ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (150)
  • Analytical Chemistry and Spectroscopy  (112)
  • Computational Chemistry and Molecular Modeling  (27)
  • Gas chromatography  (17)
  • 1
    Electronic Resource
    Electronic Resource
    Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants (1998)
    Springer
    Chromatographia 48 (1998), S. 273-283 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Atomic emission and MS detection ; Solid-phase extraction ; Aqueous samples
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC systems to enable the determination of microcontaminants at the 0.02–1 μg L−1 level in 7–50 mL of aqueous sample. The screening was limited to compounds present in at least one heteroatom-selective GC-AED trace above a predetermined concentration level. These compounds were identified by their partial formulae (AED) and the corresponding mass spectra, which were obtained from the GC-MS chromatogram via the retention index concept. The potential of the approach was demonstrated by the identification of target compounds as well as all unknowns present in tap and waste water above the predetermined threshold of 0.05 μg L−1 (tap water) or 0.5 μg L−1 (waste water).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467683
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    On-line coupling of solid-phase extraction and gas chromatography with atomic emission detection for analysis of trace pollutants in aqueous samples (1995)
    Springer
    Chromatographia 40 (1995), S. 119-124 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Atomic emission detection ; Aqueous samples ; Solid-phase extraction ; Organophosphorus pesticides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An on-line, solid-phase extraction gas chromatography atomic-emission detection (SPE-GC-AED) system has been set up using an on-column interface to transfer 100 μl of desorbing solvent to the GC part of the system. Analytical characteristics such as recovery, precision and linearity of calibration plots were comparable with those of the off-line combination of SPE-GC-AED using organophosphorus pesticides as test compounds. The fully on-line set-up causes a marked improvement in detection because of the quantitative transfer of the analytes from the SPE module to the GC: detection limits are as low as 5–20 ng l−1 for the analysis of 10 ml raw and spiked surface water samples using the phosphorus channel. Detection levels can be further enhanced by processing up to 100 ml samples. The integrated analytical system is robust. The potential of the on-line set up has been demonstrated for the analysis of surface water and waste water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02272157
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Active-site α-helix in papain and the stability of the ion pair RS- ··· ImH+. Ab initio molecular orbital study (1980)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 17 (1980), S. 651-671 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio MO calculations, using both minimal (STO-3G) and extended (Roos-Siegbahn) basis sets are reported for the systems methanethiol-imidazole, methanethiol-imidazole-formaldehyde, and methanethiol-imidazole-formamide, which, together with a point-change representation of a long α-helix, form models for the active site of papain. It is shown that the large electric field exerted by the helix in the active-site region is responsible for the presence of the essential residues Cys 25 and His 159 in the form of an ion pair RS- ··· ImH+, which is crucial for a recently proposed mechanism for the catalytic action of the enzyme. Also, an explanation is given for the anomalies in measured pK values for these residues. Detailed studies on the (sub)systems show that minimal basis sets lack the flexibility necessary for describing the type of proton transfer involved. We conclude that α-helices are essential parts of enzymes and that they play a significant role in the catalytic process.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560170407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Gas chromatographic analysis of phenylurea herbicides following catalytic hydrolysis on silica gel (1981)
    Springer
    Chromatographia 14 (1981), S. 579-586 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Urea herbicides ; Catalytic hydrolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the rapid catalytic hydrolysis of phenylurea herbicides on silica gel at elevated temperatures. After derivatisation of the anilines produced with heptafluorobutyric acid anhydride final analysis is done on a gas chromatograph equipped with an electroncapture detector. Detection limits are in the 1–5 picogram range. The method has successfully been applied to residue analysis of water samples at the 1 ppb level. The determination of free anilines present in water samples and the potential of various techniques to be used to discriminate between free anilines and parent herbicides are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262887
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Fluorine-induced chemiluminescence detection of phosphine, alkyl phosphines and monophosphinate esters (1991)
    Springer
    Chromatographia 31 (1991), S. 342-346 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Chemiluminescence detection ; Phosphine derivatives ; Headspace analysis ; Fluorine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Phosphine, alkylated phosphines and monophosphinate esters are detected with high sensitivity in capillary gas chromatography (GC) by their chemiluminescent reactions with molecular fluorine. Detection limits are estimated to be 1.3 pg, 0.5 pg, 8 pg, and 17 pg for phosphine, trimethyl phosphine, trimethyl phosphinate ester, and triethyl phosphine, respectively. As found earlier with alkylated sulfur, selenium and tellurium compounds, the detector exhibits a linear response. For triethyl phosphine, a linear range of greater than three orders of magnitude was demonstrated. Emission spectra were obtained for the trimethyl phosphine and triethyl phosphine systems. Chemiluminescence emitters include electronically excited HCF, vibrationally excited HF, and an unknown species in the trimethyl phosphine system. Banded emission from vibrationally excited HF and a broad continuum were observed for both trimethyl phosphine and triethyl phosphine; however, HCF emission was observed only for TMP. Under the conditions employed, the principal emitter is HCF for trimethyl phosphine and HF and the unknown emitter for triethyl phosphine. This detector may have important applications in investigations of the biogeochemical cycling of phosphorus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262189
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Purity of carbon dioxide as limiting factor in trace-level analysis by on-line supercritical fluid extraction/capillary gas chromatography (1991)
    Springer
    Chromatographia 32 (1991), S. 543-545 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Supercritical fluid extraction ; GC detectors ; Purity of gases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The usefulness of several grades of carbon dioxide for online supercritical fluid extraction/capillary gas chromatography has been studied. If trace-level work has to be performed, no single grade can be recommended for all modes of detection studied. Good-quality carbon dioxide is available for use with flame ionization and thermionic detectors. With electron-capture detection, however, distinct problems still exist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02327900
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Indirect GC determination of ethephon in drinking water by a combination of reactive headspace sampling with adsorptive enrichment/thermal desorption (1993)
    Springer
    Chromatographia 37 (1993), S. 361-364 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Headspace sampling ; PTV-System ; Ethephon in drinking water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An indirect GC method is described for the determination of Ethephon in drinking water on the basis of the headspace analysis of the ethylene formed from Ethephon. In order to reach the necessary detection limit, the entire volume of the static headspace distribution is transferred into a cold injection system (CIS). There, the ethylene is adsorbed on Carbosieve SIII at 10°C and, subsequently, desorbed at 300 °C. The water vapour included in the headspace is completely eliminated through the splitting system. By means of this technique, a detection limit of 0.05 μg/l water was reached.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02272249
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    A simple closing technique for capillary column making (1980)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 3 (1980), S. 298-298 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, glass ; Closing technique for static coating ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240030607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Automated glass capillary gas chromatographic analysis of PCB and organochlorine pesticide residues in agricultural productsPresented at the XXXI International Symposium on crop Protection in Gent (Belgium). May 1979. (1979)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 2 (1979), S. 723-728 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Capillary, glass ; Separation of polychloro biphenyls ; Separation of organochlorine pesticides ; Splitless automated injection ; Residue level ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complicated PCB mixtures can be separated in individual compounds using glass capillary gas chromatography, (GC)2. Depending on extraction and clean-up procedure it is also possible to separate and determine organochlorine pesticides at the same time.This (GC)2 technique can be used to determine the contents of individual chlorinated biphenyls in milk products and animal feedstuffs and in the analysis of complicated extracts of soil and vegetable material.Practical aspects concerning connection of the capillary, automatic splitless injection, repeatability of the retention time, quality of the column with respect to separation and adsorption and degradation of DDT are discussed.The detection of individual chlorinated biphenyls is possible at the ppb level in fats and vegetable materials, using an extraction and clean-up procedure, based on saponification of the sample.Preliminary results for milk, obtained from several areas, are shown.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240021206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Analysis of dinitrofluoranthenes by high resolution capillary gas chromatography/mass spectrometry (1986)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 9 (1986), S. 515-517 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography, GC ; Fused silica capillary column ; Electron impact mass spectrometry ; Linear retention indices ; Dinitrofluoranthenes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper reports the retention indices of eighteen of the possible twenty-five dinitrofluoranthene isomers.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240090905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...