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  (50)
  • Other Sources
  • Gas chromatography  (50)
  • Springer  (50)
  • American Geophysical Union
  • Cell Press
  • International Union of Crystallography
  • 2000-2004
  • 1995-1999  (50)
  • 1990-1994
  • 1955-1959
  • 1950-1954
  • 1945-1949
  • 1999  (18)
  • 1995  (32)
  • Chemistry and Pharmacology  (48)
  • Medicine  (2)
  • Electrical Engineering, Measurement and Control Technology
Collection
  • Articles  (50)
  • Other Sources
Source
Keywords
Publisher
  • Springer  (50)
  • American Geophysical Union
  • Cell Press
  • International Union of Crystallography
  • Wiley-Blackwell  (11)
Years
  • 2000-2004
  • 1995-1999  (50)
  • 1990-1994
  • 1955-1959
  • 1950-1954
    • +
Year
Topic
  • Chemistry and Pharmacology  (48)
  • Medicine  (2)
  • Electrical Engineering, Measurement and Control Technology
  • Biology  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Adrenal tissue in the male African catfish, Clarias gariepinus: localization and steroid hormone secretion (1995)
    Springer
    Cell & tissue research 280 (1995), S. 653-657 
    Details
    ISSN: 1432-0878
    Keywords: Adrenals ; Morphology ; Steroids ; Gas chromatography ; Mass spectrometry ; Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Interrenal-like tissue in male African catfish is localized in paired organs, situated retroperitoneally anterior of the kidney. Histological and enzyme-histochemical (3β-hydroxysteroid dehydrogenase) reactions were carried out on sections of these organs in order to localize steroid-producing cells. In vitro incubations were carried out to determine the steroidogenic capacity of the interrenal-like tissue. Twenty-one steroids could be identified and quantified in the incubation medium, by means of gas chromatography followed by mass spectrometry. Cortisol, 5α-and 5β-androstanedione and androstenedione together comprised about 80% of the total steroid content. In a previous study, twenty testicular steroids were detected in plasma after castration. In the present investigation we have shown that most of these steroids can be produced by the interrenal-like tissue, which thus can be considered as an extra-testicular source of gonadal steroids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318367
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Adrenal tissue in the male African catfish, Clarias gariepinus: localization and steroid hormone secretion (1995)
    Springer
    Cell & tissue research 280 (1995), S. 653-657 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Adrenals ; Morphology ; Steroids ; Gas chromatography ; Mass spectrometry ; Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Interrenal-like tissue in male African catfish is localized in paired organs, situated retroperitoneally anterior of the kidney. Histological and enzyme-histochemical (3β-hydroxysteroid dehydrogenase) reactions were carried out on sections of these organs in order to localize steroid-producing cells. In vitro incubations were carried out to determine the steroidogenic capacity of the interrenal-like tissue. Twenty-one steroids could be identified and quantified in the incubation medium, by means of gas chromatography followed by mass spectrometry. Cortisol, 5α- and 5β-androstanedione and androstenedione together comprised about 80% of the total steroid content. In a previous study, twenty testicular steroids were detected in plasma after castration. In the present investigation we have shown that most of these steroids can be produced by the interrenal-like tissue, which thus can be considered as an extra-testicular source of gonadal steroids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318367
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Correlations between gas chromatographic retention data of polycyclic aromatic hydrocarbons and several molecular descriptors (1995)
    Springer
    Chromatographia 40 (1995), S. 532-538 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention-structure correlation ; Molecular descriptors ; Polycyclic aromatics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Statistical and factor analysis have been used to test the ability of several molecular descriptors to predict the retention indexes (I) of polycyclic aromatic hydrocarbons determined on SPB-5 and SPB-20 stationary phases. Regression analysis with both columns showed that linear regression with connectivity index and bending energy of the molecules as independent variables gave the best correlation coefficients. ΔI 20–5, considered to be a measure of the polar forces in retention, gave a good correlation with the van der Waals radii of the molecules, or strain, and bending energy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290264
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Relations between pneumatic parameters of ideal gas in a column with uniform permeability (1995)
    Springer
    Chromatographia 41 (1995), S. 15-22 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Average velocity of carrier gas ; Compressibility of carrier gas ; Pneumatic parameters of carrier gas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This report was conceived as a source for the relations between five pneumatic parameters of carrier gas-inlet and outlet pressure, inlet and outlet velocity, and average velocity. Any pair of these parameters can be independent while the remaining three can be expressed as functions of the independent pair. As the total number of the independent pairs is ten, thirty different functions describing relations between arbitrary independent pairs and dependent parameters can be identified. All thirty were derived below together with the complete set of bounds for variations of independent parameters. To derive some relations, a third order rational equation had to be solved. Some properties of that solution are discussed. A simple case of vacuum operations with zero outlet pressure has also been considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02274189
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Simulation of column efficiency in temperature programmed gas-liquid chromatography (1995)
    Springer
    Chromatographia 41 (1995), S. 37-42 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Temperature programming ; Isothermal measurements ; Column efficiency ; Dead time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary If the dependence of HETP on temperature is specified under isothermal conditions, it is possible to predict the HETP for programmed temperature elution and subsequently peak width at half-height. This requires knowledge of isothermal retention time at retention temperature, which is computed by means of a model including the variation with temperature of dead time estimated from 3 homologs with carbon number: n, (n+j), (n+jk), where n, j and k are any integers. Predicted and measured peak widths corresponded within 4–9%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02274193
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Solid phase microextraction using fused silica fibers coated with graphitized carbon black (1995)
    Springer
    Chromatographia 41 (1995), S. 678-684 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid phase micro extraction ; Graphitized carbon black ; Volatile organic compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper presents the results obtained using fused-silica fibers coated with graphitized carbon black (Carbograph-Alltech) for solid-phase microextraction (SPME). The extraction and calibration curves relative to organic micro-pollutants present in gaseous and aqueous samples are reported. Examples of applications of this extraction procedure to GC and GC-MS analysis of organic micro-pollutants in actual samples are also reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267804
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Preparation and gas chromatographic characterisation of 3-bromo-4-(4-methylbenzyloxy)azobenzene stationary phase (1995)
    Springer
    Chromatographia 41 (1995), S. 697-701 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; New stationary phase ; Packed columns ; Specific retention volumes ; Activity coefficients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The synthesis of 3-bromo-4-(4-methylbenzyloxy)azobenzene (BMBOA) and its use as a stationary phase in packed columns are described. Chromatographic characteristics such as column efficiency, polarity (McReynolds constants) and operating temperature range were studied. Retention factors, specific retention volumes and activity coefficients for alcohols, esters, ketones, aromatic hydrocarbons andn-alkanes were determined. Phenols and 2,3, and 4-chlorobenzyl chlorides were separated on the new phase. Based on experimental data some assumptions were made on the possible types of intermolecular forces between solute and solvent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267807
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Utilization of Rohrschneider's concept and Tekler equation in linear temperature programmed GC. Precalculation of retention data (1995)
    Springer
    Chromatographia 40 (1995), S. 28-32 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Linear temperature programming ; Tekler-equation extension ; Retention index precalculation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An extension of Rohrschneider's concept to the field of the linear temperature programmed gas liquid chromatography, is proposed, which is based on Antoine's equation for the temperature dependence of the reduction index of Takács et al. and Tekler. The new method presented in this paper, applied to retention data of two stationary phases of low polarity, PS-255 and OV-105, gives a new possibility of precalculating retention data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02274603
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Analysis of short chain fatty acids from different intestinal samples by capillary gas chromatography (1995)
    Springer
    Chromatographia 40 (1995), S. 550-556 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open tubular columns ; Short chain fatty acids ; Intestinal fluids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A capillary gas-liquid chromatography method for the analysis of free short chain fatty acids in intestinal samples was developed. Analytical results obtained with intestinal samples are influenced not only by high molecular mass matrix constituents but also by matrix components with a molecular weight smaller than 5000 daltons. To achieve a faithful transfer of SCFA into the chromatographic system it was important to avoid accumulation of involatile deposits on the surface of the inlet liner. Cleaning of the inlet linear lead to a significant weakening of matrix effects. The method described, using an Innowax column, is more effective, particularly with respect to precision and sensitivity, and is clearly superior to packed columns. The capillary is the column of choice for the separation of short fatty acids in samples from the small intestine and stomach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290267
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The correlation equations describing retention index data on OV-101, OV-275 and PEG 20M.n-Alkanes andn-alkynes (1995)
    Springer
    Chromatographia 41 (1995), S. 726-727 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention indices ; Correlation equations ; n-Alkenes ; n-Alkynes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The correlation equations between Kovats retention indices ofn-alkenes andn-alkynes, column temperature and number of carbon atoms in molecules of these compounds on OV-101, OV-225 and PEG 20M capillary columns have been calculated. The two variable equationI=A+B·n+C/T give a good fit and are the simplest for prctical use.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267812
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Chromatographic determination of phosphine (PH3) and hydrogen sulfide (H2S) in the headspace of anaerobic bacterial enrichments using flame photometric detection (1995)
    Springer
    Chromatographia 40 (1995), S. 399-403 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Phosphine ; Flame photometric detection ; Anaerobic bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A gas chromatographic method is presented which distinguishes phosphine from hydrogen sulfide and other possible headspace gases of anaerobic microbial cultures. In anaerobic cultures spiked with phosphine, this gas is recovered in the liquid and gaseous phase down to 10 pg per ml of gas or liquid. No biogenically produced phosphine was found. Phosphine in amounts as small as 30 ng per 1 can be stored for several days in glass bottles covered with rubber septa, filled with nitrogen, in the presence or absence of water or of an anaerobic bacterial culture. Due to the selectivity of the detector and the retention characteristics of the porous layer open tubular polymer column alkanes, alkenes and organosulfur compounds routinely found in anaerobic bacterial headspaces do not interfere with the analytical quantification of phosphine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269902
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Investigation of thermal and analytical properties of two nematic liquid crystals by gas chromatography (1995)
    Springer
    Chromatographia 40 (1995), S. 581-586 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid crystals ; Internal and external NO2 compounds ; Transition temperature ; Analytical properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Thermal and analytical properties of two liquid crystals containing internal [2-nitro, 3-methyl 4-(4-heptylbenzoyloxy) 4′-methylazobenzene] and external NO2 [2,3-dimethyl 4-(4-heptylbenzoyloxy) 4′-nitroazobenzene] have been investigated by gas chromatography. Transitions temperatures are determined by inverse gas chromatography using standard columns. Good agreement with values determined by differential scanning calorimetry are found. Analytical capabilities of the two liquid crystals are shown in glass capillary columns. Compared to examples in the literature, the crystals used separated different kinds of solutes. In addition, high molecular mass solutes were eluted at relatively low temperatures. Typical separations are observed for hydrocarbon positional isomers, aromatic hydrocarbons, geometric isomers, and volatile aroma compounds. Comparison between the performance of internal and external, NO2-liquid crystals is made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Determination of volatiles in spirits using combined stationary phases in capillary GC (1995)
    Springer
    Chromatographia 41 (1995), S. 722-725 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Mixed stationary phases ; Distilled beverages ; Direct analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The analysis of spirits with a single stationary phase is still an unsolved problem; the two amyl alcohols, ethyl acetate and acetal are not separated on a polar column, methanol and acetaldehyde coelute from an apolar column. Trials with coupled columns of different polarities showed that optimum results were obtained with a 40 m capillary column, comprising 6 m of Carbowax 20 M, 12 m of 1∶1 Carbowax 20M:OV1 mixture and 30 m of PS 264. Best results were achieved when a 1 m retention gap was used, injecting a small amount of sample and using a 7 cm syringe needle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267811
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Quantitative determination of toxic mono- and non-ortho polychlorinated biphenyls in cod liver oil after selective liquid chromatographic separation (1995)
    Springer
    Chromatographia 41 (1995), S. 585-593 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Column liquid chromatography ; Polychlorinated biphenyls ; Cod liver oil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary By application of a chromatographic column filled with Supelclean ENVI-Carb/Celite and elution with three solvents of different polarity three PCB fractions were obtained. Fraction A contained poly-ortho PCBs, Fraction B mono-ortho PCBs, and Fraction C non-ortho PCBs. The Supelclean ENVI-Carb/Celite column was used in combination with a sample preparation procedure for pre-cleaning of acid-stable chlorinated hydrocarbons such as DDT and its metabolites, HCH isomers, and regulation-relevant PCB congeners. The method was optimized using standard solutions of 55 PCB congeners, 8 chlorinated pesticides and contaminated cod liver oil samples. The influence of traces of remaining matrix on the elution profile of the organochlorine compounds on Supelclean ENVI-Carb/Celite was observed. Quantitation was carried out by GC-ECD with fused silica capillary columns of different polarity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269724
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Monitoring of nicotine in air using sorptive enrichment on polydimethylsiloxane and TD-CGC-NPD (1999)
    Springer
    Chromatographia 49 (1999), S. 520-524 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Sorptive preconcentration ; Air monitoring ; Nicotine ; Hospital air
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A novel method for the enrichment of nicotine from gaseous samples is presented. It is based on the sampling of 6 liters of air onto a cartridge packed with 100% polydimethylsiloxane (PDMS) particles. The analytes are dissolved (partitioned) into the PDMS phase which results in much better recoveries and reproducibilities compared to those obtained on common adsorbents. The PDMS tube is then placed in a thermal desorption (TD) unit connected to a CGC-NPD or CGC-MS system. The procedure was employed for routinely monitoring air in a hospital. Nicotine was typically found at levels ranging from 5 to 250 μg m−3 (ppb) depending on the location and number of smokers present. Additionally, the efficiency of nicotine filters was determined by sampling simultaneously at the filter in- and outlet and was found to be 46%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467752
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    High temperature capillary GC analysis of phytopreparations of “espinheira santa” (Maytenus ilicifolia M. andMaytenus aquifolium M. — Celastraceae), a Brazilian antiulcer plant (1995)
    Springer
    Chromatographia 40 (1995), S. 341-344 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Pentacyclic triterpenes ; Maytenus aquifolium Martius ; Maytenus ilicifolia Martius ; Phytopharmaceuticals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary We report a method for the analysis of triterpenes in aqueous alcoholic extracts ofM. ilicifolia orM. aquifolium leaves, using high temperature capillary gas chromatography in polar columns (OV-17-OH). These species are popularly known in Brazil as “espinheira santa” and have proven antiulcer properties. The method consists of the pre-concentration of the triterpenes from the aqueous alcoholic extract, followed by GC analysis, which permits the determination of the presence of friedelan-3-ol and friedelin. Direct comparison with several triterpenol standards that are usually found in falsified “espinheira santa” samples but are absent in the authentic drug, showed that GC analysis clearly allows detection of the presence of friedelan-3-ol and friedelin and, therefore, permits distinguishing between authentic and false “espinheira santa” aqueous alcoholic extracts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290367
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Rapid multiresidue screening method for organophosphate pesticides in vegetables (1995)
    Springer
    Chromatographia 40 (1995), S. 417-420 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Organophosphate pesticides ; Vegetables ; Pesticide residue analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A rapid and efficient multiresidue extraction procedure using ethyl acetate and sodium sulfate has been applied to the analysis of diazinon, methamidophos, chlorpyrifos, malathion, parathion, parathion-methyl, dimethoate and monocrotophos residues in many different kinds of vegetables. No cleanup step was required Concentrated extracts were analysed by gas chromatography with flame photometric detection in phosphorus mode. Recovery studies were performed in six kinds of matrices at two fortification levels. Recoveries were in the range 80–115%. The limit of quantification of the analytical method has been estimated as 0.01 ppm for diazinon, methamidophos and malathion, 0.03 ppm for chlorpyrifos, parathion, parathion-methyl and dimethoate and 0.1 ppm for monocrotophos. Experiments showed that potentially it should be possible to develop a rapid and universally applicable method for organophosphate pesticide residues in different matrices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    A gas chromatographic flow method for preconcentration and determination of vitamins D2 and D3 in pharmaceutical preparations (1995)
    Springer
    Chromatographia 40 (1995), S. 425-431 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Continuous preconcentration method ; Vitamins D2 and D3 ; Pharmaceutical preparations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A continuous-flow method that combines on-line preconcentration and isolation with gas chromatography for the direct determination of vitamins D2 and D3 in oily solutions is reported. A silica gel column permits preconcentration and isolation of analytes from the vitamin D matrix, although some triglyceride (ca. 25%) is also retained. To overcome problems associated with the low volatility of triglycerides, their retained fraction is further transesterified with potassium methylate to fatty acid methyl esters after elution. The proposed method was applied to the determination of vitamin D in pharmaceutical preparations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269907
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Determination of cholesterol in milk fat by gas chromatography with direct injection and sample saponification (1995)
    Springer
    Chromatographia 41 (1995), S. 23-28 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Cholesterol ; Direct injection ; Saponification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A rapid and direct gas chromatographic (GC) method for determining free cholesterol in milk fat using a capillary column and programmed-temperature vaporizerinjector was assayed. It was compared with other procedures involving saponification of fat, solvent extraction of unsaponifiable matter—with and without fractionation by thin-layer chromatography—and transformation of sterols into silyl derivatives prior to GC analysis. This paper proposes an alternative to other published procedures. Repeatability of the method was assessed and the coefficient of variation determined as 2.1%. The alternative saponification method exhibited comparable accuracy (coefficient of variation=1.8%). Recovery ranged from 99.1% to 105.6%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02274190
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Specific interactions of n-donor adsorbates with N-benzoylthiourea-copper(II) complexes chemically bonded to silica supports (1995)
    Springer
    Chromatographia 41 (1995), S. 107-111 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Metal complex stationary phases ; Specific interactions ; N-benzoylthiourea groups
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Silica was modified with γ-aminopropyltriethoxylsilane, and then the amino group was converted into an N-benzoylthiourea compound. Treatment with anhydrous CuCl2 solution, gave a copper(II) complex on the surface. In order to estimate the ability of the complex to interact specifically with electron donors, a number of retention parameters were determined for three groups of compounds showing electron-donor properties: ketones, ethers and nitroalkanes. On the basis of the results, the effect of adsorbate structure on the strength of specific interactions was established. The packings studied may be useful for the analysis of the mixtures of ketones, ethers, and nitroalkanes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02274203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Analysis of pesticide residues in fruit and vegetables by matrix solid phase dispersion (MSPD) and different gas chromatography element-selective detectors (1995)
    Springer
    Chromatographia 41 (1995), S. 685-692 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Matrix solid phase dispersion (MSPD) ; Fruit and vegetables ; Pesticide residues ; Selective detectors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A comparison between different element selective detectors for the determination of organophosphorus and organochlorine pesticide residues, from fruit and vegetables, was performed by capillary GC with electron capture detector (ECD), nitrogen phosphorus detector (NPD), flame photometric detector (FPD) in the sulphur and phosphorus modes, and mass spectrometry detector (MSD) in selected ion monitoring (SIM) mode. Pesticides were extracted from the different foodstuffs by Matrix Solid Phase Dispersion (MSPD). Recoveries of 41–108 % with relative standard deviation of 2–14 % in the concentration range 0.5–10 μg L−1 were obtained in oranges, lemons, grapefruit, pears, plums, lettuces and tomatoes. The results demonstrated that the extracts of all the samples can be analyzed by the detectors used since no interfering co-extracted compounds were detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267805
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Modelling of GC and HPLC separations of simazin and atrazin by Experimental Design methodology (1995)
    Springer
    Chromatographia 41 (1995), S. 553-560 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Gas chromatography ; Experimental design ; Modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Experimental Design methodology allows the modelling and optimization of the chromatographic separation of similar pesticides (triazine family) by GC and HPLC. The GC separation of simazin and atrazin is well modelled by a first degree equation, involving injected volume, carrier gas pressure and rising oven temperature. The LC is modelled by a second degree equation, depending on injected volume, eluent flow and composition. These calculated models allow easy optimization of the separations, using isoresponse curves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269719
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    A comparison of the critical parameters of some adsorbents employed in trapping and thermal desorption of organic pollutants (1995)
    Springer
    Chromatographia 41 (1995), S. 599-604 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Organic volatile pollutants ; Adsorbents ; Breakthrough volumes ; Thermal desorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A comparison of some adsorbents, commonly used for trapping trace volatile organic pollutants followed by thermal desorption, is presented. The evaluation has been performed on 12 compounds representative of the main classes of organic substances. Breakthrough volumes and desorption recoveries have been measured. Every adsorbent gave good results for a range of compounds, but none were able to cover all the compounds examined. Thus, a multilayer trap utilising the best features of each adsorbent was introduced with very good results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269726
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    [60] Fulleropyrrolidine functionalized polysiloxane as a stationary phase for capillary gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 293-298 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; [60] Fulleropyrrolidine polysiloxane ; High temperature stationary phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this paper, a new type of [60]fulleropyrrolidine functionalized polysiloxane in which the fullerene moieties were incorporated in the main polysiloxane chain was synthesized the first time and used as a stationary phase for capillary gas chromatography. It demonstrated high column efficiency (2600–2866 plates m−1, on a 250 μm diameter column, for naphthalenek=3.1–3.2, 120 °C), a wide operational temperature range (90–360 °C) and outstanding thermostability. It can be used at 360 °C with a baseline drift of 5∼8×10−15A. Benzene homologues, aromatic hydrocarbons, polar compounds such as alcohols, esters, ketones, anilines and phthalic diesters can be seperated well on this column.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467559
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Peak capacity in packed capillary column solvating gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 333-337 
    Details
    ISSN: 1612-1112
    Keywords: Supercritical fluid chromatography ; Gas chromatography ; Solvating gas chromatography ; Peak capacity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this paper, a general peak capacity expression was evaluated using columns containing various packing materials under solvating gas chromatography (SGC) conditions. Differing from column efficiency, peak capacity can describe both separation capability and speed when introducing the dead time into the peak capacity expression. Various factors that influence peak capacity in SGC are described, including particle pore size, chemical surface modification, particle size, column length, temperature, and pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467566
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Microwave assisted extraction and sonication of polychlorobiphenils from river sediments and risk assesment by toxic equivalency factors (1999)
    Springer
    Chromatographia 49 (1999), S. 21-27 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Microwave and ultrasonic extraction ; River sediment ; Dioxin-like polychlorobiphenyls ; Toxic equivalency factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Microwave extraction and ultrasonication of dioxin-like polychlorobiphenyls (PCBs) from sediment samples were investigated. After separation of dioxin-like PCBs from a sample matrix on an acidic-alkaline silica gel column, dioxin-like PCBs were determined by GC-ECD, using dual capillary columns. Recoveries of dioxin-like PCBs in river sediment samples exceeded 80% by both extraction techniques. Toxic equivalency factors and their use for the PCB congeners investigated were applied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467182
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Conversions of carbon monoxide oxidation over Pt−Rh alloy catalysts calculated by a new gas chromatographic technique (1999)
    Springer
    Chromatographia 49 (1999), S. 285-292 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Reversed-flow gas chromatography ; Carbon monoxide oxidation ; Bimetallic Pt−Rh catalysts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Catalytic fractional conversions of carbon monoxide to carbon dioxide over Pt−Rh alloy catalysts in the presence of excess oxygen, under steady-state or non steady-state conditions, as well as corresponding rate constants for the CO oxidation reaction were measured by using the reversed-flow gas chromatographic technique. From the variation of the conversions with temperature, maximum values of conversions were found, which depend on the catalysts nature (Pt content), while from the variation of the rate constants with temperature, activation energies for the CO oxidation reaction were determined, which also depend on the catalyst Pt content. The results suggest a synergism between Pt and Rh in the Pt−Rh bimetallic catalysts in accordance with previous works, showing that reversed-flow gas chromatography can be used with simplicity and accuracy for the kinetic study of the CO oxidation reaction, which is of technological importance for the control of air pollution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467558
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    A very thick film open-tubular trap for headspace capillary gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 321-326 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Headspace analysis ; Open-tubular trap ; Very thick film column
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An open-tubular trap with a very thick film was studied for “full on-line” headspace capillary gas chromatography, and was used as an enrichment trap for headspace sampling. The preparation of the open-tubular column with up to an 80 μm thick film, by combining both static and dynamic coating, is described in detail. The break-through volume for the open-tubular trap of different film thickness, as the loading capacity for HS sampling, does not increase linearly in proportion to the film thickness. A study of the difference between a packed adsorbent trap and an open-tubular trap shows that HS capillary GC with open-tubular trap loses less of the retention capacity, has better resolution ability and higher recovery. By independently and rapidly heating the open-tubular trap, the GC peaks may have higher resolution. Examples of successful analyses, by the opentubular trap with “full on-line” HS capillary GC, include trace aromatic hydrocarbon (1 ppm-100 ppm) in polybutadiene-styrene rubber and trace alcohol and acrylic esters (10 ppm–1000 ppm) in polyacrylate hydrous emulsion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467564
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Retention system, thermodynamic properties and structure correlations of environmental analytes (1999)
    Springer
    Chromatographia 49 (1999), S. 385-390 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Structure correlations ; Polycyclic aromatic hydrocarbons ; Polychlorinated biphenyls ; Polychlorinated pesticides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A composite chromatographic retention index system has been developed for identifying polycyclic aromatic hydrocarbons, polychlorinated biphenyls and polychlorinated pesticides. When retention indices and thermodynamic data of polycyclic aromatic hydrocarbons on 5% phenylmethylsiloxane stationary phase were compared with those obtained on polydimethylsiloxane a correlation was found between retention and electronic properties. Determination and quantitation of individual contaminants in water and sediment samples from Lake Mecoacán were achieved by capillary gas chromatography with flame ionization and electrocapture detection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467611
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Backbone modification of Chirasil-Val: Effect of nonpolar side chains on enantiomer separation in gas chromatography (1995)
    Springer
    Chromatographia 40 (1995), S. 718-723 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Enantiomer separation ; Chiral polysiloxane ; Amino acids ; Physicochemical properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The polysiloxane backbone of the gas chromatography phase Chirasil-Val has been modified by replacing one methyl group per dialkylsiloxy unit by pentyl and hexyl groups, respectively. The new phases offer the advantage of reduced polarities and softening points, while the separation factors (α) of enantiomeric pairs of N,O-trifluoroacetyl amino acid propyl esters show small but intriguing deviations from those determined on Chirasil-Val.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02315143
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    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
  • 32
    Electronic Resource
    Electronic Resource
    Reversed-phase liquid chromatography coupled on-line with capillary gas chromatography use of an anion-exchange membrane to remove an ion-pair reagent from the eluent (1995)
    Springer
    Chromatographia 40 (1995), S. 267-271 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Column liquid chromatography ; On-line coupling ; Ion-exchange membrane ; Ion-pair reagent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In order to enable the coupling of reversed-phase liquid chromatography (RPLC) with capillary gas chromatography (GC), the performance of an anion-exchange micromembrane device has been studied to remove the ion-pair reagent methanesulphonic acid from an acetonitrile/water LC eluent. The regenerant in the membrane was tetrabutylammonium hydroxide dissolved in acetonitrile/water, which effects an anion-exchange of methanesulphonate ions for regenerant hydroxide ions. The efficiency of the exchange process was found to be 99.9%. This enabled the direct introduction of the LC eluent, free of ions and with the proper acetonitrile/water ratio, into the GC. The applicability of the on-line LC-micromembrane-GC system has been illustrated for the potential drug eltoprazine, which is quantitatively recovered with a coefficient of variation for standard solutions of 3% at the 150 μg/ml analyte level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290356
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    On-line automated sample preparation-capillary gas chromatography for the analysis of plasma samples (1995)
    Springer
    Chromatographia 40 (1995), S. 500-506 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; ASPEC ; Trazodone in plasma ; Method automation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An automated sample preparation module, (the automated sample preparation with extraction columns, ASPEC), was interfaced with a capillary gas chromatograph (GC) by means of an on-column interface. The system was optimised for the determination of the antidepressant trazodone in plasma. The clean-up of untreated plasma was carried out with disposable C18 cartridges, using several washing steps. The analyte was desorbed with methanol, the extract was diluted on-line with buffer and preconcentrated on a PLRP-S trapping column. The trapping column was dried by purging with nitrogen gas. Desorption (phase switching) of the trapping column was carried out with ethyl acetate which was introduced into a retention gap using partially concurrent solvent evaporation conditions. Trazodone was determined by GC with flame ionisation detection (FID). With a 1 ml sample, this resulted in a detection limit for trazodone in plasma of 3 ng/ml. The system showed good linearity and repeatability in the range 0.01–1 μg/ml, thus covering the range of pharmacokinetic/dynamic-to-therapeutic concentrations of trazodone in plasma. Preliminary results for benzodiazepines are promising. They indicate that the use of a selective detector such as the nitrogen/phosphorus detector, is to be recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290259
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    A simple gas chromatographic method for the analysis of oxygenates in gasoline (1995)
    Springer
    Chromatographia 40 (1995), S. 607-610 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Packed column separations ; C1−C4 alcohols ; Ethers ; Gasoline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A number of oxygenated compounds such as C1−C4 alcohols, methyl tert-butyl ether (MTBE), and tertamyl methyl ether (TAME) are increasingly being used in gasoline as octane boosters and to reduce vehicular emissions. Monitoring of individual oxygenates in gasoline is important for quality control and regulatory purpose. Although, several analytical methods based on gas chromatography have been reported, a need was still felt to develop a simple and cost effective method of analysis. In this paper, a packed column gas chromatographic method is described for the analysis of C1−C4 alcohols, MTBE and TAME over a wide concentration range (2–20% V/V) in gasoline. The method involves determination of alcohols and ethers separately on two different columns. The alcohols are determined on a 20 ft column packed with poly(ethylene glycol) 400 as a stationary phase while the ethers are analysed on a 20 ft OPN-Poracil C column. The analysis of alcohols on poly(ethylene glycol) 400 column also provides data on aromatic components of gasoline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290276
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Comparison of correlation equations for the prediction of gas chromatographic separation of alkylbenzenes (1995)
    Springer
    Chromatographia 41 (1995), S. 183-186 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Correlation equation ; Alkylbenezenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A detailed statistical analysis, comparing the validity of the best literature recommended equations for prediction of retention indices of alkylbenzenes on squalane and methylsilicone stationary phases with the unified retention index concept, is presented. A comparison with literature sources shows that the unified retention index provides the smallest residual error. Hence, it can be applied for prediction purposes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267952
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Ring opening of cyclohexane over ZSM-zeolites followed by reversed-flow gas chromatography (1995)
    Springer
    Chromatographia 41 (1995), S. 227-235 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Reversed-flow technique ; Catalysis ; Ring opening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Kinetic parameters for the ring opening of cyclohexane over modified ZSM-5 zeolites can be measured simultaneously under non-steady state conditions using reversed-flow gas chromatography. At relatively low temperatures, the main product detected and measured was propene. The mathematical relations used for the calculation of adsorption-desorption rate constants, surface reaction rate constants and adsorption equilibrium constants for the reactant cyclohexane are different from previously studied catalytic reactions, owing to the different experimental arrangement for feeding the catalytic bed. The diffusion bands obtained experimentally for reactant or product are described by the sum of two or three exponential functions of time, respectively. From the exponential coefficients of time and the pre-exponential factors, all determined by simple PC programs, the above kinetic parameters are calculated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267960
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Gas chromatography on a self-associating component of a binary phase. Retention model by formal analogy with conductance of electrolytes in dilute solution (1995)
    Springer
    Chromatographia 41 (1995), S. 221-226 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Binary stationary phase ; Self-associating phase components ; Retention model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The dependence of specific retention by a binary stationary phase in GC can be expressed as the sum of the products of the specific retention of the pure components times their respective volume fractions. In this study, however, one component has a site, which is not only mainly responsible for the selectivity, but also participates in strong self-association. This requires introduction of a concentration-dependent factor (μx) in the corresponding term of the equation correlating Vg mix x with x. In the GC resolution of N-trifluoroacetyl-amino acid isopropyl esters on a binary phase, N-lauroyl-L-amino t-butyl amide-squalane, data for the values of μx were obtained. Adapting a previously developed LC retention model to the above GC data, an equation was derived for the dependence of μx on the weight fraction (x) of the selector, namely μx=√1/x. This relationship permits calculation of retention volumes on the binary phase for a given x, as well as corresponding resolution coefficients of enantiomeric amino acid derivatives with generally excellent agreement with experiment. The chirality of the system is not relevant to application of the equation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02267959
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Fast headspace analysis with short microcapillary columns (1995)
    Springer
    Chromatographia 41 (1995), S. 419-423 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Headspace analysis ; Microcapillary columns ; Short columns ; Volatile compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new method of analysis using headspace gas chromatography with microcapillary columns is proposed. Small diameter (50 μm I.D.) fused-silica capillary columns with non-extractable SE-54 and PS-255 polysiloxane stationary phases were used for the analysis of low boiling organic compounds. The small diameter columns possess the usual very high efficiency so that the method can be employed for the headspace analysis of complex mixtures. The use of short microcolumns reduces the analysis times in comparison to conventional capillary columns. Good performances were obtained in the analysis of volatile compounds in some lemon essential oil, perfumes, and water samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02318616
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Capillary gas chromatography of aromatic bicyclic and tricyclic spiro ketones (1995)
    Springer
    Chromatographia 41 (1995), S. 594-598 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Capillary column ; Bicyclic spiro ketones ; Tricyclic spiro ketones ; Retention index at different temperatures ; Retention vs stationary phase polarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The separation of some aromatic bicyclic and tricyclic spiro ketones on fused silica capillary columns coated with polydimethylsiloxane, cyanopropylmethylsiloxane and poly(ethylene glycol) stationary phases was investigated. Retention indices were determined at two temperatures in order to enable understanding of the compounds' chromatographic behaviour. The respective standard deviation values were 0.8, 0.5 and 0.3 index units. The influence of the polarity of the stationary phases on the chromatographic retention of these cyclic spiro ketones is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02269725
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Characterisation of paint layers in Chinese archaelogical relics by pyrolysis-GC-MS (1999)
    Springer
    Chromatographia 49 (1999), S. 268-272 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Mass spectrometry ; Analytical pyrolysis ; Chinese art objects ; Mercury analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A few samples of polychrome Chinese archaeological objects of art have undergone analytical pyrolysis coupled with GC-MS to evaluated the possibility of contemporary characterization of the pigments as well as the organic media used. The red pigment cinnabar (HgS) is easily media used. The red pigment cinnabar (HgS) is easily detected, whereas in the case of organic components positive results are only found where the matrices are resistant to archaeological environmental conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467555
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Polybutadiene-coated zirconia packing materials in solvating gas chromatography using carbon dioxide as mobile phase (1999)
    Springer
    Chromatographia 49 (1999), S. 431-435 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Supercritical fluid chromatography ; Solvating gas chromatography ; Polybutadiene coated zirconia ; CO2 mobile phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In this paper, practical considerations of column efficiency, separation speed, thermal stability, and column polarity of capillary columns packed with polybutadiene-coated zirconia were investigated under solvating gas chromatography (SGC) conditions using carbon dioxide as mobile phase. When compared with results obtained from conventional porous octadecyl obtained from conventional porous octadecyl bonded silica (ODS) particles, PBD-zirconia particles produced greater change in mobile phase linear velocity with pressure than conventional ODS particles under the same conditions. The maximum plate number per second (Nt) obtained with a 30 cm PBD-zirconia column was approximately 1.5 times higher than that obtained with an ODS column at 100 °C. Therefore, the PBD-zirconia phase is more suitable for fast separations than conventional ODS particles in SGC. Maximum plate numbers per meter of 76,900 and 63,300 were obtained using a 57 cm×250 μm i.d. fused silica capillary column packed with 3 μm PBD-zirconia at 50 °C and 100 °C, respectively. The PBD-zirconia phase was stable at temperatures up to 320 °C under SGC conditions using carbon dioxide as mobile phase. Polarizable aromatic compounds and low molecular weight ketones and aldehydes were eluted with symmetrical peaks from a 10 cm column packed with 3 μm PBD-zirconia. Zirconia phases with greater inertness are required for the analysis of more polar compounds by SGC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467619
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Estimation of retention times of homologous series in temperature programmed gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 509-512 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Homologous series ; Retention times
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary It is shown how to estimate the retention times of homologous series members in linear temperature programmed gas chromatography with the aid of a spread-sheet. Both the ease of estimation and the accuracy of the estimation depend on whether the homologue is eluted during the rising portion of the temperature program or the hold time at the end, and also on whether the homologous series is eluted from one injection or a number of injections. When all members of the series elute in the one chromatographic run the percentage standard deviation of the predicted retention times from the experimental retention times is 0.1. When members of the series elute in different chromatographic runs, the percentage standard deviation of predicted times from experimental times is 0.6, compared with an experimental percentage standard deviation for replicates of 0.5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467750
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Efficiency of direct solid-phase microextraction from water-comparison of different fibre types including a new C8-coating (1999)
    Springer
    Chromatographia 49 (1999), S. 686-690 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid-phase microextraction ; Fibre coating ; Volatile organic compounds ; Semi-volatile organic compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The efficiency of direct solid-phase microextraction (SPME) was determined for 27 selected volatile and semivolatile organic compounds (BTEX, chloro- and bromobenzenes, chlorinated pesticides and PCBs). The fibres used were 7μm polydimethylsiloxane (PDMS), 30μm PDMS, 100μm PDMS, 65μm PDMS-divinylbenzene, 85μm polyacrylate, 65μm Carbowax-divinylbenzene, 75μm Carboxen-PDMS and a new 65μm C8 fibre. Extraction yields for these compounds were calculated under standardised conditions: 75μm Carboxen-PDMS was found to be the most efficient fibre for compounds with low boiling points. Although 65μm C8 can be used for extraction of all compounds studied, in no one case is it the most effective coating. 100μm PDMS and the more polar coatings can be used for a broad range of compounds, whereas application of 7μm and 30μm PDMS cannot be recommended. Inter-fibre comparison revealed significant differences between three different Carboxen-PDMS fibres. The results enable suitable coatings to be chosen for each of the 27 compounds and for substances with similar properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02466913
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    The GC determination of cisplatin as platinum(II) from pharmaceutical preparations and blood sample of cancer patients (1999)
    Springer
    Chromatographia 49 (1999), S. 249-252 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Cisplatin determination ; Blood analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A capillary gas chromatographic method is described for the determination of cisplatin based on the complexation of platinum(II) with bis(isovalerylacetone) ethylenediimine (H2IVA2en) and extraction in chloroform. The chromatography was carried out on a BP1 or a BP5 column with an FID. Copper(II), nickel (II) and palladium(II) separated completely and did not affect the determination of platinum(II). The method was applied of the determination of cisplatin in a pharmaceutical preparation and blood samples of cancer patients after infusion of cisplatin. The amounts of cisplatin in blood were found to be within 246–283 ng mL−1 with a C.V. of 2.35–4.26%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467551
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Transition metal complex stationary phases for the CGC analysis of ethers, thioethers and ketones (1999)
    Springer
    Chromatographia 49 (1999), S. 273-280 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Complexation stationary phases ; Bonding metal complexes ; Capillary columns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The use of polysiloxanes with cyano or thiol groups as stationary phases for complexation gas chromatography is discussed. The polymers were obtained via polycondensation followed by polymerisation of the corresponding dichloro- or dimethoxy-silanes. Both the phases were modified by bonding transition metal chlorides with were modified by bonding transition metal chlorides with cyano (CuCl2 or CoCl2) and thiol groups (NiCl2 or CoCl2). The phases were examined in order to determine their application to the analysis of ethers, thioethers and ketones. Due to the presence of lone electron pairs on oxygen or sulphur atoms, the compounds should be capable of specific interacting with the electron-withdrawing centre of the liquid stationary phases. A number of retention parameters (retention indices, molecular retention indices and specific retention volume) were determined, which allowed characterisation of specific interactions between the bonded metal and the compound analysed. The results also enabled assessment of the influence of the structure of the compounds on their retention. The measurements were also carried out for the phases with free SH and CN groups as reference phases. The work demonstrates that the phases obtained may be useful for effective separations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467556
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Averaging the pressure and flow rate of the carrier gas in a gas chromatographic column (1999)
    Springer
    Chromatographia 49 (1999), S. 449-453 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Average column pressure ; Average column flow ; Specific retention volume ; Distribution coefficient
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A systematic derivation of corresponding equations shows that averaging the pressure and the flow rate of the mobile phase in a gas chromatographic column over the column length and over the time that an unretained component resides in the column, requires the use of three different compressibility correction factors,j 2 1 ,j 3 2 , andj 4 3 . When multiplied by the adjusted retention volume,V R-VM, the Martin and James mobile phase compressibility correction factorj 3 2 , only, produces the value of specific retention volume,V g T , which is connected unambiguously with the thermodynamic phase distribution coefficient,K, of the sorbate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467622
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Solid phase microextraction of volatiles from water using open cap vials (1999)
    Springer
    Chromatographia 49 (1999), S. 513-519 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid phase microextraction ; Open cap vials ; Volatile compounds (BTEX) ; Water matrix
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The testing of open cap vials in headspace solid-phase microextraction combined with capillary gas chromatography is reported. The losses of volatile analytes from such vials were analyzed theoretically and investigated experimentally. The benzene, toluene, ethylbenzene, and xylene isomers spiked in water were used as model compounds. Extraction yields and precision obtained under optimized experimental conditions as exposure time, desorption time and temperature were compared applying vials with open caps or sealed with teflon lined septa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467751
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Synergistic effect of mixed stationary phase in gas chromatography (1999)
    Springer
    Chromatographia 49 (1999), S. 567-571 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Mixed stationary phase ; Calixarenes ; Crown ethers ; Cyclodextrins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Mixed stationary phases containing of 25,27-dibutoxy-5,11,17,23-tetra-tert-butyl-26,28-diundecenyloxy calix [4]arene (C[4]B)+ω-undecylomethyl-18-crown-6 polysiloxane (PSO-11-18-C-6) and C[4]B polysiloxane (PSO-C[4]B)+permethyl-β-cyclodextrin (PM-β-CD) were investigated in capillary gas chromatography. By comparing their selectivity for positional isomers with that of the corresponding individual pure stationary phases, synergistic effects were found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467761
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Gas chromatographic determination of 2-chloro-1-[[4-[(2,6-dichlorophenoxy)methyl]phenyl]methoxy]-4-methoxybenzene (SCH 48973), a potent anti-picornaviral agent, in dog serum (1999)
    Springer
    Chromatographia 49 (1999), S. 575-578 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Electron capture detector ; Anti-picornaviral agent in dog serum ; Enteroviruses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A gas chromatographic assay for the determination of SCH 48973, a potent broad spectrum anti-picornaviral agent, was developed and validated in dog serum. The method involved extraction with organic solvent followed by separation on a capillary column (DB-1) with quantitation by an electron-capture detector. The method was sensitive with a limit of quantitation of 10 ng mL−1. The linearity of the method was satisfactory as indicated by correlation coefficients of 〉0.999 and visual examination of the calibration curves. The method was precise with a coefficient of variation ranging from 2.3 to 13.2% and accurate with a bias ranging from −9.1 to 7.9%. Moreover, SCH 48973 was stable in dog serum after being subjected to three freeze-thaw cycles. The assay was shown to be sensitive, specific, accurate and precise, and reliable for use in pharmacokinetic or toxicokinetic studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467763
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Analysis of organic pollutants in sewage by supercritical fluid extraction (1999)
    Springer
    Chromatographia 49 (1999), S. 399-405 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Solid phase adsorption ; Supercritical fluid extraction ; Sewage ; Organic pollutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Analytical methods have been developed for the determination of organic pollutants of intermediate polarity in sewage. Water samples are first passed through a solid phase adsorption cartridge. The analytes are then extracted from the absorbent with supercritical CO2 into a small volume of trapping solvent. Finally, the extracts are analyzed directly by capillary gas chromatography and gas chromatography-mass spectrometer. The various parameters (pressure, temperature, type and concentration of modifiers, trapping solvent, flow rate and volume of supercritical fluid and equilibrium time) influencing the efficiency of extraction were studied. Extraction efficiencies for the test compounds are 〉70%, and relative standard deviations are 〈4.6% (n=3). The methods established were applied to the analysis of sewage at the Lanzhou Wastewater Treatment Plant, China. 66 organic pollutants were detected, of which 15 compounds appeared in the list of priority pollutants suggested by the US EPA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467613
    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...