Pages 1-7 DOI 10.1007/s00216-011-5158-1 Authors Pilar Viñas, Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia, Spain Ignacio López-García, Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia, Spain María Bravo Bravo, Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia, Spain Manuel Hernández-Córdoba, Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia, Spain Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Human remains detection canines are used in locating deceased humans in diverse scenarios and environments based on odor produced during the decay process of the human body. It has been established that human remains detection canines are capable of locating human remains specifically, as opposed to living humans or animal remains, thus suggesting a difference in odor between the different sources. This work explores the collection and determination of such odors using a dynamic headspace concentration device. The airflow rate and three sorbent materials—Dukal cotton gauze, Johnson & Johnson cotton-blend gauze, and polyester material—used for odor collection were evaluated using standard compounds. It was determined that higher airflow rates and openly woven material, e.g., Dukal cotton gauze, yielded significantly less total volatile compounds due to compound breakthrough through the sorbent material. Collection from polymer- and cellulose-based materials demonstrated that the molecular backbone of the material is a factor in compound collection as well. Volatiles, including cyclic and straight-chain hydrocarbons, organic acids, sulfides, aldehydes, ketones, and alcohols, were collected from a population of 27 deceased bodies from two collection locations. The common compounds between the subjects were compared and the odor profiles were determined. These odor profiles were compared with those of animal remains and living human subjects collected in the same manner. Principal component analysis showed that the odor profiles of the three sample types were distinct. Content Type Journal Article Pages 1-13 DOI 10.1007/s00216-011-5167-0 Authors Lauryn E. DeGreeff, International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, 11200 S.W. 8th Street, Miami, FL 33199, USA Kenneth G. Furton, International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, 11200 S.W. 8th Street, Miami, FL 33199, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: I address a range of topics that provide the sociopolitical-technological setting for my professional life. I discuss some influential features of post–World War II world geopolitics, landmark technological developments of that era, and the resulting follow-up technologies that have made it possible to approach various problems in hydrology and water resources. I next address societal needs that have driven developments in hydrology and water resources engineering and follow with a discussion of the modern foundations of our science and what I think are the principal issues in hydrology. I pose three community challenges that when accomplished should advance hydrologic science: data network needs for improving the water budgets at all scales, characterizing subsurface water flow paths, and the information archiving and mining needs from instruments that will generate substantially richer data detail than have been used for most hydrologic work to the present. I then discuss several hydrologic and water resource risk-based decision issues that matter to society to illustrate how such risks have been addressed successfully in the past. I conclude with a long-term community “grand challenge,” the coupled modeling of the ocean-atmosphere-landform hydrologic cycle for the purpose of long–lead time hydrologic prediction.

Description:    A new sensitive and fast quantitative analytical method for the simultaneous determination of clopidogrel, its main metabolite clopidogrel carboxylic acid, and the newly described acyl glucuronide metabolite, in human plasma samples, is presented. The analytical procedures (plasma storage, handling, and extract storage in the autosampler) were optimized in order to avoid back-conversion; a known drawback in measurements of clopidogrel. Clopidogrel acyl glucuronide was confirmed as a major source of back-conversion to the parent drug in the presence of methanol, and thorough stability experiments were carried out to find the most appropriate conditions for an accurate analysis of clopidogrel and the two metabolites. The method was validated by assessing selectivity, sensitivity, linearity, accuracy, and precision for all three analytes, in accordance to Food and Drug Administration guidelines. Spiked quality controls in plasma as well as incurred samples were used to verify back-conversion in the selected conditions, with results meeting European Medicines Agency acceptance criteria (concentrations within 80–120% of the first reading). The method was then applied to a pharmacokinetic study, and for the first time, a pharmacokinetic curve of clopidogrel acyl glucuronide in human plasma is presented. The concentrations ranged up to 1,048.684 ng/mL, with a mean of 470.268 ng/mL, while clopidogrel had a mean C max of 1.348 ng/mL; these orders of magnitude show how much the back-conversion of this metabolite may influence clopidogrel quantification if it is not properly controlled. Content Type Journal Article Pages 1-12 DOI 10.1007/s00216-011-5147-4 Authors Luigi Silvestro, 3S-Pharmacological Consultation & Research GmbH, Koenigsbergerstrasse 1, 27243 Harpstedt, Germany Mihaela Gheorghe, Pharma Serv Int’l SRL, 52 Sabinelor Str., 5th District, 050853 Bucharest, Romania Adriana Iordachescu, Pharma Serv Int’l SRL, 52 Sabinelor Str., 5th District, 050853 Bucharest, Romania Valentin Ciuca, Pharma Serv Int’l SRL, 52 Sabinelor Str., 5th District, 050853 Bucharest, Romania Ariana Tudoroniu, Pharma Serv Int’l SRL, 52 Sabinelor Str., 5th District, 050853 Bucharest, Romania Simona Rizea Savu, 3S-Pharmacological Consultation & Research GmbH, Koenigsbergerstrasse 1, 27243 Harpstedt, Germany Isabela Tarcomnicu, Pharma Serv Int’l SRL, 52 Sabinelor Str., 5th District, 050853 Bucharest, Romania Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: The likely effects of climate change on the water resources of the eastern Mediterranean and Middle East region are investigated using a high-resolution regional climate model (PRECIS) by comparing precipitation simulations of 2040–2069 and 2070–2099 with 1961–1990. The simulations show about a 10% decline in precipitation across the region by both the middle and the end of the century, with considerable variation between countries and international river basins. Results suggest that per capita water resources will not change particularly significantly in southeastern Europe, where they are relatively plentiful and population growth is minimal. However, in much of the Middle East, climate change coupled with population growth is likely to reduce per capita water resources considerably. This will inevitably result in major social, economic, and environmental change in the region. Countries where the required adaptation is likely to be particularly challenging include Turkey and Syria because of the large agricultural workforces, Iraq because of the magnitude of the change and its downstream location, and Jordan because of its meager per capita water resources coupled with limited options for desalination. If the internal water footprint of the region declines in line with precipitation but the total water footprint of the region increases in line with population, then by midcentury, as much as half the total water needs of the region may need to be provided through desalination and imported in the form of virtual water.

Description:    In this study, we employed laser ablation/inductively coupled plasma mass spectrometry (LA-ICP-MS) to map the spatial distribution of Gd-doped iron oxide nanoparticles (IONPs) in one tumor slice that had been subjected to magnetic fluid hyperthermia (MFH). The mapping results revealed the high resolution of the elemental analysis, with the distribution of Gd atoms highly correlated with that of the Fe atoms. The spatial distributions of C, P, S, and Zn atoms revealed that the effect of MFH treatment was significantly dependent on the diffusion of the magnetic fluid in the tissue. An observed enrichment of Cu atoms after MFH treatment was probably due to inflammation in the tumor. The abnormal distribution of Ni atoms suggests a probable biochemical reaction in the tumor. Therefore, this LA-ICP-MS mapping technique can provide novel information regarding the spatial distribution of elements in tumors after cancer therapy. Figure  Mapping and ion intensities of a 56 Fe and b 158 Gd atoms. The red line indicates the path taken during the time-resolved analyses of Fe and Gd atoms Content Type Journal Article Pages 1-7 DOI 10.1007/s00216-011-5144-7 Authors Yi-Kong Hsieh, Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan Pei-Shin Jiang, Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan Bing-Shen Yang, Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan Tian-Ye Sun, Department of Environmental Science and Engineering, Tsinghua University, Beijing, 100084 China Hsu-Hsia Peng, Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan Chu-Fang Wang, Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    The new analytical method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination of diacylhydrazine insecticide residues in fruits and vegetables was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The four insecticides (tebufenozide, methoxfenozide, chromafenozide, and halofenozide) were extracted from six fruit and vegetable matrices using acetonitrile and subsequently cleaned up using primary secondary amine (PSA) or octadecylsilane (C18) as sorbent prior to UPLC-MS/MS analysis. The determination of the target compounds was achieved in less than 3.0 min using an electrospray ionization source in positive mode (ESI+) for tebufenozide, methoxfenozide, and halofenozide and in negative mode (ESI−) for chromafenozide. The limits of detection were below 0.6 μg kg −1 , while the limit of quantification did not exceed 2 μg kg −1 in different matrices. The QuEChERS procedure by using two sorbents (PSA and C18) and the matrix-matched standards gave satisfactory recoveries and relative standard deviation (RSD) values in different matrices at four spiked levels (0.01, 0.05, 0.1, and 1 mg kg −1 ). The overall average recoveries for this method in apple, grape, cucumber, tomato, cabbage, and spinach at four levels ranged from 74.2% to 112.5% with RSDs in the range of 1.4–13.8% ( n  = 5) for all analytes. This study provides a theoretical basis for China to draw up maximum residue limits and analytical method for diacylhydrazine insecticide in vegetables and fruits. Content Type Journal Article Pages 1-8 DOI 10.1007/s00216-011-5148-3 Authors Xingang Liu, Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193 China Jun Xu, Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193 China Fengshou Dong, Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193 China Yuanbo Li, Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193 China Wenchen Song, Institute for the Control of Agrochemicals, Ministry of Agriculture, Beijing, 100125 China Yongquan Zheng, Key Laboratory of Pesticide Chemistry and Application, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193 China Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: We review the human actions, proximal stressors and ecological responses for floodplain forests Australia's largest river system—the Murray-Darling Basin. A conceptual model for the floodplain forests was built from extensive published information and some unpublished results for the system, which should provide a basis for understanding, studying and managing the ecology of floodplains that face similar environmental stresses. Since European settlement, lowlands areas of the basin have been extensively cleared for agriculture and remnant forests heavily harvested for timber. The most significant human intervention is modification of river flows, and the reduction in frequency, duration and timing of flooding, which are compounded by climate change (higher temperatures and reduced rainfall) and deteriorating groundwater conditions (depth and salinity). This has created unfavorable conditions for all life-history stages of the dominant floodplain tree (Eucalyptus camaldulensis Dehnh.). Lack of extensive flooding has led to widespread dieback across the Murray River floodplain (currently 79% by area). Management for timber resources has altered the structure of these forests from one dominated by large, widely spreading trees to mixed-aged stands of smaller pole trees. Reductions in numbers of birds and other vertebrates followed the decline in habitat quality (hollow-bearing trees, fallen timber). Restoration of these forests is dependent on substantial increases in the frequency and extent of flooding, improvements in groundwater conditions, re-establishing a diversity of forest structures, removal of grazing and consideration of these interacting stressors.

Description:    Metabolites of synthetic pyrethroids such as cis -3-(2,2-dibromovinyl)-2,2-di-methylcyclo-propane-1-carboxylic acid, cis - and trans -3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid), 3-phenoxybenzoic acid (3-PBA), and 4-fluoro-3-PBA are biomarkers for exposure to phenothrin, tetramethrin, cyfluthrin, cypermethrin, deltamethrin, and permethrin. In this study, the pyrethroid metabolites in workers’ urine samples were monitored for the first time with a novel sample pretreatment process combining hollow fiber liquid phase microextraction (HF-LPME) and in-syringe derivatization (ISD) followed by gas chromatography–electron capture detector (GC-ECD) analysis. A micro-syringe pre-filled with derivatizing agents and syringe needle connected to an extracting solvent impregnated hollow fiber segment was used as the LPME probe. Pyrethroid metabolites were extracted and enriched simultaneously from urine samples by HF-LPME sampling and acid hydrolysis at 70 °C for 10 min. After sampling, the ISD was performed by mixing the extracting solution and derivatizing agents through plunger movements, followed by GC-ECD analysis. Parameters influencing the HF-LPME efficiency and ISD were investigated and optimized. Under optimum conditions, the method provided enrichment factors of 69.8–154.6, repeatability from 5.0 to 12% ( n  = 5), and good linearity ( R 2  = 0.9980–0.9998) for interested analytes spiked in urine samples. The method detection limits ranged from 1.6 to 17 ng/mL. A comparison was performed between the proposed method and conventional methods. The proposed method was applied to analyze pyrethroid metabolites in the urine samples collected from workers of pesticide formulation plants. The results suggested that the proposed HF-LPME coupled ISD method was a rapid, simple, efficient, and eco-friendly technique in the biomonitoring of metabolites of pyrethroids in workers’ urine. Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5122-0 Authors Chiu-Hwa Lin, Department of Chemistry, National Chung Hsing University, Taichung City, 402 Taiwan Cheing-Tong Yan, Department of Occupational Safety and Health, Chung-Shan Medical University, Taichung, 402 Taiwan Ponnusamy Vinoth Kumar, Department of Chemistry, National Chung Hsing University, Taichung City, 402 Taiwan Hong-Ping Li, Residue Control Department, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture (TACTRI/COA), Wu-Fung, Taichung City, 413 Taiwan Jen-Fon Jen, Department of Chemistry, National Chung Hsing University, Taichung City, 402 Taiwan Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    An integrated approach based on the use of inductively coupled plasma mass spectrometry (ICP-MS) and scanning electron microscopy (SEM) for the qualitative and quantitative analyses of metal particles in foods was devised and validated. Different raw materials and food products, like wheat, durum wheat, wheat flour, semolina, cookies, and pasta were considered. Attention was paid to the development of sample treatment protocols for each type of sample to avoid potential artifacts such as aggregation or agglomeration. The analytical protocols developed followed by ICP-MS and SEM investigations allowed us the quantitative determination and the morphological and dimensional characterization of metal nano- and microparticles isolated from the raw materials and finished food products considered. The ICP-MS method was validated in terms of linearity (0.8–80 μg/g and 0.09–9 μg/g for Fe and Ti, respectively), quantification limits (0.73 μg/g for Fe and 0.09 μg/g for Ti), repeatability (relative standard deviation (RSD) % equal to 10% for Fe and 20% in a wheat matrix as an example), and extraction recoveries (93 ± 2–101 ± 2%). Validation of the scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDS) measurements was performed working in a dimensional range from 1 to 100 μm with an estimated error in the size determination equal to 0.5 μm. ICP-MS data as well as SEM measurements showed a decrease in the concentration of metal particles from wheat to flour and from durum wheat to semolina samples, thus indicating an external contamination of grains by metal particles. These findings were confirmed by environmental SEM analysis, which allowed investigation of particles of lower dimensions. Generally, the largest number of particles was found in the case of iron and titanium, whereas particles of copper and zinc were only occasionally found without any possibility of quantifying their number. Content Type Journal Article Pages 1-9 DOI 10.1007/s00216-011-5149-2 Authors D. Beltrami, Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy D. Calestani, IMEM-CNR, Parco Area delle Scienze 37/A, 43124 Parma, Italy M. Maffini, Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy M. Suman, Barilla Food Research Labs, via Mantova 166, 43100 Parma, Italy B. Melegari, Barilla Food Research Labs, via Mantova 166, 43100 Parma, Italy A. Zappettini, IMEM-CNR, Parco Area delle Scienze 37/A, 43124 Parma, Italy L. Zanotti, IMEM-CNR, Parco Area delle Scienze 37/A, 43124 Parma, Italy U. Casellato, ICIS-CNR, Area della Ricerca, C.so Stati Uniti 4, 35127 Padova, Italy M. Careri, Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy A. Mangia, Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Electron spin resonance spectroscopy and mass spectrometry are two analytical methods that are very rarely used in combination. In this paper, we will show that the methods complement one another in the example of the distribution of stable nitroxide radicals in human skin, including the spatial resolution of these distribution processes. There are many ESR investigations dealing with this subject, but unfortunately, they are all limited to the detection of paramagnetic species. The combination with MS allows the successful examination of the distribution profile of the main biotransformation product of the nitroxide radicals, the respective “ESR-silent” hydroxylamines. In order to maintain the biological state of the sample material as far as possible, atmospheric pressure matrix-assisted laser desorption/ionization with ion trap detection has been used for the mass spectrometric investigations. The results validate the former findings of the strong reduction of stable free radicals by biological material; moreover, the diamagnetic species formed during these processes have been identified. Figure  Comparison of the ESR and MS results concerning the distribution of the nitroxide radical CAT-1 and CAT-1-H in a human skin biopsy Content Type Journal Article Pages 1-7 DOI 10.1007/s00216-011-5150-9 Authors U. Hochkirch, Institute of Chemistry, Humboldt-Universität zu Berlin, 10117 Berlin, Germany W. Herrmann, Institute of Pharmacy, Free University Berlin, Kelchstr. 31, 12169 Berlin, Germany R. Stößer, Institute of Chemistry, Humboldt-Universität zu Berlin, 10117 Berlin, Germany M. Linscheid, Institute of Chemistry, Humboldt-Universität zu Berlin, 10117 Berlin, Germany H.-H. Borchert, Institute of Pharmacy, Free University Berlin, Kelchstr. 31, 12169 Berlin, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Fine needle aspirates (FNAs) of suspicious breast lesions are often used to aid the diagnosis of female breast cancer. Biospectroscopy tools facilitate the acquisition of a biochemical cell fingerprint representative of chemical bonds present in a biological sample. The mid-infrared (IR; 4,000–400 cm −1 ) is absorbed by the chemical bonds present, allowing one to derive an absorbance spectrum. Complementary to IR spectroscopy, Raman spectroscopy measures the scattering by chemical bonds following excitation by a laser to generate an intensity spectrum. Our objective was to apply these methods to determine whether a biospectroscopy approach could objectively segregate different categories of FNAs. FNAs of breast tissue were collected ( n  = 48) in a preservative solution and graded into categories by a cytologist as C1 (non-diagnostic), C2 (benign), C3 (suspicious, probably benign) or C5 (malignant) [or C4 (suspicious, probably malignant); no samples falling within this category were identified during the collection period of the study]. Following washing, the cellular material was transferred onto BaF 2 (IR-transparent) slides for interrogation by Raman or Fourier-transform IR (FTIR) microspectroscopy. In some cases where sufficient material was obtained, this was transferred to low-E (IR-reflective) glass slides for attenuated total reflection–FTIR spectroscopy. The spectral datasets produced from these techniques required multivariate analysis for data handling. Principal component analysis followed by linear discriminant analysis was performed independently on each of the spectral datasets for only C2, C3 and C5. The resulting scores plots revealed a marked overlap of C2 with C3 and C5, although the latter pair were both significantly segregated ( P  〈 0.001) in the Raman spectra. Good separation was observed between C3 and C5 in all three spectral datasets. Analysis performed on the average spectra showed the presence of three distinct cytological groups. Our findings suggest that biospectroscopy tools coupled with multivariate analysis may support the current FNA tests whilst increasing the sensitivity and associated reliability for improved diagnostics. Figure  Average IR spectra derived from different categories of FNA specimens Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5137-6 Authors Jemma G. Kelly, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Abdullah A. Ahmadzai, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Paul Hermansen, Lancashire Teaching Hospitals NHS Trust, Sharoe Green Lane, Fulwood, Preston, PR2 9HT UK Mark A. Pitt, Lancashire Teaching Hospitals NHS Trust, Sharoe Green Lane, Fulwood, Preston, PR2 9HT UK Zuhair Saidan, Lancashire Teaching Hospitals NHS Trust, Sharoe Green Lane, Fulwood, Preston, PR2 9HT UK Pierre L. Martin-Hirsch, Lancashire Teaching Hospitals NHS Trust, Sharoe Green Lane, Fulwood, Preston, PR2 9HT UK Francis L. Martin, Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ UK Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    A new resistance-type sensor based on Prussian blue film has been fabricated for the detection of chlorobenzene vapor. The effect of Prussian blue preparation conditions on the response of sensor was studied. The sensor exhibited good response and selectivity to chlorobenzene vapor. The sensor prepared with Fe 2 (SO 4 ) 3 at 298 K has response 8.5 at operating voltage of 10 V. The selectivity of the sensor to chlorobenzene against all other tested gases is exceeding almost by 5.6 times. The sensor showed linear response to chlorobenzene vapor in the concentration range of 24–169 ppm at room temperature and at a 10 V operating voltage. The response and recovery time of the sensor was about 18 and 12 s, respectively. Sensor stability test indicated the sensor had a good stability. Furthermore, seven real samples of chlorobenzene vapor was measured using the sensor. The relative error was in the range of about ±1.3%. Figure  Response to different gases of the sensor based on Prussian blue prepared with Fe 2 (SO 4 ) 3 at 298 K Content Type Journal Article Pages 1-6 DOI 10.1007/s00216-011-5143-8 Authors Tiexiang Fu, Department of Chemistry, Changsha University of Science and Technology, Wanjiali Road, Changsha, 410004 Hunan, China Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: There is currently a distinct gap between what climate science can provide and information that is practically useful for (and needed by) natural resource managers. Improved understanding, and model representations, of interactions between the various climate drivers (both regional and global scale), combined with increased knowledge about the interactions between climate processes and hydrological processes at the regional scale, is necessary for improved attribution of climate change impacts, forecasting at a range of temporal scales and extreme event risk profiling (e.g., flood, drought, and bushfire). It is clear that the science has a long way to go in closing these research gaps; however, in the meantime water resource managers in the Murray-Darling Basin, and elsewhere, require hydroclimatic projections (i.e., seasonal to multidecadal future scenarios) that are regionally specific and, importantly, take into account the impacts, and associated uncertainties, of both natural climate variability and anthropogenic change. The strengths and weaknesses of various approaches for supplying this information are discussed in this paper.

Description:    Egyptian blue has been identified in a painting from 1524 by the Italian artist Ortolano Ferrarese (Giovanni Battista Benvenuto). Egyptian blue is the oldest known synthetic pigment, invented by the Egyptians in the fourth dynasty (2613–2494  bc ) of the Old Kingdom and extensively used throughout Antiquity. From about 1000  a.d ., it disappeared from the historical record and was only reinvented in the late nineteenth and early twentieth century. The discovery of Egyptian blue in Ortolano Ferrarese’s painting from 1524 shows that Egyptian blue was in fact available in the period from which it is normally considered not to exist. The identification of Egyptian blue is based on optical microscopy supported by energy-dispersive spectroscopy and visual light photon-induced spectroscopy, and finally confirmed by Raman microspectroscopy. Figure  St. Margaret by Giovanni Batista Benvenuto. National Gallery of Denmark. Content Type Journal Article Pages 1-7 DOI 10.1007/s00216-011-5140-y Authors Jørn Bredal-Jørgensen, School of Conservation, Esplanaden 34, 1263 Copenhagen K, Denmark Jana Sanyova, Laboratories of IRPA/KIK, Parc du Cinquantenaire, 1, 1000 Brussels, Belgium Vibeke Rask, School of Conservation, Esplanaden 34, 1263 Copenhagen K, Denmark Maria Louise Sargent, Ny Carlsberg Glyptotek, Dantes Plads 7, 1556 Copenhagen V, Denmark Rikke Hoberg Therkildsen, Ny Carlsberg Glyptotek, Dantes Plads 7, 1556 Copenhagen V, Denmark Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: We use the Budyko framework to calculate catchment-scale evapotranspiration (E) and runoff (Q) as a function of two climatic factors, precipitation (P) and evaporative demand (Eo = 0.75 times the pan evaporation rate), and a third parameter that encodes the catchment properties (n) and modifies how P is partitioned between E and Q. This simple theory accurately predicted the long-term evapotranspiration (E) and runoff (Q) for the Murray-Darling Basin (MDB) in southeast Australia. We extend the theory by developing a simple and novel analytical expression for the effects on E and Q of small perturbations in P, Eo, and n. The theory predicts that a 10% change in P, with all else constant, would result in a 26% change in Q in the MDB. Future climate scenarios (2070–2099) derived using Intergovernmental Panel on Climate Change AR4 climate model output highlight the diversity of projections for P (±30%) with a correspondingly large range in projections for Q (±80%) in the MDB. We conclude with a qualitative description about the impact of changes in catchment properties on water availability and focus on the interaction between vegetation change, increasing atmospheric [CO2], and fire frequency. We conclude that the modern version of the Budyko framework is a useful tool for making simple and transparent estimates of changes in water availability.

Description: A partially penetrating well of length Lw and radius Rw starts to pump at constant discharge Qw at t = 0 from an unconfined aquifer of thickness D. The aquifer is of random and stationary conductivity characterized by KG (geometric mean), σY2 (log conductivity variance), and I and Iv (the horizontal and vertical integral scales). The flow problem is solved under a few simplifying assumptions commonly adopted in the literature for homogeneous media: Rw/Lw $\ll$ 1, linearization of the free surface condition, and constant drainable porosity n. Additionally, it is assumed that Rw/I 〈 1 and Lw/Iv $\gg$ 1 (to simplify the well boundary conditions) and that a first-order approximation in σY2 (extended to finite σY2 on a conjectural basis) is adopted. The solution is obtained for the mean head field $\langle$H(R, z, t)$\rangle$ and the associated water table equation. The main result of the analysis is that the flow domain can be divided into three zones for $\langle$H$\rangle$: (1) the neighborhood of the well R $\ll$ I, where $\langle$H$\rangle$ = (Qw/LwKA)h0(R, z, tKefuv/nD), with h0 being the zero-order solution pertaining to a homogeneous and isotropic aquifer, KA being the conductivity arithmetic mean, and Kefuv being the effective vertical conductivity in mean uniform flow, (2) an exterior zone R ⪆ I in which $\langle$H$\rangle$ = (Qw/LwKefuh)h0(R$\sqrt{K_{efuv}/K_{efuh}}$, z, tKefuv/nD), with Kefuh being the horizontal effective conductivity, and (3) an intermediate zone in which the solution requires a few numerical quadratures, not carried out here. The application to pumping tests reveals that identification of the aquifer parameters for homogeneous and anisotropic aquifers by commonly used methods can be applied for the drawdown measured in an observation well of length Low $\gg$ Iv (to ensure exchange of space and ensemble head averages) in the second zone in order to identify Kefuh, Kefuv, and n. In contrast, the use of the drawdown in the well (first zone) leads to an overestimation of Kefuh by the factor KA/Kefuh.

Description: Calcium (Ca) has declined to levels threatening aquatic biota in lakes on the eastern Canadian Shield. Predictive models for future changes in lake Ca are generally based on catchment-scale studies, but these models rarely account for unmeasured sources of Ca supply that are common in the nearshore areas of developed lakes. In this study we utilize up to 29 years of hydrological and water chemistry data for three lakes in central Ontario that differ in degree of human intervention to demonstrate that shoreline development may exert large effects on Ca mass balances. In the relative absence of shoreline development, Red Chalk Lake exhibited what we consider to be the normal response, a reduction in Ca load from the catchment over the last three decades, leading to a reduction in lake export and lake Ca concentration. Calcium load, export, and lake water Ca concentration also fell in Harp Lake, but less than in Red Chalk Lake, because Ca loads were elevated by human activities in Harp Lake's moderately developed shoreline area. By contrast, Dickie Lake experienced an exceptional change in Ca dynamics: both export and lake concentrations rose because of elevated load from the shoreline area linked to the use of dust suppressants on gravel roads. Reductions in both stream Ca concentration and flow volume have led to calcium decline in streams and lakes. Long-term soil acidification processes and climatic variability with its link to hydrology can explain the general pattern of Ca decline in lakes on the south-central Canadian Shield. However, given the widespread lakeshore development and use of dust suppressants on gravel roads, predictions of lake Ca levels need to take into account nearshore activities, especially those that augment rates of Ca supply.

Description: Accurate description of the soil water retention curve (SWRC) at low water contents is important for simulating water dynamics and biochemical vadose zone processes in arid environments. Soil water retention data corresponding to matric potentials of less than −10 MPa, where adsorptive forces dominate over capillary forces, have also been used to estimate soil specific surface area (SA). In the present study, the dry end of the SWRC was measured with a chilled-mirror dew point psychrometer for 41 Danish soils covering a wide range of clay (CL) and organic carbon (OC) contents. The 41 soils were classified into four groups on the basis of the Dexter number (n = CL/OC), and the Tuller-Or (TO) general scaling model describing water film thickness at a given matric potential ( 10. A strong correlation between the ratio of the two surface area estimates and the Dexter number was observed and applied as an additional scaling function in the TO model to rescale the soil water retention curve at low water contents. However, the TO model still overestimated water film thickness at potentials approaching ovendry condition (about −800 MPa). The semi–log linear Campbell-Shiozawa-Rossi-Nimmo (CSRN) model showed better fits for all investigated soils from −10 to −800 MPa and yielded high correlations with CL and SA. It is therefore recommended to apply the empirical CSRN model for predicting the dry part of the water retention curve (−10 to −800 MPa) from measured soil texture or surface area. Further research should aim to modify the more physically based TO model to obtain better descriptions of the SWRC in the very dry range (−300 to −800 MPa).

Description:    Chlorophyll a fluorescence has been extensively studied over the last few years. As demonstrated, this phenomenon is closely related to the state of photosystem II, which plays a leading role in the photosynthetic process, and therefore it has become a powerful tool to investigate this complex and any damage occurring in it as a result of physical or chemical stresses. This means that by using photosynthetic organisms as biological probes, one can consider chlorophyll a fluorescence as one of the techniques of choice to reveal the presence of some hazardous toxicants widely spread in the environment. Herbicides, pesticides, and heavy metals, whose concentration in water and food products is generally subject to extremely severe restrictions, are a concrete example of compounds detectable by chlorophyll a fluorescence. These dangerous substances react with the photosystem II, modifying the fluorescence emitted and giving responses which vary in a concentration-dependent manner. The possibility of performing easy, fast, and direct measurements of the fluorescence, even under light conditions, has opened new frontiers for the analysis in situ of pollutants. The aim of this review is to give an overview of the different techniques based on chlorophyll a fluorescence spectrometry, focusing in particular on those which represented the starting point for applications addressed to the assessment of toxic compounds in environmental samples. Content Type Journal Article Pages 1-13 DOI 10.1007/s00216-011-5166-1 Authors K. Buonasera, National Research Council (CNR), Institute of Crystallography, Rome I Research Area, Via Salaria Km 29, 300, 00015 Monterontodo Scalo, Rome, Italy M. Lambreva, National Research Council (CNR), Institute of Crystallography, Rome I Research Area, Via Salaria Km 29, 300, 00015 Monterontodo Scalo, Rome, Italy G. Rea, National Research Council (CNR), Institute of Crystallography, Rome I Research Area, Via Salaria Km 29, 300, 00015 Monterontodo Scalo, Rome, Italy E. Touloupakis, National Research Council (CNR), Institute of Crystallography, Rome I Research Area, Via Salaria Km 29, 300, 00015 Monterontodo Scalo, Rome, Italy M. T. Giardi, National Research Council (CNR), Institute of Crystallography, Rome I Research Area, Via Salaria Km 29, 300, 00015 Monterontodo Scalo, Rome, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Because of the emergence of dried blood spots (DBS) as an attractive alternative to conventional venous plasma sampling in many pharmaceutical companies and clinical laboratories, different analytical approaches have been developed to enable automated handling of DBS samples without any pretreatment. Associated with selective and sensitive MS–MS detection, these procedures give good results in the rapid identification and quantification of drugs (generally less than 3 min total run time), which is desirable because of the high throughput requirements of analytical laboratories. The objective of this review is to describe the analytical concepts of current direct DBS techniques and to present their advantages and disadvantages, with particular focus on automation capacity and commercial availability. Finally, an overview of the different biomedical applications in which these concepts could be of major interest will be presented. Figure  Direct analysis of dried blood spots Content Type Journal Article Pages 1-14 DOI 10.1007/s00216-011-5161-6 Authors Julien Déglon, Unit of Toxicology, CURML, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland Aurélien Thomas, Unit of Toxicology, CURML, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland Patrice Mangin, Unit of Toxicology, CURML, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland Christian Staub, Unit of Toxicology, CURML, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Perry G. Wang (Ed.): Monolithic chromatography and its modern applications Content Type Journal Article Pages 1-2 DOI 10.1007/s00216-011-5175-0 Authors Frantisek Svec, Lawrence Berkeley National Laboratory, The Molecular Foundry, Mailstop 67R6110, Berkeley, CA 94720, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    There is currently a renewed focus aimed at understanding allosteric mechanisms at atomic resolution. This current interest seeks to understand how both changes in protein conformations and changes in protein dynamics contribute to relaying an allosteric signal between two ligand binding sites on a protein (e.g., active and allosteric sites). Both nuclear magnetic resonance (NMR), by monitoring protein dynamics directly, and hydrogen/deuterium exchange, by monitoring solvent accessibility of backbone amides, offer insights into protein dynamics. Unfortunately, many allosteric proteins exceed the size limitations of standard NMR techniques. Although hydrogen/deuterium exchange as detected by mass spectrometry (H/DX-MS) offers an alternative evaluation method, any application of hydrogen/deuterium exchange requires that the property being measured functions in both H 2 O and D 2 O. Due to the promising future H/DX-MS has in the evaluation of allosteric mechanisms in large proteins, we demonstrate an evaluation of allosteric regulation in D 2 O. Exemplified using phenylalanine inhibition of rabbit muscle pyruvate kinase, we find that binding of the inhibitor is greatly reduced in D 2 O, but the effector continues to elicit an allosteric response. Figure  Determining allosteric coupling in H 2 O vs D 2 O. K app-Phe as a function of the concentration of PEP Content Type Journal Article Pages 1-4 DOI 10.1007/s00216-011-5133-x Authors Charulata B. Prasannan, Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, MS 3030, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA Antonio Artigues, Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, MS 3030, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA Aron W. Fenton, Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, MS 3030, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    We describe a fast and robust ultra performance liquid chromatography tandem mass spectrometry method for the quantification of phospholipid (PL) species in EDTA-plasma samples. We quantified total phosphatidylcholine (PC), phosphatidylethanolamine (PE), lysophosphatidylcholine (LPC), and sphingomyelin (SM) and several species within these classes using one or two external calibrators and one internal standard for each class. Inter-assay coefficients of variation were 〈10% for the most abundant species and 〈20% for all quantified PC, LPC, and SM species and the three most abundant PE species. Coefficients of linear regression were R 2  〉 0.98. Mean recoveries were between 83% and 123%. The limits of detection were 0.37 μmol/L for PC, 4.02 μmol/L for LPC, 3.75 μmol/L for PE, and 0.86 μmol/L for SM. Quantification was linear over the physiological ranges for PE, LPC, and SM and up to 500 μmol/L for PC. The concentrations of PLs in the plasma of healthy donors yielded results that were comparable with those of previous works. Content Type Journal Article Pages 1-9 DOI 10.1007/s00216-011-5154-5 Authors Yannick Rabagny, Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Building 57, 66421 Homburg/Saar, Germany Wolfgang Herrmann, Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Building 57, 66421 Homburg/Saar, Germany Jürgen Geisel, Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Building 57, 66421 Homburg/Saar, Germany Susanne H. Kirsch, Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Building 57, 66421 Homburg/Saar, Germany Rima Obeid, Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Building 57, 66421 Homburg/Saar, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    A simple wipe sampling procedure was developed for the surface contamination determination of ten cytotoxic drugs: cytarabine, gemcitabine, methotrexate, etoposide phosphate, cyclophosphamide, ifosfamide, irinotecan, doxorubicin, epirubicin and vincristine. Wiping was performed using Whatman filter paper on different surfaces such as stainless steel, polypropylene, polystyrol, glass, latex gloves, computer mouse and coated paperboard. Wiping and desorption procedures were investigated: The same solution containing 20% acetonitrile and 0.1% formic acid in water gave the best results. After ultrasonic desorption and then centrifugation, samples were analysed by a validated liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) in selected reaction monitoring mode. The whole analytical strategy from wipe sampling to LC–MS/MS analysis was evaluated to determine quantitative performance. The lowest limit of quantification of 10 ng per wiping sample (i.e. 0.1 ng cm −2 ) was determined for the ten investigated cytotoxic drugs. Relative standard deviation for intermediate precision was always inferior to 20%. As recovery was dependent on the tested surface for each drug, a correction factor was determined and applied for real samples. The method was then successfully applied at the cytotoxic production unit of the Geneva University Hospitals pharmacy. Figure  Wipe sampling procedure for the determination of cytotoxic drugs Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5157-2 Authors Susanne Nussbaumer, Pharmacy, Geneva University Hospitals (HUG), 1211 Geneva 14, Switzerland Laurent Geiser, Swiss Centre for Applied Human Toxicology, 1211 Geneva 4, Switzerland Farshid Sadeghipour, Pharmacy, Geneva University Hospitals (HUG), 1211 Geneva 14, Switzerland Denis Hochstrasser, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne,, 1211 Geneva 4, Switzerland Pascal Bonnabry, Pharmacy, Geneva University Hospitals (HUG), 1211 Geneva 14, Switzerland Jean-Luc Veuthey, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne,, 1211 Geneva 4, Switzerland Sandrine Fleury-Souverain, Pharmacy, Geneva University Hospitals (HUG), 1211 Geneva 14, Switzerland Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Separation of inspiratory, mixed expired and alveolar air is indispensable for reliable analysis of VOC breath biomarkers. Time resolution of direct mass spectrometers often is not sufficient to reliably resolve the phases of a breathing cycle. To realise fast on-line breath monitoring by means of direct MS utilising low-fragmentation soft ionisation, a data processing algorithm was developed to identify inspiratory and alveolar phases from MS data without any additional equipment. To test the algorithm selected breath biomarkers (acetone, isoprene, acetaldehyde and hexanal) were determined by means of quadrupole proton transfer reaction mass spectrometry (PTR-MS) in seven healthy volunteers during exercise on a stationary bicycle. The results were compared to an off-line reference method consisting of controlled alveolar breath sampling in Tedlar® bags, preconcentration by solid-phase micro extraction (SPME), separation and identification by GC-MS. Based on the data processing method, quantitative attribution of biomarkers to inspiratory, alveolar and mixed expiratory phases was possible at any time during the experiment, even under respiratory rates up to 60/min. Alveolar concentrations of the breath markers, measured by PTR-MS ranged from 130 to 2,600 ppb (acetone), 10 to 540 ppb (isoprene), 2 to 31 ppb (acetaldehyde), whereas the concentrations of hexanal were always below the limit of detection (LOD) of 3 ppb. There was good correlation between on-line PTR-MS and SPME-GC-MS measurements during phases with stable physiological parameters but results diverged during rapid changes of heart rate and minute ventilation. This clearly demonstrates the benefits of breath-resolved MS for fast on-line monitoring of exhaled VOCs. Figure  Experimental setup showing bicycle ergometer and analytical pathways: Right side PTR-MS: identification of respiratory phases by means of the new algorithm. Left side: confirmation of PTR-MS data for exhaled isoprene by means of GC-MS analysis Content Type Journal Article Pages 1-13 DOI 10.1007/s00216-011-5173-2 Authors Henny Schwoebel, Department of Anaesthesia and Intensive Care Medicine, University of Rostock, Schillingallee 70, 18057 Rostock, Germany Roland Schubert, Department of Anaesthesia and Intensive Care Medicine, University of Rostock, Schillingallee 70, 18057 Rostock, Germany Martin Sklorz, Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, University of Rostock, Dr. Lorenz Weg 1, 18059 Rostock, Germany Sabine Kischkel, Department of Anaesthesia and Intensive Care Medicine, University of Rostock, Schillingallee 70, 18057 Rostock, Germany Ralf Zimmermann, Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, University of Rostock, Dr. Lorenz Weg 1, 18059 Rostock, Germany Jochen K. Schubert, Department of Anaesthesia and Intensive Care Medicine, University of Rostock, Schillingallee 70, 18057 Rostock, Germany Wolfram Miekisch, Department of Anaesthesia and Intensive Care Medicine, University of Rostock, Schillingallee 70, 18057 Rostock, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: This paper analyzes the effects of different hydrological mechanisms on the solute response in watershed stream networks. Important processes are due to the hydraulic and chemical retention of reactive solutes in transient storage zones and the cumulative consequences of these processes from a single transport pathway as well as from the network of transport pathways. Temporal moments are derived for a distributed stream network and for a compartment-in-series model. The temporal moments are evaluated and are utilized to derive formal expressions for translating the network parameters into compartmental model parameters. The analysis reveals that in addition to the hydraulic and chemical retention processes, the morphological and topological properties of a watershed have a distinct impact on the central temporal moments in terms of averaging of the solute load weighted distances as well as the transport parameters over the network. Kinetic (rate-limited) transient storage affects second-order and higher central temporal moments and thus has a secondary effect on the parameterization of compartmental models. Additional considerable contributions to all temporal moments are introduced when parameter variability along transport pathways is considered. The paper demonstrates an improved model outcome for phosphorus transport in a small Swedish watershed by accounting for the overall network effects when parameterizing a compartment-in-series model.

Description: The estimation of hydrological model parameters by calibration to field data is a critical step in the modeling process. However, calibration often fails because of parameter correlation. Here it is shown that time-lapse gravity data can be combined with hydraulic head data in a coupled hydrogeophysical inversion to decrease parameter correlation in groundwater models. This is demonstrated for a model of riverbank infiltration where combined inversion successfully constrains hydraulic conductivity and specific yield in both an analytical and a numerical groundwater model. A sensitivity study shows that time-lapse gravity data are especially useful to constrain specific yield. Furthermore, we demonstrate that evapotranspiration, and riverbed conductance are better constrained by coupled inversion to gravity and head data than to head data alone. When estimating the four parameters simultaneously, the six correlation coefficients were reduced from unity when only head data were employed to significantly lower values when gravity and head data were combined. Our analysis reveals that the estimated parameter values are not very sensitive to the choice of weighting between head and gravity data over a large interval of relative weights.

Description: Horizontal acoustic Doppler current profilers (H-ADCPs) can be employed to estimate river discharge based on water level measurements and flow velocity array data across a river transect. A new method is presented that accounts for the dip in velocity near the water surface, which is caused by sidewall effects that decrease with the width to depth ratio of a channel. A boundary layer model is introduced to convert single-depth velocity data from the H-ADCP to specific discharge. The parameters of the model include the local roughness length and a dip correction factor, which accounts for the sidewall effects. A regression model is employed to translate specific discharge to total discharge. The method was tested in the River Mahakam, representing a large river of complex bathymetry, where part of the flow is intrinsically three-dimensional and discharge rates exceed 8000 m3 s−1. Results from five moving boat ADCP campaigns covering separate semidiurnal tidal cycles are presented, three of which are used for calibration purposes, whereas the remaining two served for validation of the method. The dip correction factor showed a significant correlation with distance to the wall and bears a strong relation to secondary currents. The sidewall effects appeared to remain relatively constant throughout the tidal cycles under study. Bed roughness length is estimated at periods of maximum velocity, showing more variation at subtidal than at intratidal time scales. Intratidal variations were particularly obvious during bidirectional flow conditions, which occurred only during conditions of low river discharge. The new method was shown to outperform the widely used index velocity method by systematically reducing the relative error in the discharge estimates.

Description: Seven high-resolution (0.3–0.6 m depth intervals), 1-D vertical profiles of the δ²H of pore water were collected across a 300 km2 study area in southern Saskatchewan, Canada, to define the vertical controls on solute transport in a 〉120 m thick, two-layered aquitard system. The 1-D profiles were augmented with an existing δ²H profile collected from a previous study. The surficial aquitard in the area consists of Quaternary deposits (either glacial till or lacustrine deposits; 13 to 128 m thick) underlain by an upper Cretaceous claystone aquitard (80–110 m thick). The shape of the individual δ²H profiles and associated 1-D transport modeling suggest diffusion is the regionally dominant vertical transport mechanism across the aquitards. The profile shape is controlled by the thickness of the Quaternary deposit and the δ²H value at the upper boundary, which coincides with the depth of the water table. The upper boundary δ²H value varies considerably across the area (−149‰ to −101‰), perhaps due to differences in local hydrological conditions (e.g., slope, aspect, infiltration) across the landscape. Modeling of all profiles shows the timing for till deposition and the timing of climate change during the Holocene are consistent across the area (∼30 ka and 7–10 ka before the present, respectively), corroborating other studies. This study provides insights into the hydrogeologic controls on solute transport in an aquitard system and associated geologic and climatic changes for a prairie region over the past 30 ka, and improves our understanding of initial and time-dependent transport boundary conditions for the study of aquitards.

Description:    A new prototype based on a microsecond pulsed glow discharge ion source coupled to a time-of-flight mass spectrometer was recently designed, constructed and analytically evaluated in our laboratory for simultaneous collection of elemental and molecular information, and as a gas-chromatographic detector of compounds of environmental concern. To investigate further the analytical capabilities of such a new setup, its capability for the determination of element ratios in volatile organic halogenated compounds has been explored. Moreover, compound-independent calibration has been carried out with the prototype as well. The results demonstrated that the intensity ratios (analyte to internal standard) were linear with the corresponding ratio of concentrations. Both for chlorine and bromine (measured in the prepeak) and for BrC (measured in the plateau) the slope was 1 and the intercept was 0. Moreover, detection limits were improved by more than 1 order of magnitude as compared with using external calibration. The applicability of the proposed approach has been demonstrated for the straightforward determination of chloroform in drinking and river waters. Figure  The ability of a new GC-μsGD-MS(TOF) prototype for the determination of elemental ratios and compound-independent calibration of organic analytes has been successfully evaluated Content Type Journal Article Pages 1-7 DOI 10.1007/s00216-011-5145-6 Authors Auristela Solà-Vázquez, Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julián Clavería 8, 33006 Oviedo, Spain José M. Costa-Fernández, Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julián Clavería 8, 33006 Oviedo, Spain Rosario Pereiro, Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julián Clavería 8, 33006 Oviedo, Spain Alfredo Sanz-Medel, Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julián Clavería 8, 33006 Oviedo, Spain Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: We develop a novel method of parameterization for spatial hydraulic property characterization to mitigate the challenges associated with the nonlinear inverse problem of subsurface flow model calibration. The parameterization is performed by the projection of the estimable hydraulic property field onto an orthonormal basis derived from the grid connectivity structure. The basis functions represent the modal shapes or harmonics of the grid, are defined by a modal frequency, and converge to special cases of the discrete Fourier series under certain grid geometries and boundary assumptions; therefore, hydraulic property updates are performed in the spectral domain and merge with Fourier analysis in ideal cases. Dependence on the grid alone implies that the basis may characterize any grid geometry, including corner point and unstructured, is model independent, and is constructed off-line and only once prior to flow data assimilation. We apply the parameterization in an adaptive multiscale model calibration workflow for three subsurface flow models. Several different grid geometries are considered. In each case the prior hydraulic property model is updated using a parameterized multiplier field that is superimposed onto the grid and assigned an initial value of unity at each cell. The special case corresponding to a constant multiplier is always applied through the constant basis function. Higher modes are adaptively employed during minimization of data misfit to resolve multiscale heterogeneity in the geomodel. The parameterization demonstrates selective updating of heterogeneity at locations and spatial scales sensitive to the available data, otherwise leaving the prior model unchanged as desired.

Description:    An ultra-high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry method for the direct analysis in oral fluid (OF) of several abused drugs and metabolites in a single chromatographic run was set up and validated. Amphetamine, methamphetamine, morphine, O -6-monoacetylmorphine, cocaine, codeine, methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine, methylenedioxyamphetamine, methadone, benzoylecgonine (BEG), Δ9-tetrahydrocannabinol (THC), ketamine, and cocaethylene were determined in a single chromatographic run with no sample pretreatment, after addition of the respective deuterated internal standards. The method was designed to perform a confirmation analysis on the residual OF samples after the preliminary on-site screening test, and it was applied on preservative buffers from different devices (Mavand Rapidstat, Concateno DDS, and Greiner Bio-One) or on neat OF samples. The method was suitable to be applied to the small amounts of sample available for the confirmatory analysis after the preliminary on-site screening or on undiluted OF samples. Limits of detection varied from 5 (morphine) to 0.2 ng/mL (methamphetamine, MDMA, BEG, and cocaethylene). The method was linear for all the substances involved, giving quadratic correlation coefficients of 〉0.99 in all the different preservative buffers checked. In addition, repeatability and accuracy were satisfactory for the majority of the substances, except for a few cases. The developed method was subsequently applied to 466 residual samples from on-site screening performed by police officers. Of these samples, 74 showed the presence of cocaine and metabolites; THC was detected in 49 samples. Two samples showed codeine and morphine while MDMA was detected in 11 samples and ketamine in four samples. Content Type Journal Article Pages 1-16 DOI 10.1007/s00216-011-5108-y Authors Sabina Strano-Rossi, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy Luca Anzillotti, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy Erika Castrignanò, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy Marialinda Felli, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy Giovanni Serpelloni, Department of Antidrug Policies, Presidency of the Council of Ministers, Via Po 16/A, 00198 Rome, Italy Roberto Mollica, Department of Antidrug Policies, Presidency of the Council of Ministers, Via Po 16/A, 00198 Rome, Italy Marcello Chiarotti, Institute of Legal Medicine, Università Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Chemometric analysis of a set of one-dimensional (1D) 1 H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D 1 H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin , DS ≤ 1.0% and OSCS = 0%; DS , DS 〉 1.0% and OSCS = 0%; and OSCS , OSCS 〉 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95–2.20, 3.10–5.70, and 1.95–5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95–2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10–5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% ( w / w ) levels. This study demonstrated that the combination of 1D 1 H NMR spectroscopy with multivariate chemometric methods is a nonsubjective, statistics-based approach for heparin quality control and purity assessment that, once standardized, minimizes the need for expert analysts. Figure  Contour plot from grid search of the optimal values of γ and C for the SVM model Content Type Journal Article Pages 1-17 DOI 10.1007/s00216-011-5155-4 Authors Qingda Zang, Department of Pharmacology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA David A. Keire, Division of Pharmaceutical Analysis, Food and Drug Administration, CDER, St. Louis, MO 63101, USA Lucinda F. Buhse, Division of Pharmaceutical Analysis, Food and Drug Administration, CDER, St. Louis, MO 63101, USA Richard D. Wood, Snowdon, Inc., 1 Deer Park Drive, Suite H-3, Monmouth Junction, NJ 08852, USA Dinesh P. Mital, Department of Health Informatics, School of Health Related Professions, University of Medicine and Dentistry of New Jersey, Newark, NJ 07107, USA Syed Haque, Department of Health Informatics, School of Health Related Professions, University of Medicine and Dentistry of New Jersey, Newark, NJ 07107, USA Shankar Srinivasan, Department of Health Informatics, School of Health Related Professions, University of Medicine and Dentistry of New Jersey, Newark, NJ 07107, USA Christine M. V. Moore, Office of New Drug Quality Assessment, Food and Drug Administration, CDER, Silver Spring, MD 20993, USA Moheb Nasr, Office of New Drug Quality Assessment, Food and Drug Administration, CDER, Silver Spring, MD 20993, USA Ali Al-Hakim, Office of New Drug Quality Assessment, Food and Drug Administration, CDER, Silver Spring, MD 20993, USA Michael L. Trehy, Division of Pharmaceutical Analysis, Food and Drug Administration, CDER, St. Louis, MO 63101, USA William J. Welsh, Department of Pharmacology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    In the field of inhalation toxicology, progress in the development of in vitro methods and efficient exposure strategies now offers the implementation of cellular-based systems. These can be used to analyze the hazardous potency of airborne substances like gases, particles, and complex mixtures (combustion products). In addition, the regulatory authorities require the integration of such approaches to reduce or replace animal experiments. Although the animal experiment currently still has to provide the last proof of the toxicological potency and classification of a certain compound, in vitro testing is gaining more and more importance in toxicological considerations. This paper gives a brief characterization of the CULTEX® Radial Flow System exposure device, which allows the exposure of cultivated cells as well as bacteria under reproducible and stable conditions for studying cellular and genotoxic effects after the exposure at the air–liquid or air–agar interface, respectively. A commercial bronchial epithelial cell line (16HBE14o-) as well as Salmonella typhimurium tester strains were exposed to smoke of different research and commercial available cigarettes. A dose-dependent reduction of cell viability was found in the case of 16HBE14o- cells; S. typhimurium responded with a dose-dependent induction of revertants. The promising results recommend the integration of cellular studies in the field of inhalation toxicology and their regulatory acceptance by advancing appropriate validation studies. Content Type Journal Article Pages 1-8 DOI 10.1007/s00216-011-5163-4 Authors Michaela Aufderheide, CULTEX Laboratories GmbH, Feodor-Lynen-Str. 21, 30625 Hannover, Germany Stefanie Scheffler, CULTEX Laboratories GmbH, Feodor-Lynen-Str. 21, 30625 Hannover, Germany Niklas Möhle, CULTEX Laboratories GmbH, Feodor-Lynen-Str. 21, 30625 Hannover, Germany Beat Halter, Halter Engineering GmbH, Huebstr. 16, 9100 Herisau, Switzerland Dieter Hochrainer, Vor der Hardt 16, 57392 Oberkirchen, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Historical nomenclature has not always been unequivocally associated with the botanical origin of natural resins. The availability of natural resins has changed throughout the centuries and so have their trade names. Furthermore, adulterations and lack of knowledge have led to variations in the composition of the products traded under the same name. This investigation aims at a new understanding of the interrelation between the historical and modern terms for natural resins. Different Pinaceae and Pistacia resins, mastic, sandarac, copaiba balm and burgundy pitch from Vigani’s Cabinet, a 300-year-old pharmaceutical collection owned by Queens’ College, Cambridge (UK) were investigated. Related reference materials from modern collections were analysed together with natural resins derived from reliable botanical sources. The analytical method was gas chromatography/mass spectrometry (GC-MS) with and without derivatisation with trimethylsulfonium hydroxide. This technique provided detailed molecular compositions of the studied materials, which in turn led to particular data profiles of the materials. Marker molecules of Copaifera , Pinaceae, Cupressaceae and Pistacia resins were identified. By comparing the GC-MS data profiles to the reference samples, a clearer picture of the connection between nomenclature and botanical origin was obtained. With the aid of the marker molecules and data profiles, it was then possible to clarify the nomenclature of the aged resins sampled from Vigani’s Cabinet. Figure  Four drawers from the Vigani Cabinet Content Type Journal Article Pages 1-14 DOI 10.1007/s00216-011-5169-y Authors Gundel Steigenberger, Chemistry and Food Chemistry, Institute for Biochemistry, Technical University Dresden, 01062 Dresden, Germany Christoph Herm, Laboratory of Archaeometry, Academy of Fine Arts Dresden, Güntzstraße 34, 01307 Dresden, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: We present a new technique for identifying and quantifying the discharge of long residence time, regional groundwater to rivers using naturally occurring tracers measured within the river. Terrigenic 4He and 222Rn, synoptically sampled along a 100 km reach in the Fitzroy River in northern Western Australia, are used to identify areas of groundwater inflow to the river and to distinguish shallow, local and deep, regional groundwater. Models of tracer transport in the river can be numerically optimized to calculate total groundwater discharge and to separate regional and local discharge fractions. Discharge of regional groundwater composes close to 15% of the total groundwater discharge along the entire reach, varying spatially along the reach from 0% to 100% of total groundwater discharge. This method should be applicable in river systems where groundwater with elevated terrigenic helium could be discharging to the river. The ability to separate locally from regionally derived groundwater discharge has significant implications for calculating catchment water budgets, for predicting catchment response to changes in precipitation, and for sustainable management of the catchment.

Description: Mean May–September Potomac River streamflow was reconstructed from 950–2001 using a network of tree ring chronologies (n = 27) representing multiple species. We chose a nested principal components reconstruction method to maximize use of available chronologies backward in time. Explained variance during the period of calibration ranged from 20% to 53% depending on the number and species of chronologies available in each 25 year time step. The model was verified by two goodness of fit tests, the coefficient of efficiency (CE) and the reduction of error statistic (RE). The RE and CE never fell below zero, suggesting the model had explanatory power over the entire period of reconstruction. Beta weights indicated a loss of explained variance during the 1550–1700 period that we hypothesize was caused by the reduction in total number of predictor chronologies and loss of important predictor species. Thus, the reconstruction is strongest from 1700–2001. Frequency, intensity, and duration of drought and pluvial events were examined to aid water resource managers. We found that the instrumental period did not represent adequately the full range of annual to multidecadal variability present in the reconstruction. Our reconstruction of mean May–September Potomac River streamflow was a significant improvement over the Cook and Jacoby (1983) reconstruction because it expanded the seasonal window, lengthened the record by 780 years, and better replicated the mean and variance of the instrumental record. By capitalizing on variable phenologies and tree growth responses to climate, multispecies reconstructions may provide significantly more information about past hydroclimate, especially in regions with low aridity and high tree species diversity.

Description: Well-validated rainfall-runoff models are able to capture the relationships between rainfall and streamflow and to reliably estimate initial catchment states. While future streamflows are mainly dependent on initial catchment states and future rainfall, use of the rainfall-runoff models together with estimated future rainfall can produce skilful forecasts of future streamflows. This is the basis for the ensemble streamflow prediction system, but this approach has not been explored in Australia. In this paper, two conceptual rainfall-runoff models, together with rainfall ensembles or analogues based on historical rainfall and the Southern Oscillation index (SOI), were used to forecast streamflows at monthly and 3-monthly scales at two catchments in east Australia. The results showed that both models forecast monthly streamflow well when forecasts for all months were evaluated together, but their performance varied significantly from month to month. Best forecasting skills were obtained (both monthly and 3 monthly) when the models were coupled with ensemble forcings on the basis of long-term historical rainfall. SOI-based resampling of forcings from historical data led to improved forecasting skills only in the period from September to December at the catchment in Queensland. For 3 month streamflow forecasts, best skills were in the period from April to June at the catchment in Queensland and in the period from October to January for the catchment in New South Wales, both of which were the periods after the rainy season. The forecasting skills are indicatively comparable to the statistical forecasting skills using a Bayesian joint probability approach. The potential approaches for improved hydrologic modeling through conditional parameterization and for improved forecasting skills through advanced model updating and bias corrections are also discussed.

Description:    The sensitive and specific detection of analytes such as proteins in biological samples is critical for a variety of applications, for example disease diagnosis. In immunoassays a signal in response to the concentration of analyte present is generated by use of antibodies labeled with radioisotopes, luminophores, or enzymes. All immunoassays suffer to some extent from the problem of the background signal observed in the absence of analyte, which limits the sensitivity and dynamic range that can be achieved. This is especially the case for homogeneous immunoassays and surface measurements on tissue sections and membranes, which typically have a high background because of sample autofluorescence. One way of minimizing background in immunoassays involves the use of lanthanide chelate labels. Luminescent lanthanide complexes have exceedingly long-lived luminescence in comparison with conventional fluorophores, enabling the short-lived background interferences to be removed via time-gated acquisition and delivering greater assay sensitivity and a broader dynamic range. This review highlights the potential of using lanthanide luminescence to design sensitive and specific immunoassays. Techniques for labeling biomolecules with lanthanide chelate tags are discussed, with aspects of chelate design. Microtitre plate-based heterogeneous and homogeneous assays are reviewed and compared in terms of sensitivity, dynamic range, and convenience. The great potential of surface-based time-resolved imaging techniques for biomolecules on gels, membranes, and tissue sections using lanthanide tracers in proteomics applications is also emphasized. Content Type Journal Article Pages 1-18 DOI 10.1007/s00216-011-5047-7 Authors A. K. Hagan, Institute of Bioanalytical Chemistry, Center of Biotechnology and Biomedicine, Faculty of Chemistry and Mineralogy, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany T. Zuchner, Institute of Bioanalytical Chemistry, Center of Biotechnology and Biomedicine, Faculty of Chemistry and Mineralogy, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    A new transmission-based Fourier transform infrared (FTIR) spectroscopic method for the direct determination of free fatty acids (FFA) in edible oils has been developed using the developed spectral reconstitution (SR) technique. Conventional neat-oil and SR calibrations were devised by spiking hexanoic acid into FFA-free canola oil and measuring the response to added FFA at 1,712 cm −1 referenced to a baseline at 1,600 cm −1 (1,712 cm −1 /1,600 cm −1 ). To compensate for the known oil dependency of such calibration equations resulting from variation of the triacylglycerol ester (C═O) absorption with differences in oil saponification number (SN), a correction equation was devised by recording the spectra of blends of two FFA-free oils (canola and coconut) differing substantially in SN and correlating the intensity of the ester (C═O) absorption at the FFA measurement location with the intensity of the first overtone of this vibration, measured at 3,471 cm −1 /3,427 cm −1 . Further examination of the spectra of the oil blends by generalized 2D correlation spectroscopy revealed an additional strong correlation with an absorption in the near-infrared (NIR) combination band region, which led to the development of a second correction equation based on the absorbance at 4,258 cm −1 /4,235 cm −1 . The NIR-based correction equation yielded superior results and was shown to completely eliminate biases due to variations in oil SN, thereby making a single FFA calibration generally applicable to oils, regardless of SN. FTIR methodology incorporating this correction equation and employing the SR technique has been automated. Figure  SR spectra of FFA-free canola oil and coconut oil, illustrating their relative absorption profiles in the FFA measurement region (1,712 cm −1 ) (A) as well as the relative intensities of the first overtone of the triacylglycerol ester linkage ν (C═O) absorption (B), demonstrates that the correlating band (3,471 cm −1 ) can overcome oil dependency in FTIR FFA analysis of edible oils Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5036-x Authors Xiuzhu Yu, College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road Yangling, 712100 Shaanxi, China F. R. van de Voort, Department of Food Science and Agricultural Chemistry, McGill University, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada Jacqueline Sedman, Department of Food Science and Agricultural Chemistry, McGill University, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada Jin-ming Gao, College of Science, Northwest A&F University, 22 Xinong Road Yangling, 712100 Shaanxi, China Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Next-generation sequencing provides technologies which sequence whole prokaryotic and eukaryotic genomes in days, perform genome-wide association studies, chromatin immunoprecipitation followed by sequencing and RNA sequencing for transcriptome studies. An exponentially growing volume of sequence data can be anticipated, yet functional interpretation does not keep pace with the amount of data produced. In principle, these data contain all the secrets of living systems, the genotype–phenotype relationship. Firstly, it is possible to derive the structure and connectivity of the metabolic network from the genotype of an organism in the form of the stoichiometric matrix N . This is, however, static information. Strategies for genome-scale measurement, modelling and predicting of dynamic metabolic networks need to be applied. Consequently, metabolomics science—the quantitative measurement of metabolism in conjunction with metabolic modelling—is a key discipline for the functional interpretation of whole genomes and especially for testing the numerical predictions of metabolism based on genome-scale metabolic network models. In this context, a systematic equation is derived based on metabolomics covariance data and the genome-scale stoichiometric matrix which describes the genotype–phenotype relationship. Content Type Journal Article Pages 1-12 DOI 10.1007/s00216-011-4948-9 Authors Wolfram Weckwerth, Department of Molecular Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Matrix-assisted laser desorption/ionization imaging mass spectrometry was used to analyze donor eye tissue specimens for phospholipid content to evaluate lipid distribution. Phosphatidylcholines and sphingomyelins were detected in the positive ion mode using 2,5-dihydroxybenzoic acid as the matrix. During this study, unknown ion signals in the lower m/z region (less than m/z 400) were detected, mainly in the far periphery of human flat-mounted tissue but not in age-matched rhesus monkey tissue prepared in a similar manner. The unknown ion signals occurred at m/z 304, 332, 360, and 388. These ions were subjected to tandem mass spectrometry directly from the tissue sample, and exact mass measurements of extracts were prepared for further identification. These ions were identified as alkyl dimethylbenzylammonium surfactants (benzalkonium chlorides (BACs)). The classification of these species was verified by comparing an eye tissue extract to an over-the-counter eye-care product containing BACs. Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5044-x Authors Timothy J. Garrett, Clinical and Translational Science Institute, University of Florida, 1600 SW Archer Rd, Gainesville, FL 32610, USA Robert F. Menger, Department of Chemistry, University of Florida, Gainesville, FL 32610, USA William W. Dawson, Department of Ophthalmology, University of Florida, Gainesville, FL 32610, USA Richard A. Yost, Department of Chemistry, University of Florida, Gainesville, FL 32610, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Fourier-transform infrared (FTIR) imaging has been used to investigate brain tumor angiogenesis using a mice solid tumor model and bare-gold (∅ 25 nm) or BaSO 4 (∅ 500 nm) nanoparticles (NP) injected into blood vasculature. FTIR images of 20-μm-thick tissue sections were used for chemical histology of healthy and tumor areas. Distribution of BaSO 4 -NP (using the 1,218–1,159 cm −1 spectral interval) revealed clearly all details of blood vasculature with morphological abnormalities of tumor capillaries, while Au-NP (using the 1,046–1,002 cm −1 spectral interval) revealed also diffusion properties of leaky blood vessels. Diffusion of Au-NP out of vascular space reached 64 ± 29 μm, showing the fenestration of “leaky” tumor blood vessels, which should allow small NP (〈100 nm, as for Au-NP) to diffuse almost freely, while large NP should not (as for BaSO 4 -NP in this study). Therefore, we propose to develop FTIR imaging as a convenient tool for functional molecular histology imaging of brain tumor vasculature, both for identifying blood capillaries and for determining the extravascular diffusion space offered by vessel fenestration. Content Type Journal Article Pages 1-7 DOI 10.1007/s00216-011-5069-1 Authors Razia Noreen, Université de Bordeaux, CNRS UMR 5248 CBMN, 2 Rue Robert Escarpit, 33604 Pessac, France Raphael Pineau, INSERM U920, Université de Bordeaux 1, Avenue des facultés, 33604 Pessac, France Chia-Chi Chien, Institute of Physics, Academia Sinica, Nankang, Taipei, 115 Taiwan, China Mariangela Cestelli-Guidi, INFN LNF, 40 Via Enrico Fermi, 00044 Frascati-Roma, Italy Yeukuang Hwu, Institute of Physics, Academia Sinica, Nankang, Taipei, 115 Taiwan, China Augusto Marcelli, INFN LNF, 40 Via Enrico Fermi, 00044 Frascati-Roma, Italy Michel Moenner, INSERM U920, Université de Bordeaux 1, Avenue des facultés, 33604 Pessac, France Cyril Petibois, Université de Bordeaux, CNRS UMR 5248 CBMN, 2 Rue Robert Escarpit, 33604 Pessac, France Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Passive exposure to tobacco smoke causes a variety of illnesses ranging from allergic responses to cancer. Assessment of exposure to second-hand tobacco smoke (SHS), particularly among vulnerable populations enables intervention and prevention of future disease. A minimally invasive oral fluids-based onsite test to detect such exposure would create a valuable tool for researchers and clinicians. Here we describe the development of a test that uses an inexpensive reader that utilizes a CMOS image sensor to reliably quantify a reporter signal and determine nicotine exposure. The rapid lateral flow test consists of a nitrocellulose strip with a control line containing goat anti-rabbit IgG, used as an internal standard, and a test line containing BSA–cotinine conjugate. To run the test, diluted sample containing antibodies against cotinine, the major metabolite of nicotine, is mixed with protein A–gold nanoparticles and placed on the sample pad. As the sample runs up to the nitrocellulose pad, antibodies in the running buffer bind to available cotinine. If cotinine is absent, the antibodies will bind to the BSA–cotinine derivative immobilized on the test line, resulting in an intense purple–red band. The concentration of cotinine equivalents in the sample can be estimated from interpretation of the test line. In this article we describe the effect of different cotinine derivatives, oral fluid pretreatment, and application and running buffers on assay sensitivity. The test can reliably detect as little as 2 ng mL −1 cotinine equivalents. The assay is sensitive, simple, rapid, inexpensive, and easily implementable in point-of-care facilities to detect second-hand smoke exposure. Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5051-y Authors Jesus M. Gonzalez, Department of Chemistry, Lehigh University, Seeley G. Mudd Building, 6 E Packer Ave, Bethlehem, PA 18015, USA Michael W. Foley, Department of Chemistry, Lehigh University, Seeley G. Mudd Building, 6 E Packer Ave, Bethlehem, PA 18015, USA Natalie M. Bieber, Department of Chemistry, Lehigh University, Seeley G. Mudd Building, 6 E Packer Ave, Bethlehem, PA 18015, USA Peter A. Bourdelle, Department of Chemistry, Lehigh University, Seeley G. Mudd Building, 6 E Packer Ave, Bethlehem, PA 18015, USA R. Sam Niedbala, Department of Chemistry, Lehigh University, Seeley G. Mudd Building, 6 E Packer Ave, Bethlehem, PA 18015, USA Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Molecularly imprinted polymers (MIPs) are tailor-made polymers with high selectivity for a given analyte, or group of structurally related compounds. The influence of the process parameters (the moles of functional monomer and cross-linker, the selection of functional monomer and solvent) on the preparation of oseltamivir (OS)-imprinted polymers was investigated. A mathematical method for uniform design to optimize these selected parameters and to increase the MIP selectivity for template molecules was applied. The optimal conditions to synthesize MIP were 0.69 mmol 30% acrylamide (AA) + 70% 4-Vinylpyridine (4-VP) and 5.0 mmol ethylene glycol dimethacrylate (EGDMA) copolymerized in 5 ml toluene in the presence of 0.1 mmol OS. MIP showed high affinity and selectivity for separation of the template molecule from other compounds. In the present study, we have established an effective LC-MS/MS method to identify and quantify OS with good sensitivity, accuracy and precision. Figure  A Complexation; B polymerization and template removal; C MIP has high affinity to template molecule; D MIP has some affinity to template molecule analog; E MIP has no affinity to other chemicals with different type from template molecule. a Template molecule; b template molecule analog; c other chemicals Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5063-7 Authors Yajun Yang, Key Lab of New Animal Drug Project, Gansu Province, Key Lab of Veterinary Pharmaceutics Discovery, Ministry of Agriculture, Lanzhou Institute of Animal Science and Veterinary Pharmaceutics, Chinese Academy of Agricultural Sciences, No335, Jiangouyan, Xiaoxihu, Qilihe District, Lanzhou, 730050 China Jianyong Li, Key Lab of New Animal Drug Project, Gansu Province, Key Lab of Veterinary Pharmaceutics Discovery, Ministry of Agriculture, Lanzhou Institute of Animal Science and Veterinary Pharmaceutics, Chinese Academy of Agricultural Sciences, No335, Jiangouyan, Xiaoxihu, Qilihe District, Lanzhou, 730050 China Yurong Liu, Key Lab of New Animal Drug Project, Gansu Province, Key Lab of Veterinary Pharmaceutics Discovery, Ministry of Agriculture, Lanzhou Institute of Animal Science and Veterinary Pharmaceutics, Chinese Academy of Agricultural Sciences, No335, Jiangouyan, Xiaoxihu, Qilihe District, Lanzhou, 730050 China Jiyu Zhang, Key Lab of New Animal Drug Project, Gansu Province, Key Lab of Veterinary Pharmaceutics Discovery, Ministry of Agriculture, Lanzhou Institute of Animal Science and Veterinary Pharmaceutics, Chinese Academy of Agricultural Sciences, No335, Jiangouyan, Xiaoxihu, Qilihe District, Lanzhou, 730050 China Bing Li, Key Lab of New Animal Drug Project, Gansu Province, Key Lab of Veterinary Pharmaceutics Discovery, Ministry of Agriculture, Lanzhou Institute of Animal Science and Veterinary Pharmaceutics, Chinese Academy of Agricultural Sciences, No335, Jiangouyan, Xiaoxihu, Qilihe District, Lanzhou, 730050 China Xuepeng Cai, Lanzhou Institute of Veterinary Science, Chinese Academy of Agricultural Sciences, Lanzhou, 730000 China Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was applied for the identification of transformation products (TPs) of fluoroquinolone (norfloxacin and ciprofloxacin) and macrolide (azithromycin, erythromycin, and roxitromycin) antimicrobials in wastewater effluents from a Zenon hollow-fiber membrane bioreactor (MBR). The detected TPs were thoroughly characterized using the accurate mass feature for the determination of the tentative molecular formulae and MS-MS experiments for the structural elucidation of unknowns. Several novel TPs, which have not been previously reported in the literature, were identified. The TPs of azithromycin and roxithromycin, identified in MBR effluent, were conjugate compounds, which were formed by phosphorylation of desosamine moiety. Transformation of fluoroquinolones yielded two types of products: conjugates, formed by succinylation of the piperazine ring, and smaller metabolites, formed by an oxidative break-up of piperazine moiety to form the 7-[(2-carboxymethyl)amino] group. A semi-quantitative assessment of these TPs suggested that they might have contributed significantly to the overall balance of antimicrobial residues in MBR effluents and thus to the overall removal efficiency. Determination of TPs during a period of 2 months indicated a conspicuous dynamics, which warrants further research to identify microorganisms involved and treatment conditions leading to their formation. Figure  Proposed structures of the novel transformation products of antimicrobials, formed during MBR wastewater treatment. AZI TP – phosphorylated azithromycin; ROX TP -phosphorylated roxithromycin; NOR TP1 – succinyl norfloxacin; CIP TP1 – succinyl ciprofloxacin; NOR TP2 - 7-[(carboxymethyl)amino]-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid; CIP TP2 - 7-[(carboxymethyl)amino]-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid. Content Type Journal Article Pages 1-11 DOI 10.1007/s00216-011-5060-x Authors Senka Terzic, Division of Marine and Environmental Research, Rudjer Boskovic Institute, 10000 Zagreb, Croatia Ivan Senta, Division of Marine and Environmental Research, Rudjer Boskovic Institute, 10000 Zagreb, Croatia Marin Matosic, Faculty of Food Technology and Biotechnology, University of Zagreb, 10000 Zagreb, Croatia Marijan Ahel, Division of Marine and Environmental Research, Rudjer Boskovic Institute, 10000 Zagreb, Croatia Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Sediments are a pervasive source of fecal indicator bacteria (FIB) in rivers, lakes, estuaries, and oceans and may constitute a long-term reservoir of human disease. Previous attempts to quantify the flux of FIB across the sediment-water interface (SWI) are limited to extreme flow events, for which the primary mechanism of bacterial release is disruption and/or erosion of the sediment substrate. Here we report measurements of FIB flux across the SWI in a turbulent stream that is not undergoing significant erosion. The stream is formed by the steady discharge of bacteria-free disinfected and highly treated wastewater effluent to an earthen channel harboring high concentrations of FIB in the sediment from in situ growth. The flux j″ of FIB across the SWI, estimated from mass balance on FIB measurements in the water column, scales linearly with the concentration of bacteria in sediment pore fluids Cpore over a 3 decade change in both variables: $j^{\,\prime\prime}\; = \;k_m^{\rm obs} C_{\rm pore}.$ The magnitude of the observed mass transfer velocity ($\[k_m^{\rm obs}\, = \; 5\times{10^{ - 5}}\]$ m s−1) is significantly larger than values predicted for either the diffusion of bacteria across a concentration boundary layer ($k_m^{\rm diff}\, = \;8\; \times \;{10^{ - 6}}$ m s−1) or sweep and eject fluid motions at the SWI ($\[k_m^{\rm sweep}\, = \; {10^{ - 6}}\]$ m s−1) but is similar to the flux of water between the stream and its hyporheic zone estimated from dye injection experiments. These results support the hypothesis that hyporheic exchange controls the trafficking of bacteria, and perhaps other types of particulate organic matter, across the SWI in turbulent streams.

Description: Reactive transport modeling is a critical element in assessing the potential of natural attenuation of groundwater pollutants. In the present study, we developed a comprehensive quantitative model that incorporates the key processes affecting the long-term fate of complex organic compound mixtures released from coal tar–type dense nonaqueous phase liquid sources. The model framework addresses the simulation of the long-term dynamics of source zone depletion, the fate of the released compounds during reactive transport in the groundwater, the evolution of the aquifer's biogeochemical response, in particular its redox conditions, and the redox-dependent carbon isotope fractionation of selected organic compounds. The modeling framework was applied for the interpretation of observed biogeochemical and isotopic data from a well-characterized coal tar–contaminated site in northern Germany. The simulations highlight the diversity of fates of the individual compounds, which result from their widely varying physicochemical characteristics, and also how complex interactions develop over the lifetime of the contamination. The highly transient release of contaminants from the coal tar as pool and as heterogeneously distributed blobs in the source zone triggers continuously changing biogeochemical conditions and isotope signatures. The modeling results illustrate how difficult and uncertain the assessment of contaminant fate can be if the collected data cover only a small time window relative to the transport time scale. This emphasizes the need for a holistic understanding of the governing processes that control the effectiveness of monitored natural attenuation before it is implemented as a passive remediation strategy at nonaqueous phase liquid–contaminated sites.

Description:    Currently a large range of pure substance reference materials are available for calibration of doping-control methods. These materials enable traceability to the International System of Units (SI) for the results generated by World Anti-Doping Agency (WADA)-accredited laboratories. Only a small number of prohibited substances have threshold limits for which quantification is highly important. For these analytes only the highest quality reference materials that are available should be used. Many prohibited substances have no threshold limits and reference materials provide essential identity confirmation. For these reference materials the correct identity is critical and the methods used to assess identity in these cases should be critically evaluated. There is still a lack of certified matrix reference materials to support many aspects of doping analysis. However, in key areas a range of urine matrix materials have been produced for substances with threshold limits, for example 19-norandrosterone and testosterone/epitestosterone (T/E) ratio. These matrix-certified reference materials (CRMs) are an excellent independent means of checking method recovery and bias and will typically be used in method validation and then regularly as quality-control checks. They can be particularly important in the analysis of samples close to threshold limits, in which measurement accuracy becomes critical. Some reference materials for isotope ratio mass spectrometry (IRMS) analysis are available and a matrix material certified for steroid delta values is currently under production. In other new areas, for example the Athlete Biological Passport, peptide hormone testing, designer steroids, and gene doping, reference material needs still need to be thoroughly assessed and prioritised. Content Type Journal Article Pages 1-10 DOI 10.1007/s00216-011-5049-5 Authors Lindsey G. Mackay, National Measurement Institute Australia, 1 Suakin Street, Pymble, NSW 2073, Australia Rymantas Kazlauskas, National Measurement Institute Australia, 1 Suakin Street, Pymble, NSW 2073, Australia Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Laser ablation coupled to inductively coupled plasma optical emission spectrometry (LA-ICP-OES) and laser-induced breakdown spectroscopy (LIBS) were investigated for the determination of Ca, Mg, Zn and Na in milk samples. The accuracy of both methods was evaluated by comparison of the concentration found using LA-ICP-OES and LIBS with classical wet digestion associated with ICP-OES determination. The results were not fully acceptable, with biases from less than 1% to more than 60%. Matrix effects were also investigated. The sample matrix can influence the temperature, electron number density ( n e ) and other excitation characteristics in the ICP. These ICP characteristics were studied and evaluated during ablation of eight milk samples. Differences in n e (from 8.9 to 13.8 × 10 14  cm −3 ) and rotational temperature (ranging from 3,400 to 4,400 K) occurred with no correlation with trueness. LIBS results obtained after classical external calibration procedure gave degraded accuracy, indicating a strong matrix effect. The LIBS measurements clearly showed that the major problem in LA-ICP was related to the ablation process and that LIBS spectroscopy is an excellent diagnostic tool for LA-ICP techniques. Content Type Journal Article Pages 1-9 DOI 10.1007/s00216-011-5079-z Authors N. Gilon, Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France J. El-Haddad, Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France A. Stankova, Laboratoire des Sciences Analytiques, UMR CNRS 5180, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France W. Lei, Laboratoire de Spectrométrie ionique et Moléculaire, UMR CNRS 5579, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France Q. Ma, Laboratoire de Spectrométrie ionique et Moléculaire, UMR CNRS 5579, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France V. Motto-Ros, Laboratoire de Spectrométrie ionique et Moléculaire, UMR CNRS 5579, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France J. Yu, Laboratoire de Spectrométrie ionique et Moléculaire, UMR CNRS 5579, Université de Lyon, Université Claude Bernard Lyon1, 69622 Villeurbanne, France Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    The volatile compounds present in wines are responsible for the quality of the wine aroma. The analysis of these compounds requires different analytical techniques depending on the type of compounds and their concentration. The importance at sensorial level of each compound should be evaluated by using olfactometric techniques and reconstitution and omission studies. In addition, wine aroma is influenced by other factors such as wine matrix, which could affect the compounds’ volatility, decreasing or increasing their concentration in the headspace above the wine. Moreover, when a wine is consumed, several oral physiological variables could affect aroma perception. The focus of this review is to outline the most recent advances in wine aroma analysis and the most innovative techniques in trying to elucidate the main factors that influence wine aroma perception during consumption. Content Type Journal Article Pages 1-16 DOI 10.1007/s00216-011-5078-0 Authors Carolina Muñoz-González, Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, C/ Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain Juan J. Rodríguez-Bencomo, Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, C/ Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain M. Victoria Moreno-Arribas, Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, C/ Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain M. Ángeles Pozo-Bayón, Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, C/ Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Analytical biophotonics Content Type Journal Article Pages 1-2 DOI 10.1007/s00216-011-5042-z Authors Jürgen Popp, Institut für Physikalische Chemie, Friedrich-Schiller-Universitaet Jena, Helmholtzweg 4, 07743 Jena, Germany Reiner Salzer, Fachrichtung Chemie und Lebensmittelchemie, Technische Universität Dresden, 01062 Dresden, Germany Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: In recent years local, national, and international authorities have showed an increasing awareness of flood and inundation hazard, likely due to the large floods which occurred in the past years in many regions of the world. In this context, the estimation of the design flood values to be adopted for flood risk assessment or floodplain management represents a crucial factor. In the case of ungauged or scarcely gauged catchments where a sufficiently long discharge time series is missing, a relevant uncertainty is involved in the flood frequency analysis and a possible solution to reduce this uncertainty is the application of continuous simulation (CS) approaches. Because of the complex structure of this type of approaches and pursuing the parameters parsimony criteria, in the hydrological practice the approaches based on the design storm (DS) estimation are more widely known and applied, mainly for their simplicity. However, one major limit of the DS method is the choice of the “design soil moisture” conditions, representing a critical parameter for assessing the initial wetness of the basin. To that end, this study of investigating six subcatchments of the upper Tiber River basin (Central Italy), with drainage area ranging from 13 to 284 km2, proposes a procedure based on the application of the CS approach as a tool to define the design soil moisture to be afterwards incorporated into the more simple DS method. For each catchment, the procedure consists of (1) stochastic generation of long synthetic rainfall and temperature series starting from observed hourly data; (2) application of a lumped continuous rainfall-runoff model to generate synthetic discharge series and, hence, to obtain the corresponding flood frequency curves; (3) estimation of the design soil moisture, for each return period, by varying in the DS approach the initial wetness conditions of the catchment so that the peak discharge estimated by the DS method matches the one given by the synthetic flood frequency curve. Moreover, in order to apply the more simple DS approach avoiding the use of the CS one, a preliminary analysis to regionalize the design soil moisture as a function of the geo-morphological characteristics and the return period is also shown.

Description: Hydrologists routinely analyze pumping test data using conventional interpretation methods that are based on the assumption of homogeneity and that, consequently, yield single estimates of representative flow parameters. However, natural subsurface formations are intrinsically heterogeneous, and hence, the flow parameters influencing the drawdown vary as the cone of depression expands in time. In this paper a novel procedure for the analysis of pumping tests in heterogeneous confined aquifers is developed. We assume that a given heterogeneous aquifer can be represented by a homogeneous system whose flow parameters evolve in time as the pumping test progresses. At any point in time, the interpreted flow parameters are estimated using the ratio of the drawdown and its derivative observed at that particular time. The procedure is repeated for all times, yielding time-dependent estimates of transmissivity Ti(t) and storativity, Si(t). Based on the analysis of the sensitivity of drawdown to inhomogeneities in the T field, the time-dependent interpreted transmissivity values are found to be a good estimate of Tg(r), the geometric mean of the transmissivity values encompassed within a progressively increasing radius r from the well. The procedure is illustrated for Gaussian heterogeneous fields with ln(T) variances up to a value of 2. The impact of the separation distance between the pumping well and observation point on data interpretation is discussed. The results show that information about the spatial variability of the transmissivity field can be inferred from time-drawdown data collected at a single observation point.

Description: Flooding affects ecosystems by transporting water and solutes across aquatic-terrestrial interfaces, removing nutrient and organic substrate limitations, and spurring biogeochemical activity. Few studies have considered the influence of flooding on surface water–groundwater interactions. This research examines the temporally variable water storage and exchange in a stream in the McMurdo Dry Valleys (MDV) of Antarctica, where diel flood pulses occur due to glacial melt. Several MDV streams display truncated discharge peaks, suggesting water storage between the source glacier and the gauging station. We tested the hypothesis that stream braids and subsurface water storage contribute to the difference between glacial melt and stream outflow hydrographs by constructing a coupled surface water routing and subsurface water flow model. This model routes water into stream braids at high flows and allows this water to infiltrate and return to the stream via subsurface flow paths as flows recede. Our simulation demonstrates the importance of surface–subsurface water interactions in controlling the hydrograph shape. Maximum simulated discharge was sensitive to storage parameters including aquifer depth and the flooding threshold, while minimum discharge was sensitive to hydraulic conductivity. Subsurface storage volume varied by 38% over a diel cycle and stream-subsurface exchange rates varied from 0 to 0.19 m3 h−1 m−1, with exchange from the stream to the subsurface during high flows, and vice versa at low flows. These results underscore how unsteady flow can increase hyporheic interactions and ecosystem productivity, and provide support for maintaining natural stream morphology and flow regimes.

Description: Bayesian theory of model calibration provides a coherent framework for distinguishing and encoding multiple sources of uncertainty in probabilistic predictions of flooding. This paper demonstrates the use of a Bayesian approach to computer model calibration, where the calibration data are in the form of spatial observations of flood extent. The Bayesian procedure involves generating posterior distributions of the flood model calibration parameters and observation error, as well as a Gaussian model inadequacy function, which represents the discrepancy between the best model predictions and reality. The approach is first illustrated with a simple didactic example and is then applied to a flood model of a reach of the river Thames in the UK. A predictive spatial distribution of flooding is generated for a flood of given severity.

Description: Evapotranspiration rates at the catchment scale are very difficult to quantify. One possible manner to continuously observe this variable could be the estimation of sensible heat fluxes (H) across large distances (in the order of kilometers) using a large aperture scintillometer (LAS), and inverting these observations into evapotranspiration rates, under the assumption that the LAS observations are representative for the entire catchment. The objective of this paper is to assess whether measured sensible heat fluxes from a LAS over a long distance (9.5 km) can be assumed to be valid for a 102.3 km2 heterogeneous catchment. Therefore, a fully process-based water and energy balance model with a spatial resolution of 50 m has been thoroughly calibrated and validated for the Bellebeek catchment in Belgium. A footprint analysis has been performed. In general, the sensible heat fluxes from the LAS compared well with the modeled sensible heat fluxes within the footprint. Moreover, as the modeled H within the footprint has been found to be almost equal to the modeled catchment averaged H, it can be concluded that the scintillometer measurements over a distance of 9.5 km and an effective height of 68 m are representative for the entire catchment.

Description: The primary aim of this paper is to present a fuzzy probabilistic approach for optimal design and rehabilitation of water distribution systems, combining aleatoric and epistemic uncertainties in a unified framework. The randomness and imprecision in future water consumption are characterized using fuzzy random variables whose realizations are not real but fuzzy numbers, and the nodal head requirements are represented by fuzzy sets, reflecting the imprecision in customers' requirements. The optimal design problem is formulated as a two-objective optimization problem, with minimization of total design cost and maximization of system performance as objectives. The system performance is measured by the fuzzy random reliability, defined as the probability that the fuzzy head requirements are satisfied across all network nodes. The satisfactory degree is represented by necessity measure or belief measure in the sense of the Dempster-Shafer theory of evidence. An efficient algorithm is proposed, within a Monte Carlo procedure, to calculate the fuzzy random system reliability and is effectively combined with the nondominated sorting genetic algorithm II (NSGAII) to derive the Pareto optimal design solutions. The newly proposed methodology is demonstrated with two case studies: the New York tunnels network and Hanoi network. The results from both cases indicate that the new methodology can effectively accommodate and handle various aleatoric and epistemic uncertainty sources arising from the design process and can provide optimal design solutions that are not only cost-effective but also have higher reliability to cope with severe future uncertainties.

Description: This paper discusses issues arising when Tropical Rainfall Measuring Mission (TRMM) estimates of rainfall characteristics are calculated for the sparsely gauged Brazilian Amazon. The particular issue considered is the calculation of statistical uncertainty in (1) comparisons between TRMM estimates of rainfall characteristics and their corresponding rain gauge estimates and (2) interpolated estimates of rainfall characteristics, which are conditional on local TRMM estimates near ungauged sites. Three characteristics selected for particular comparison are (1) mean annual rainfall, 1998–2005, (2) mean value, over these years, of the 95% quantile of within-year daily rainfall, and (3) mean number of days in the year with rainfall of 2 mm or more. The paper demonstrates how positive spatial correlation leads to underestimation of the uncertainty in the comparisons (i.e., the standard errors of differences), so that the significance of differences, when observed, is likely to be overestimated if spatial correlation is ignored. For the three characteristics mentioned, the Matérn spatial correlation function with shape parameter $\kappa$ = 1/2, giving an exponential correlation function, was found to be adequate for modeling spatial correlation. It is also argued that the statistic 1 − b, where b is the slope of the regression of a rain gauge estimate of a rainfall characteristic on its counterpart derived from satellite instrumentation, is a measure of the errors in the satellite (spatially averaged) estimates. Finally, although issues of spatial correlation are discussed with particular reference to rainfall, it is argued that the same issues arise whenever satellite-derived estimates of a component of the water cycle must be combined with ground-based measurements.

Description: The ensemble Kalman filter (EnKF) has recently been proposed as a promising parameter estimation approach for constraining the description of rock flow properties, such as permeability and porosity, to reproduce flow measurements that are modeled as nonlinear functions of these properties. One of the key factors that strongly affect the performance of the EnKF is the quality or representativeness of the prior ensemble of property fields used to initialize the EnKF assimilation procedure. The initial ensemble is commonly constructed by assuming a known geological continuity model such as a variogram. However, geologic continuity models are derived from incomplete information and imperfect modeling assumptions, which can introduce a significant level of uncertainty into the produced models. Neglecting this important source of uncertainty can lead to systematic errors and questionable estimation results. In this paper, we investigate the performance of the EnKF under varying levels of uncertainty in the variogram model parameters. We first attempt to directly estimate variogram model parameters from flow data and show that the complex and nonunique relation they have with the flow data provides little sensitivity for an effective inversion with the EnKF. We then assess the performance of the EnKF for estimation of permeability values under uncertain and incorrect initial variogram parameters and show that any bias in specifying variogram parameters tends to persist throughout the EnKF analysis even though locally reasonable permeability updates may be obtained near observation points. More importantly, we show that when variogram parameters are specified probabilistically to account for the full range of structural variability in the initial permeability ensemble, the EnKF update results are quite promising. The results suggest that under uncertain geologic continuity, the EnKF tends to perform better if a very diverse set of property fields is used to form the initial ensemble than when a deterministic and potentially erroneous variogram model is used. Therefore, in applying the EnKF to model calibration problems, it is preferable to overestimate the uncertainty in geologic continuity and to initialize the EnKF procedure with a wide range of variability in property description than to overlook the variogram uncertainty at the risk of introducing systematic bias that cannot be corrected by the EnKF updates. The practical implications of the results in this paper are significant for designing the EnKF for realistic ensemble model calibration problems where the level of uncertainty in the initial ensemble is usually not known a priori.

Description: This paper presents a theoretical investigation of the effects of spatial heterogeneity of runoff generation on the scaling behavior of runoff timing responses. A previous modeling study on the Illinois River Basin in Oklahoma had revealed a systematic spatial trend in the relative dominance of different runoff generation mechanisms, attributable to corresponding systematic trends in landscape properties. Considering the differences in the timing of hillslope responses between the different runoff mechanisms, this paper explores their impacts on the catchment-scale runoff routing responses, including how they change with spatial scale. For this purpose we utilize a distributed, physically based hydrological model, with a fully hydraulic stream network routing component. The model is used to generate instantaneous response functions (IRF) for nested catchments of a range of sizes along the river network and quantitative measures of their shape, e.g., peak and time to peak. In order to separate the effects of soil heterogeneity from those due to basin geomorphology, the model simulations are carried out for three hypothetical cases that make assumptions regarding landscape properties (uniform, a systematic trend, and heterogeneity plus the trend), repeating these simulations under wet and dry antecedent conditions. The simulations produced expected and also surprising results. The power law relationship between the peak of the IRF and drainage area is shown to be flatter under wet conditions than under dry conditions, even though the (faster) saturation excess mechanism is more dominant under wet conditions. This result appears to be caused by partial area runoff generation: under wet conditions, the fraction of saturation area is about 30%, while under dry conditions it is less than 10% for the same input of rainfall. This means travel times associated with overland flow (which mostly contributes to the peak and time to peak) are, in fact, longer during wet conditions than during dry conditions. The power law relationship between peak and drainage area also exhibits a scaling break at around 1000 km2, which can be shown to be related to the peculiar geomorphology of the catchment.

Description:    A liquid chromatography–high resolution mass spectrometry (LC-HRMS) method for the simultaneous identification and quantification of 28 benzodiazepines, including 6 metabolites, in 50 mg of hair has been validated. Positive ion electrospray ionization and HRMS determination in full-scan mode were realized on an Orbitrap mass spectrometer at a nominal resolving power of 60,000. In-source collisional experiments were conducted to obtain additional information for a more reliable identification of the investigated drugs. HRMS in full-scan mode allowed the exact determination of molecular masses of all analytes eluting in the HPLC run, so that both the immediate and retrospective screening of results for drugs and their metabolites were available. Sample preparation consisted of an overnight incubation in phosphate buffer pH 8.4 and a subsequent liquid/liquid extraction with methylene chloride/diethyl ether (90:10). Gradient elution was performed on a Luna C18 analytical column and four deuterated analogues were used as internal standards (IS). Validation was performed using both spiked hair samples and hair samples from subjects treated with benzodiazepines. Selectivity was evaluated by analysis of 20 certified blank hair samples. Extraction efficiency and matrix effects were evaluated by analysis of true positive samples. The lowest limits of quantification (LLOQs) ranged from 1 to 10 pg/mg. Linearity was investigated in the range from LLOQ to 1,000 pg/mg, for each compound ( R 2 0.998–0.999). Mean relative errors, calculated at three concentration levels, ranged from 1 to 20% (absolute value). Precision, at concentrations higher than the LLOQs, was always less than 15% expressed as percentage relative standard deviation. After validation, the procedure was applied to real samples collected for clinical and forensic toxicology purposes from subjects who were assumed to have taken benzodiazepines. Content Type Journal Article Pages 1-17 DOI 10.1007/s00216-011-4742-8 Authors Susanna Vogliardi, Forensic Toxicology and Antidoping, Medical School, University Hospital of Padova, Via Falloppio 50, 35121 Padova, Italy Donata Favretto, Forensic Toxicology and Antidoping, Medical School, University Hospital of Padova, Via Falloppio 50, 35121 Padova, Italy Marianna Tucci, Forensic Toxicology and Antidoping, Medical School, University Hospital of Padova, Via Falloppio 50, 35121 Padova, Italy Giulia Stocchero, Forensic Toxicology and Antidoping, Medical School, University Hospital of Padova, Via Falloppio 50, 35121 Padova, Italy Santo Davide Ferrara, Forensic Toxicology and Antidoping, Medical School, University Hospital of Padova, Via Falloppio 50, 35121 Padova, Italy Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description: Brief history of the Austrian Society of Analytical Chemistry Content Type Journal Article Pages 1-6 DOI 10.1007/s00216-011-4692-1 Authors Hans Malissa, Division of Chemistry and Bioanalytics, Department of Molecular Biology, University of Salzburg, 5020 Salzburg, Austria Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642

Description:    Reactive oxygen species (ROS) are involved in the regulation of many physiological processes. However, overproduction of ROS under various cellular stresses results in cell death and organ injury and thus contributes to a broad spectrum of diseases and pathological conditions. The existence of different cellular sources for ROS and the distinct properties of individual ROS (their reactivity, lifetime, etc.) require adequate detection methods. We therefore compared different models of cellular stress and various ROS-sensitive dyes—2′,7′-dichlorodihydrofluorescein diacetate (DCF-DA), MitoSOX™, and MitoTracker® red CM-H 2 XRos—using a confocal fluorescent imaging approach, which has the advantage of not only detecting but also of localizing intracellular sources for ROS. Confocal acquisition of DCF-DA fluorescence can be combined with ROS detection by the mitochondria-specific probes MitoSOX™ and MitoTracker® red CM-H 2 XRos. Specificity was controlled using various antioxidants such as Trolox and N -acetylcysteine. Using different fluorescent ROS-sensitive probes, we detected higher ROS production equally under cell starvation (IL-3 or serum depletion), hypoxia–reoxygenation, or treatment of cells with prooxidants. The detected increase in ROS was approximately threefold in IL-3-depleted 32D cells, approximately 3.5-fold in serum-deprived NIH cells, and 2.5-fold to threefold in hypoxic HL-1 cells, and these findings agree well with previously published spectrofluorometric measurements. In some cases, electron spin resonance (ESR) spectroscopy was used for the validation of results from confocal fluorescent imaging. Our data show that confocal fluorescent imaging and ESR data are in good agreement. Under cellular stress, mitochondrial ROS are released into the cytoplasm and may participate in many processes, but they do not escape from the cell. Online abstract  Mitochondrial ROS production under cellular stress Content Type Journal Article Pages 1-8 DOI 10.1007/s00216-011-4764-2 Authors Andrey V. Kuznetsov, Cardiac Surgery Research Laboratory, Department of Heart Surgery, Innsbruck Medical University (IMU), Innrain 66, 6020 Innsbruck, Austria Ingeborg Kehrer, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Research Center of AUVA, 1200 Vienna, Austria Andrey V. Kozlov, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Research Center of AUVA, 1200 Vienna, Austria Martina Haller, Daniel Swarovski Research Laboratory, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University (IMU), 6020 Innsbruck, Austria Heinz Redl, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Research Center of AUVA, 1200 Vienna, Austria Martin Hermann, KMT Laboratory, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University (IMU), 6020 Innsbruck, Austria Michael Grimm, Cardiac Surgery Research Laboratory, Department of Heart Surgery, Innsbruck Medical University (IMU), Innrain 66, 6020 Innsbruck, Austria Jakob Troppmair, Daniel Swarovski Research Laboratory, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University (IMU), 6020 Innsbruck, Austria Journal Analytical and Bioanalytical Chemistry Online ISSN 1618-2650 Print ISSN 1618-2642