ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Gas chromatography
  • Springer  (127)
  • Blackwell Publishing Ltd
  • 1980-1984  (108)
  • 1975-1979  (19)
Collection
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 34 (1983), S. 20-26 
    ISSN: 1570-7458
    Keywords: Dioryctria abietella ; Cone pyralid ; Lepidoptera ; Pyralidae ; Sex pheromone, (Z,E)-9,11-tetradecadienyl acetate ; Single sensillum recordings ; Electroantennography ; Gas chromatography ; Mass spectrometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'analyse en chromatographie gazeuse associée à une détection électroantennographique a montré que l'acétate (Z,E)-9,11-tétradécadiényle (Z,E)-9,11–14:Ac est l'un des composants de la phéromone de Dioryctria abietella Schiff (Lepid.: Pyralidae). Couplage chromatographie en phase gazeuse spectrometrie de masse a montré la présence d'acétate tétradécadiényle avec un spectre de masse et un indice de rétention identiques au Z,E-9,11–14:Ac Un récepteur cellulaire sensible à la fois au Z,E-9,11–14:Ac et à un extrait de la femelle a été identifié sous l'antenne du mâle. Les analyses des antennogrammes et de la cellule isolée ont étayé la caractérisation du composant de la phéromone comme étant Z,E-9,11–14:Ac. Un récepteur cellulaire additionnel sensible à l'acétate (Z.)-9-tétradécadiényle et à l'acétate (Z.E.)-9,12-tétradécadiényle a été trouvé sur l'antenne du mâle, mais il n'était pas activé par l'extrait de la femelle. Sur le terrain Z,E-9,11–14:Ac, présenté seul, attirait des nombres importants de mâles de D. abietella. L'addition de l'acétate (Z)-9-tétradécényle a inhibé l'attraction des mâles par les pièges.
    Notes: Summary Gas chromatographic analyses coupled with electro-antennographic detection indicated that (Z,E)-9,11-tetradecadienyl acetate (Z,E-9, 11–14:Ac) is a pheromone component of the cone pyralid Dioryctria abietella. Gas chromatographic-mass spectrometric analyses confirmed the presence of a tetradecadienyl acetate with mass spectrum and retention index identical to Z,E-9,11–14:Ac. A receptor cell sensitive to both Z,E-9,11–14:Ac and the female extract was identified on the male antenna. An additional receptor cell sensitive to (Z)-9-tetradecenyl acetate and (Z,E)-9,12-tetradecadienyl acetate was found on the male antenna but was not activated by the female extract. In the field Z,E-9,11–14:Ac presented alone attracted significant numbers of male D. abietella. Addition of (Z)-9-tetradecenyl acetate inhibited the attraction of males to traps.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention index calculation ; lg ts=f(C) ; Dead-time ; Complex mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die bisher in der Literatur beschriebenen Verfahren zur Retentionsindex-Bestimmung beruhen auf einem linearen Zusammenhang zwischen dem Logarithmus der Nettoretentionszeit lg ts und der Kohlenstoffzahl C der n-Alkane. Wie genaue Meßwerte für Retentionszeiten zeigen, ist die Funkton lg ts=f(C) nicht streng linear. Die Krümmung des Funktionsbildes bedingt, daß lineare Regressionsmethoden, sowie auch die Methode nach Kovats, es nicht erlauben, extrapolativ sowie über weite Retentionsbereiche interpolativ I-Werte zu berechnen. In dieser Arbeit werden Retentionsindices aufgrund eines kubischen Zusammenhanges zwischen lg ts und der Kohlenstoffzahl ermittelt. Die hierzu notwendige Totzeit tm wird aus den Differenzen der Bruttoretentionszeiten der Referenzhomologen ermittelt.
    Notes: Summary Methods of retention index calculation described in the literature have been based on a linear relationship between the logarithm of the adjusted retention times lg ts and the carbon numbers C of n-alkanes. Exact measurements of the retention times of n-alkanes show that the relationship lg ts=f(C) is in fact not strictly linear. Correct extrapolative or interpolative calculations of retention indices over a wide retention range are therefore impossible when using the original formula as given by Kovats or methods based on a linear regression concept. The method of retention index calculation presented here is based on a cubic relationship between lg ts and carbon number allowing extrapolative or interpolative calculations. The hold-up time (tm) is calculated on the basis of differences of retention times of the reference homologues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 265-270 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Columns: open tubular ; Columns: capillary ; Efficiency ; Mean specific plate number
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new parameter, the mean specific plate number, is proposed for assessing the efficiency of support coated open tubular (SCOT) and wall coated open tubular (WCOT) columns and for comparing the efficiency of different open tubular columns. It has the advantage over most previously used parameters in that it has only a small dependence on the partition ratio and it allows for the column diameter. A graphical presentation is given of the maximum theoretical mean specific plate number as a function of the partition ratio for SCOT columns having a range of relative porous layer thicknesses and for WCOT columns with a range of phase ratios. This presentation permits ready visual comparison of the potential efficiency of different columns and enables a simple evaluation of the percentage utilization of theoretical efficiency from experimentally determined values of the maximum mean specific plate number. For a given column the percentage utilization of theoretical efficiency at optimum average gas velocity and that at optimum practical gas velocity or at a higher average gas velocity are shown to be equal provided that corrections for column pressure drop are made.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 651-660 
    ISSN: 1612-1112
    Keywords: Capillary columns, glass ; Gas chromatography ; Column preparation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Glass capillary column chromatography is the most rapidly growing part of gas chromatography. There are many complex new analytical tasks and they require special capillary columns. Fortunately there is a wide range of column preparation methods available, and they make the preparation of glass capillary columns a more varied job than that of packed columns. In this paper these methods are reviewed and suggestions are given for making task-oriented columns.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1612-1112
    Keywords: Configuration ; Chiral phases ; Gas chromatography ; Isovaline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The D-(resp. R) configuration of isovaline (=2-ethylalanine) was proved for the peptide antibiotics antiamoebin, Tü 165 (CBS 382.62), stilbellin, samarosporin (=emerimicin IV), suzukacillin B (A), trichotoxin A-40 and A-50. This contradicts the previously reported L-configuration for isovaline in antiamoebin and emerimicin IV. The configuration was determined by GC of the N-trifluoroacetyl-isovaline n-propyl ester on glass capillary columns coated with the chiral stationary phase N-propionyl-L-valine tert.-butylamide polysiloxane (Chirasil Val). The D-configuration of the isovaline from trichotoxin A-40 was also established independently using GC of N-pentafluoro-propionyl-isovaline (+)-3-methyl-2-butyl esters on glass capillary columns coated with OV 17.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 601-602 
    ISSN: 1612-1112
    Keywords: Ethanolamines ; Ethylene glycols ; Direct separation ; Gas chromatography ; Short glass capillaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An effective and rapid GC separation of ethanolamines, even in the presence of ethylene glycols, using short glass capillary columns is developed. No preliminary derivatisation of the sample is necessary. The separation is completed in 6 minutes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 143-147 
    ISSN: 1612-1112
    Keywords: Capillary columns ; Gas chromatography ; Retention index ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention index of twenty different homologous series of esters have been determined experimentally on polar (Carbowax 1540) and non-polar (squalane) columns. General equations to calculate retention index have been established by statistical methods. The influence of the length and inductive effect of acid and alcohol chains and the relative position of the carboxylic group are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 285-288 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Porous layer open tubular columns ; Kaolin as support ; Column performance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary PLOT columns have been prepared with kaolin as the liquid phase support. These columns show good efficiency with different stationary phases and good thermal stability with polar phases. The performance of columns is shown by the separation of various mixtures such as fatty acids, phenols and anilines which are of analytical importance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    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
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1612-1112
    Keywords: Teflon capillary columns ; Chemically modified teflon ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The preparation of teflon capillary columns employing direct coating of the stationary phase to the chemically modified teflon surface and the role of the chemically modified teflon in the separation mechanism are described. Two types of contributions from the modified teflon have been observed: nonspecific adsorption of the carbon surface and specific interactions of polar groups in the carbon skeleton. The use of polar liquid phases can eliminate adsorption due to the presence of polar groups in the modified teflon.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 803-807 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Ionization detector ; High frequency discharge ; Specific or no specific detection ; Gas adsorption (by flues)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The response of a high frequency ionization detector according to various parameters: voltage, tuning capacitance, feed-back capacitance, space between the electrodes and direct flux-plasma distance is studied. The characteristic measure of v in accordance to high voltage for various mixtures of carrier gas argon-nitrogen gives a maximum which demonstrates that specific automatic analyses of oxygen, krypton and methane are possible with concentrations in the order of ppb. Complete adsorption of 0.8 ppb of methane by a flue of 120 cm in tube 2×4 mm at 50°C after twentieth recycling is essential.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Ethanolamines ; Ethylene glycols ; Porapak Q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary GC separation of pure ethanolamines as well as mixtures with ethylene glycols, obtained from a real technological process is achived using Porapak Q coated with 15% Carbowax 20M. Symmetrical peaks, satisfactory resolution, and reasonable analysis times are obtained. The proposed method is suitable for a convenient, correct and express routine analysis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Van der Waals' volume ; Polarity of stationary phase ; Retention index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Equations for Retention Index (I) versus Van der Waals, volume (Vw) on squalane are studied for alcohols, carbonyls, esters and ethers. Each equation includes linear and branching substances with different positions of the functional group in the carbon chain. The study is extended to stationary phases with polarities from 4.29 to 91.54 on the Tarjan et al. scale. Variations of the slope and origin ordinate values with the polarity of the stationary phase are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 125-132 
    ISSN: 1612-1112
    Keywords: Capillary columns ; Fast analysis ; Gas chromatography ; Instrumental effects ; Optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The efficiency of fast GC columns depends largely on the quality of the chromatograph. A theoretical and experimental study shows the relative importance of the various phenomena involved and permits the optimization of a GC System. Extremely good performances, exceeding 2,500 plates per second have been routinely obtained.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 351-354 
    ISSN: 1612-1112
    Keywords: Supported catalysts ; Reserved-flow GC ; Drying step ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Application of reversed-flow gas chromatography to study the drying step in the preparation of supported catalysts is proposed. It is demonstrated that this technique can be applied to investigate the kinetic law followed, as well as to obtain kinetic parameters of drying (rate constants, activation energies and frequency factors). Amaterial illustrating this application is γ-Al2O3 impregnated with usual organic solvents (n-C5H12,n-C6H14,n-C7H16, CH3COCH3 and CH3CH2OH). It was found that in all cases above a simple first-order law based onone kind of active site is followed. Moreover, it was observed that the activation energyE a of the drying process increases almost linearly with the relative molecular mass of the solvent, whereas for the same solventE a increases with the amount used. The operation of a kinetic compensation effect suggests “similar” activated complexes of the various solvents used.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Capillary columns ; Fused silica capillaries ; Capillary drawing ; Glass capillaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A compact description is given of a simple and reliable method of drawing flexible fused silica capillary for gas chromatography. Some emphasis is given to the fact that the practices of drawing optical fibres should not be followed too slavishly so this leads to unnecessarily complicated and expensive equipment. Satisfactory capillary column silica tubing can be made with straightfoward extension of the method developed earlier for drawing thick walled capillary. A simple glass/silica hydrogen oxygen diffusion flame bumer is described for fusing the preform tubing at the draw point which is enclosed by a water cooled glass enclosure to trap evaporated silica and maintain the operation under dust free conditions. The uniformity of the capillary diameter is better than 5% which is adequate for most gas chromatographic purposes. The second part of the paper yet to be published will cover the methods developed for coating the capillary both internally and externally.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 567-571 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Helium detector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Four main factors which determine the shape and the polarity of the helium detector signal are discussed. All possible responses of this detector, both in elution and in vacancy chromatography, are presented and special attention is drawn to the intermediate region. The idea of ionization vacancy is introduced for the specific case of two components which are unresolved by the column and to which the detector responds with different sensitivity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 574-575 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Xylenol isomers ; Sugar derivatives as liquid phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Adenosine, guanosine and inosine used as liquid phases in gas chromatography permits the separation of all six xylenol isomers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Polycyclic aromatic hydrocarbons ; Retention index ; Average molecular polarizabilities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A significant correlation has been found between the retention indices of polycyclic aromatic hydrocarbons on non-polar stationary phases and the average molecular polarizabilities of the molecules separated on these phases. Equations have been derived for the determination of the average molecular polarizabilities, directly from the retention indices.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 69-72 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Polynuclear aromatic hydrocarbons ; Retention index ; Vapour pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The retention index of a planar polynuclear aromatic hydrocarbon on the GC phases OV-101, SE-52, and OV-17 is strictly related only to the boiling point, and less closely to the relative molecular mass. The very approximates relation with connectivity index ins only a consequence of the latter. On a nematic lqiuid crystal phase, a variation of activity coefficient, expressed in terms of a shape factor, also influences the retention of PAH.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 269-276 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Detector performance ; Trace analysis ; Catalytic conversion ; Multidimensional gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Relationships are derived describing how the detection limit of a chromatographic system depends on the minimum detectable limit of the detector and the chromatographic parameters such as column length, efficiency, carrier gas flow rate and the capacity factor. Performance data of detectors developed in the last 25 years at the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences are given and a few selected application examples are listed. These include trace analysis by preconcentration and by direct analysis and the utilization of multidimensional gas chromatography with two columns, two detectors, a 12-port valve, and a catalytic conversion reactor.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    ISSN: 1612-1112
    Keywords: Gas chromatography ; C1−C5 Hydrocarbons ; Dimethyl ether
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An analytical GC method was developed which uses a single packed column consisting of three packings in series prepared with the following liquid phases: dimethyl sulfolane, propylene carbonate, and silver nitrate. This system provides satisfactory resolution of mixtures of C1−C5 hydrocarbons and dimethyl ether obtained when converting methanol to gasoline. Due to the high capacity of the column it is possible to inject larger sample amounts permitting trace analysis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1612-1112
    Keywords: Phthalides ; Umbelliferae ; Liquid-solid chromatography ; Gas chromatography ; Ligustilide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A liquid-solid chromatographic pre-fractionation of naturally occurring phthalides has been developed. The LSC was carried out on a column of silica applying a 1–50% gradient elution of diethyl ether (containing 2% methanol) in pentane. The enrichment in the fractions led to better possibilities for a gas chromatographic separation and isolation allowing further studies by spectroscopic methods. Ligustilide may easily isomerize during GC as a result of ageing of the column.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 30-32 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Arsenic ; Inorganic materials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the quantitative chlorination and extraction of arsenic as arsenic trichloride from a number of alloys. The conditions for the quantitative gas chromatographic measurement of the volatile chloride have been studied. The proposed method for inorganic materials is very fast giving results within 10 min; sensitive, 1.5·10−13 g As can be detected, simple and accurate. At the ng level of As the error is about 20% with a standard deviation less than 20%, and at the 10pg level the error is about 36% with a standard deviation of 44%.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 765-768 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Preparative scale chromatography ; Capacity ; Dual-stage separation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The capacity of different versions of single- and dual-stage separation of mixtures on a preparative scale is considered. It has been shown that dual-stage separation with intermediate condensation considerably enhances the capacity of the installation as compared with a single-stage process.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 117-124 
    ISSN: 1612-1112
    Keywords: Various packed GC column ; Gas chromatography ; Porous layer beads ; GC/MS analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Theoretical comparisons of various packed GC column types are presented with respect to analysis time, efficiency, sample dilution, and sample capacity for a given maximum inlet pressure. In particular, totally porous particles, porous layer beads, and glass beads are compared with one another. It is shown that 30 μm porous layer beads offer a useful compromise between analysis time and plate count with relatively good sample capacity. Moreover, when using 1 mm i.d. columns (microbore), outlet flow rates that are reasonable for direct coupling to magnetic sector mass spectrometers are achieved making these columns suitable for GC/MS. Using 30 μm Zipax porous layer beads, columns yielding 8,000 to 10,000 plates/meter have been produced with inlet pressures of 13 to 26 atm. A simple modification of the injection port converts the maximum inlet pressure of a commercial gas chromatograph to 26 atm. With such pressures, columns in excess of 20,000 plates can be achieved. Chromatograms are presented illustrating the promise of these microbore columns for GC and GC/MS analysis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 245-248 
    ISSN: 1612-1112
    Keywords: Chromatoscopy ; Gas chromatography ; Graphitized carbon black ; Molecular structure and retention ; Aromatic hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A molecular-statistical calculation of the retention volumes at zero sample size on graphitized thermal carbon black is carried out for quasi-rigid molecules of fluorene, indene, 1-methylindene, 2-methylindene and three dimethylindenes. A reasonable agreement is observed between the calculated and the available experimental gas chromatographic data. The potential barrier to internal rotation and the torsional angle in styrene molecules are estimated by comparing theoretically calculated and measured retention volumes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Silicone liquid phases ; Oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The on-column oxidation of apolar and polar silicones used as gas chromatographic stationary phases is investigated. Even at 225° the effects of oxidation are found to be slight. Of the materials investigated the methylphenylsilicones are the most stable.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1612-1112
    Keywords: Glass capillary ; Gas chromatography ; Methyl chloroacetates ; Methyl chloropropanoates ; Methyl chlorobutanoates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The gas chromatography of all chlorinated methyl acetates, methyl propanoates and methyl mono- and dichlorobutanoates has been studied on Carbowax 20M and SE-30 glass capillary columns under various running conditions. The order of elution on a non-polar column was largely determined by the boiling point of esters, whereas on a polar column it was much influenced by the structure of compounds. Complete separation of the combined mixture of all 27 compounds could not be achieved, however, methyl 3,3-dichlorobutanoate was the only ester overlapped on both columns in spite of the various column temperatures used. The best separation of the mixture was on Carbowax 20M with a temperature program from 50°C at 8°C/min, isothermal running conditions leading either to poor separation of volatile components or long analysis time and broad peaks of higher chlorinated esters. The relative retention times for compounds at the various column temperatures are given and the retention order on a polar and on a non-polar column discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 517-520 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Carbon-silica adsorbents ; n-Octadecanol film ; Phase transitions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The properties of the n-octadecanol film on carbon-silica adsorbent (Carbosil) were investigated. It was found that n-octadecanol forms an oriented film on the Carbosil's surface. If the surface of the basic silica gel is not completely covered with carbon, then the phase transition takes place in this film at a temperature higher than the melting temperature of n-octadecanol. One may distinguish two forms of this film, characterised by the different structures and the temperatures of the phase transitions. The first exists on the surface of silica gel unblocked by carbon. This part of the film is a monolayer, in which the alcohol molecules are vertically oriented. The solid compact-liquid expanded type phase transition at the well-defined temperature occurs in this film. In the second part of the film formed on the carbon surface, there is a multilayer of n-octadecanol. Its molecules are probably parallely oriented in relationship to the adsorbent surface. This film desintegrates progressively when the temperature increase. Maximum temperature of this phase transition is lower than the temperature of its analogue on pure silica gel surface.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 546-558 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Capillary columns ; Quantitative analysis ; Sample inlet systems ; High-speed analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The attainment of precise quatitative analytical data using open-tubular (capillary) columns in standard, commercially available gas chromatographic instrumentation is demonstrated. Key elements in the design and proper utilization of the instrumentation are discussed. The function of the various sample introduction systems is elaborated and their quantitative performance demonstrated. The extra-column contribution to band-spreading is determined and the resultant data is used assessing the suitability of commercial instrumentation for highspeed capillary gas chromatography. The quantitative analysis of a sample containing some eleven components in less than thirty seconds is shown.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Crystal hydrates as stationary phases ; Mobile Phases containing water ; Selective retentions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The use of crystallohydrates, crystallohydrate solutions and melts as stationary phases in gas chromatography has been proposed. Crystallohydrates have been shown to display high selectivity in the separation of polar organic compounds when use is made of water vapours as the mobile phase. Some aspects of gas-liquid chromatography in water vapours and with the stationary phase comprising crystallohydrates have been studied, and the preliminary results obtained point to the desirability of further progress in this field.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 201-203 
    ISSN: 1612-1112
    Keywords: Phenols ; Whisky ; Gas chromatography ; Aroma compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Twelve volatile phenols were identified in whisky by combined gas chromatography-mass spectrometry. Of these phenols 2,4-dimethylphenol was found for the first time in the aroma of whisky. The content of phenol, o-, m-, and p-cresol, guaiacol, p-ethylphenol, p-ethylguaiacol and eugenol in whiskies originating from different countries was determined by gas chromatography as their 2,4-dinitrophenyl ethers using electron capture detection. The results show that Scotch whiskies differ from others in the content of o-, m-, and p-cresol. The odour threshold values of phenols studied were determined in a 10% (v/v) ethanol-water mixture and in some cases also in the whiskies. Cresols have been found to make contribution to the aroma of Scotch whisky.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 26-31 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Ionization detectors ; Gaia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper is an account of the development of the gaia hypothesis as seen through the eyes of a gas chromatographer. Gaia is a radical notion about the Earth which postulates the climate and chemical composition to be regulated at an optimum by and for life. Gas chromatography played an important role in the gathering of evidence for the hypothesis but most significantly the art of inventing detectors lead to the developement of a planetary life detector through which gaia was revealed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 282-285 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Naphtha analysis ; Gasoline analysis ; Hydrocarbon type analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Two different gas chromatographic methods are used for the determination of hydrocarbon type distribution in naphtha and gasoline samples with final boiling points up to 275 °C. The methods are based either on a single capillary column or on a valve-switched packed column system. Both methods give extensive information on paraffins, olefins, naphthenes and aromatics in total as well as by carbon-number. In each case the analysis is fully automated with a computer controlling the entire analysis from injection to results presentation. The advantages and limitations of both methods are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 322-324 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Graphitized carbon black supports ; Determination of hydroxyacids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Acid-washed graphitized carbon black (Carbopakc B) modified with trimesic adic and PEG 20M has proved to be effective for quantitative analysis of underivatized low molecular weight hydroxyacids. Calibration data revealed good linear relationships between relative peak area and concentration for lactic and 3-hydroxybutyric acids down to 0.05 mmol/l. The packing material was suitable for the analysis of aqueous solutions of hydroxyacids as it is tolerant to injections of water over a prolonged period of use. The GC system developed has been applied to the analysis of some hydroxyacids of biomedical interest in blood plasma and lactic acid contained in wine and beer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Modified thermal energy analyzer ; Selective detection of nitrogen compounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A modification to the TEATM Analyzer is described, which allows it to be used as a highly selective GC detector for nitrogen compounds as well as for N-nitrosamines and nitro compounds. The modified Analyzer is as sensitive as the AFID, but has a much higher selectivity towards nitrogen compounds than the AFID. Its response appears to be molar, with an output that is dependent only on the number of nitrogen atoms present. The performance of the modified Analyzer for the analysis of ammonia, amines,N-nitrosamines, nitriles and organonitro compounds is reported and discussed, as is its application to the detection of these compounds in bacon and beer samples.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 33-36 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Preparative scale chromatography ; Capacity ; Dual-step separation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The capacity of dual-step preparative chromatographic separation systems is considered. It is shown that dualstep separation makes it possible to enhance the capacity of preparative installations as compared with single- and dual-stage purification of the compounds.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 44-46 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Natural gas analysis ; Poropak N
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple gas chromatographic method is described for the rapid analysis of natural gas using thermal conductivity detectors and programmed-temperature operation of a single Poropak N column. The method permits the determination of nitrogen, carbon dioxide and hydrocarbons containing one to seven carbon atoms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 553-559 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open-tubular (capillary) columns ; Immobilized liquid phases ; Thick-film columns ; Diffusion coefficients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The influence of the liquid phase film thickness in open-tubular (capillary) columns on the individual resistance-to-mass-transfer terms and on the overall column efficiency is examined from the theoretical point of view. Methods for the calculation of the diffusion coefficients are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open-tubular (capillary) columns ; Immobilized liquid phases ; Thick-film columns ; GC-FTIR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The performance of a column prepared with an immobilized (chemically bonded) methylsilicone phase having a film thickness of 5μm is investigated in detail. Due to their high sample capacity, such columns are particularly useful when directly coupling gas chromatography with spectroscopic techniques such as Fourier-transform infrared spectroscopy. Thick-film columns can even be used with thermal conductivity detectors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 600-604 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention index ; Alkyl benzenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The additivity concept in the retention index system of Kovats has been examined for a series ofn-alkylbenzenes and theiro- andp-monosubstituted nitro-, amino-, and chloro-derivatives. Anomalous behaviour is exhibited by the first three members of the series on both polar and non-polar stationary phases. For addition of a methylene group ton-propylbenzene or ap-substituted derivative, it is found that the retention increment, Δl CH2, approaches 100 units. However, the strong inductive effect of the group in the ortho position and the steric effects apparent in ano-substituted alkylbenzene lead to large variations of retention increment upon addition of-CH2-to the alkyl chain. A study ofn-alkylbenzene retention on Apiezon L and Carbowax 20M over a wide range of temperatures has verified the linearity of the retention increment with temperature and has revealed that this gradient increases with increasing carbon side-chain length for the first few members of the series, thereafter becoming constant. Functional retention increments, Δlx, for substitution of nitro-, amino- and chloro-groups into the benzene ring are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 691-692 
    ISSN: 1612-1112
    Keywords: Dichlorophenol isomers ; Sodium benzenesulfonate ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary It is difficult to separate all the dichlorophenol isomers as free phenols by gas-liquid chromatography. However they were effectively separated on 4,4′-dimethoxyazoxybenzene (liquid crystal), and all the isomers were separated appreciably well on sodium 1-naphthalenesulfonate, 2-naphthalenesulfonate and dodecylbenzenesulfonate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 65-69 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Oxygenates ; Fused-silica capillary columns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method of analysing gasolines that contain oxygenates has been developed. The method uses a single fusedsilica capillary column and gives quantitative data for the oxygenates and the hydrocarbons in one analysis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Trace analysis ; GC-concentration ; Enrichment factor ; Theoretical evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Based on gas chromatographic retention data obtained on a given adsorbent and at a given trap efficiency at different temperatures new equations are proposed for the evaluation of the enrichment factor. These equations are suitable under various preconcentration conditions such as: equilibrium saturation, complete trapping and permissible losses. Compared to known expressions for the evaluation of the enrichment factor the equations suggested consider the band broadening of the impurity in a trap causing a loss of the substance at the adsorption stage and dilution of the sample during desorption when the desorbed impurities are directed into the gas chromatographic column without intermediate freezing out in an graphic column without intermediate freezing out in an empty tube. The new equations may be used to select the optimum preconcentration conditions providing the necessary sensitivity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 191-194 
    ISSN: 1612-1112
    Keywords: Thermal treatment of MgO and MgCO3 ; Adsorption properties ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The changes in the chromatographic properties of MgO and MgCO3 due to thermal treatment was investigated. The experimental results show that thermally treated MgO and MgCO3 can be used as stationary phase for the gas-adsorption chromatography of hydrocarbon mixtures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1612-1112
    Keywords: Esterification in aqueous solution ; n-Butyl esters of fatty acids ; Gas chromatography ; Fatty acid analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The esterification of C1−C8 fatty acid in aqueous solutions and in the presence of sulfuric or hydrochloric acid and with n-butanol is described. It has been established that the esterification can be used for the quantitative determination of these fatty acids in the concentration ratio range of [H2O]/[n-BuOH]=0.01–5.3. In the concentration ratio range of 0.01–0.8 the water present does not interfere. In the concentration range of above 0.8 anhydrous sodium sulfate is used for binding the water, in the amount of [Na2SO4.anh.]/[H2O]≥0.2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 472-476 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid stationary phase ; Liquid phase bleeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The theory of the evaporation of the liquid stationary phase is elaborated and experimentally verified. On the basis of this theory the role played by the losses in the amount of liquid phase present is quantitatively determined. General techniques are examined which minimize the losses; these techniques are based on saturating the incoming carrier gas with liquid phase vapours and raising the pressure of the carrier gas in the column, e.g. by connecting a capillary to the column outlet in order to offer resistance to the gas flow. The application of these techniques ensures stable performance of the gas chromatographic columns using a volatile liquid phase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 1612-1112
    Keywords: Esterification in aqueous solution ; iso butyl esters of C1–C20 fatty acids ; Gas chromatography ; Fatty acid analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary C1–C20 carboxylic acids have been esterified in aqueous solutions with i-butanol. Gas chromatographic analyses have been performed from a single chromatogram. It has been established that esterification in the concentration range of [H2O]/[i-BuOH]=0.01–10.3 can be utilized for the quantitative determination of these carboxylic acids. The presence of water does not interfere in the range of [H2O]/[i-BuOH]=0.01–1.03. In the cases of [H2O]/[i-BuOH]〉1.03, anhydrous sodium sulfate has been used for binding the water, in an amount of [Na2SO4]anh./[H2O]≥0.2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Cross-linked Stationary phase ; Immobilized Stationary phase ; Packed columns ; Trapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A coating of silicone SE-54 on Chromosorb W has been converted to an analytically stable, immobilized stationary phase layer by cross-linking with an organic peroxide. Up to 10% by weight has been applied in this manner. Excellent high temperature qualities are exhibited, such as low bleeding and good base line stability, during typical analyses. Poly (2,6-dimethyl-p-phenylene oxide) has also been crosslinked as a surface coating on Chromosorb W with an organic peroxide. From 3 to 4% by weight has been immobilized in this way. The resultant packing material, following high temperature conditioning, has been examined for use as an adsorbent of trace substances, similar to the applications to which such adsorbents as Tenax GC have commonly been applied, e.g. trace analysis of air. It appears to exhibit satisfactory properties for this analytical purpose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 21-22 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Isopropylidene-glucose ; Glucose ; GC of TMS-derivatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper describes the gas chromatographic separation of the mixture of di- and mono-O-isopropylidene-D-glucose and D-glucose as their trimethylsilyl derivatives. The use of OV-101 as liquid phase provides a complete separation for the all components in the mixture. Quantative analysis was performed using xylitol as the internal standard for di- and mono-O-isopropylidene-D-glucose, and sorbitol as the internal standard for α-and β-glucose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Nuclear magnetic resonance ; Terpenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A procedure is described for recording1H NMR spectra of flowing gaseous GC fractions boiling as high as 200°C. The line width of the signals in the NMR spectra is smaller than 2.2Hz.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 556-559 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid chromatography ; Tetramethrin ; Residues
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the analysis of tetramethrin aqueous formulation and residues of tetramethrin on woolen cloth. The samples were extracted with acetonitrile and partitioned with benzene. Interferences were removed by liquid column chromatography with acid alumina and eluted with 10% ethyl acetate-hexane. Analysis was by gas chromatography with a 10% UCW98 (methylsilicone) column. Detection was made with the flame ionization detector to avoid the repeated dilutions necessary with use of the electron capture detector.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention index ; Electric parameters ; Physico-chemical relationships ; Structure-retention study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A new equation is derived relating the retention index to the molecular polarizabilities, ionization potentials and permanent dipole moments of the stationary phase and the solute. Various implications of this equation to quantitative structure-retention relationships are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 1612-1112
    Keywords: Aldehydes and ketones ; 2,4-dinitrophenylhydrazine-coated silica gel ; Gas chromatography ; Column liquid chromatography ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary After a brief review of several methods described in the literature this paper discusses air-sampling on 2,4-dinitrophenylhydrazine-coated silica gel and identification requirements for aldehydes and ketones most commonly found in industrial pollution. Quantitative analysis of formaldehyde and acetaldehyde either by GC or by HPLC techniques is established using a dynamic system producing test atmospheres and compared with the usual colorimetric determinations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 665-671 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention index ; Multiple correlation ; Molecular properties ; Prediction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Ein auf der linearen, multiplen Korrelation basierendes Verfahren wird vorgestellt, das es gestattet, den Retentionsindex von Substanzen in der gaschromatographischen Trennung aus einem Satz Säulenkonstanten und drei bis vier Substanzeigenschaften zu berechnen. Der Fehler der Berechnung liegt unter 2%. Der Ansatz wurde für isothermes und temperaturprogrammiertes Arbeiten getestet.
    Notes: Summary A method based on linear multiple correlation is introduced allowing the calculation of gas chromatographic retention indices from a set of column constants and three to four physical properties of the solute. The error is less than 2%. The formulation has been tested for isothermal and temperature programmed working conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Porous polymer supports ; Retention behaviour-effect of support
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The gas chromatographic behaviour of a series of compounds of different polarity on columns of Ethofat 60/25 on Chromosorb P HMDS (an inactive support) and Chromosorb 101 (an active support) was investigated. To observe how the support influences the chromatographic process, we separated the contribution to the retention volume of the interaction phenomena associated with the stationary phase, the solid support and the corresponding interfaces. In some cases the Chromosorb 101 exerts an influence on the process even with high percentages (〉10%) of stationary phase. The values of the experimental partition constants of a series of compounds and the factors that contribute to adsorption on these columns are calculated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 733-736 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Gas volume, influence of ; Preconcentration ; Wine headspace analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Examination was made of the changes in composition of aroma volatiles trapped on Chromosorb 105 during dynamic headspace sampling of aged wine. Collections from different gas volumes were analysed and a subsequent collection made. It was demonstrated that analyses of headspace collections containing reduced quantities of the more volatile and more, hydrophobic compounds could aid in the identification and quantitative determination of alcoholic beverage components.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 1612-1112
    Keywords: Inclusion compound ; Urea-cetylalcohol adduct ; Gas chromatography ; Clathration process ; Phase changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Phase changes in urea-cetyl alcohol inclusion compounds prepared by various methods were monitored gas chromatographically. The decomposition temperature interval and the presence of the free components could be found from the temperature dependence of the retention data. Study of the clathration process yielded facts that can be used in the preparation of this type of inclusion compound.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 533-538 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Sorbents: liquid phases, supports, adsorbents ; Thermodynamical classification ; Polarity and selectivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Equations modifying Rohrschneider's relationship between ΔI and thermodynamical characteristics values are derived. Polarity in chromatography is discussed as a possibility of stationary phases or absorbents to enter into intermolecular interactions and is determined on the basis of the partial molar free energies of solution (ΔG) of six test substances. A simple method for the calculation of stationary phase polarity in terms of ΔG from retention indices and McReynolds constants is given. Equations are presented for the calculation of stationary phase selectivity utilizing ΔG data tabulated for selected test substances. The thermodynamical basis of selecting a reference phase for a unified system expressing the selectivity of stationary phases which can also be applied for adsorbents is suggested. The energy equivalent to an index unit, ΔGi.u., is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 61-67 
    ISSN: 1612-1112
    Keywords: Optimization ; Carrier gas velocity ; Gas chromatography ; Influence of temperature on optimum velocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Zusammenfassung Die Wahl der mittleren, linearen Trägergasgeschwindigkeit bei der Analyse von Mehrkomponentengemischen unter isothermen und temperaturprogrammierten Bedingungen wird diskutiert. Es wird gezeigt, daß stets eine Trägergasgeschwindigkeit gewählt werden sollte, die mindestens gleich, besser jedoch höher ist, als die optimale Gasgeschwindigkeit für den ersten Peak, gemessen bei der Starttemperatur (Temperaturprogramm) oder bei der eingestellten Ofentemperatur (isotherme Fahrweise).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 686-692 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Micropacked columns in GC ; Microparticles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Porous silica microparticles designed for modern liquid chromatography have proven effective in gas chromatography. Columns of 35–50 cm gave plate heights as low as 3.3 particle diameters and speeds of 2400 theoretical plates per second or 500 effective theoretical plates per second. Inlet pressures up to 70 atmospheres were required using hydrogen as carrier gas. The particles as received were too retentive for fast chromatography and gave asymmetric peaks. A coating of fluorosilicone oil overcame both problems. Other coatings were less effective. Bonded phases proved less satisfactory on both counts and also gave substantially less efficient columns and greater flow resistance. Column efficiency and flow resistance were sharply dependent on physical properties of the particles. The most efficient packing was clearly spherical particles of 5–10 μm diameter with narrow size distribution, pore diamters about 50 nm, BET surface areas of 25–50 m2/g and surfaces modified with trifluoropropyl silicone. A six-component hydrocarbon sample was separated in 33 s with a resolution of 4 for the most difficult pair and in 2.6 s with a minimal resolution. Performance was limited by end effects and by available pressure so that much better performance can be expected from longer columns and higher pressures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 752-754 
    ISSN: 1612-1112
    Keywords: Xylenol isomers ; Gas chromatography ; Polyols and polyethers as stationary phase ; Hydrogen bonding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Xylenol isomers can be resolved on most polyols (sugars or sugar alcohols) and polyethers (polyethylene glycol or polypropylene glycol) with hydrogen-bonding interaction. They are separated on vinical polyols which have more hydroxy hydrogen than tetrol, and even on vicinal triol when its hydroxy hydrogen is acidic (stronger proton donor). The stronger is the hydrogen bonding interaction between xylenols and the liquid phase, the better is the separation of 2,4- and 2,5-xylenol, and the poorer the separation of 2,4-and 2,3-xylenol.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 19-22 
    ISSN: 1612-1112
    Keywords: Teflon columns ; Chemically modified teflon ; Gas chromatography ; Capillary columns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Wall-coated open tubular columns prepared from chemically modified teflon tubing have been developed for gas chromatography. Chemical reaction of the inner walls of teflon tubing allows bonding of an adhesive layer on which a variety of stationary phaes can be coated. Test mixtures of alkanes and alcohols were used to investigate the chromatographic properties of these columns and the stability and mixing of the adhesive and stationary phae layers. the results in dicate that mixing of the layers is negligible and that the column is stable for a long period of time.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 55-66 
    ISSN: 1612-1112
    Keywords: Capillary columns, glass ; Gas chromatography ; Column preparation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Kapillar-Gas-Chromatographie ist heute das sich am stärksten entwickelnde Gebiet der Gas-Chromatographie. Es gibt viele komplexe, neue Fragestellungen in der Analytik, welche den Einsatz spezieller Kapillarsäulen erfordem. Glücklicherweise gibt es aber auch eine große Zahl von Herstellungsverfahren für Kapillarsäulen, welche — noch mehr als bei der Herstellung von gepackten Säulen — eine Anpassung an die gestellten Aufgaben ermöglichen. In diesem Artikel werden die Herstellungsverfahren für Kapillarsäulen zusammengestellt und Anregungen gegeben, wie aufgaben-orientierte Säulen erreicht werden.
    Notes: Summary Glass capillary column chromatography is the most rapidly growing part of gas chromatography. There are many complex new analytical tasks and they require special capillary columns, Fortunately there is a wide range of column preparation methods available, and they make the preparation of glass capillary columns a more varied job than that of packed columns. In this paper these methods are reviewed and suggestions are given for making task-oriented columns.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 89-94 
    ISSN: 1612-1112
    Keywords: Determination of HCl ; Derivatization ; Trace analysis ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung In der vorliegenden Arbeit wird die Möglichkeit untersucht, kleine Mengen HCl durch derivatisierung mit 7-Oxabicyclo-(4.1.0)-heptan und anschließendem gas-chromatographischen Nachweis des Reaktionsproduktes 2-Chlorcyclohexanol zu bestimmen. Die Nachweisgrenze für das Produkt der Derivatisierung (2-Chlorcyclohexanol) entspricht 2 pg HCl. Durch verschiedene Probleme, die im Rahmen dieser Arbeit diskutiert werden, wird diese Nachweisgrenze in der Praxis nicht erreicht. Es zeigt sich jedoch, daß HCl-Konzentrationen im Bereich von ppm (bzw. HCl-Mengen〈1 μg) ohne weiteres zu bestimmen sind. Die Möglichkeiten dieser Analysenmethode werden diskutiert.
    Notes: Summary This paper the possibility of determining small quantities of HCl by derivatization with 7-oxabicyclo-(4.1.0)-heptane and subsequent gas chromatographic identification of the reaction product 2-chlorocyclohexanol is examined. The detection limit for the derivative (2-chlorocyclohexanol) is equivalent to 2 pg HCl. On account of various problems, discussed in the paper, this detection limit is not achieved in practice. It is nevertheless apparent that concentrations of HCl in the ppm-region (quantities of HCl〈1 μg) can be determined without difficulty. The scope for this method of analysis is disscussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 625-630 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Open-tubular (capillary) columns ; Comparison of liquid phases ; Influence of temperature ; Retention index data
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The influence of temperature and liquid phase film thickness of open-tubular (capillary) columns on the retention index values of hydrocarbons on methylsilicone liquid phases is discussed. Data obtained on methylsilicones and squalane are compared. Retention index values of 43 hydrocarbons between 40 and 70 °C on OV-101 liquid phase are listed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 583-586 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Clinical analysis ; Meningitis detection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Gas liquid chromatography was performed on cerebrospinal fluid from cases of purulent meningitis, and control subject. A relatively constant pattern of peaks was obtained in all samples. Four constant peaks in the chromatogram frequently showed a significant increase in purulent meningitis but not in aseptic meningitis or control cases. There was a gradual return to normal levels during clinical improvement, usually within 5–6 days of appropriate therapy. In one case of recurrent meningitis, an increase in the peaks was noted with relapse. Identification of the compounds represented by these peaks may provide further information regarding diagnosis, prognosis and pathogenesis of meningitis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 180-182 
    ISSN: 1612-1112
    Keywords: Acidic fermentation products ; Characterisation ; Gas chromatography ; Methyl esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A rapid and simple method for the identification of acidic fermentation products is described. Methyl esters of volatile and non-volatile acids are separated on a single chromatographic column. Retention time data for a number of acids are tabulated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 521-524 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention index ; Connectivity index ; Van der Waals' volume ; Alkanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The relationships between retention index and Van der Waals' volume and between retention index and connectivity index have been studied for 58 different alkanes (C1−C9) on squalane. The correlation coefficient for the former is higher than for the latter. From these equations a linear relationship between Van der Waals' volume and connectivity index is obtained which indicates that the two parameters are equivalent. A simple method for calculating the Van der Waals' volume of alkanes is proposed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 98-102 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Rectangular channel ; Efficiency ; Capacity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Gas chromatographic experiments have been performed in a truly rectangular channel with a 60∶1 cross-sectional aspect ratio, constructed according to the field-flow fractionation technology. It is shown that the peak broadening is controlled by the thickness of the channel while the maximum load is determined by the largest cross-sectional dimension. However, even with its elongated configuration, the side walls contribute significantly to the band broadening of solutes with a high diffusivity. Good agreement is found between the experimental plate height data and the recent theoretical calculations of Golay [13] taking into account the side-wall effect.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 241-243 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Detectors ; Flame ionization detector ; History of chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary On the occasion of the 25-year anniversary of its invention, this article summarizes the events which led to the development of the flame ionization detector.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Average molecular polarizability ; Retention index ; Polycyclic aromatic hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The Kováts retention indices of 10 polycyclic aromatic hydrocarbons were determined on SE-30, OV-101, SE-52, OV-7 and OV-17 stationary phases. A significant correlation has been found between the retention indices and the average molecular polarizabilities of the analyzed substances. Equations were derived for the direct determination of the average molecular polarizabilities from the retention index values. The influence of the temperature on this relationship is also indicated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 418-420 
    ISSN: 1612-1112
    Keywords: Separation of metal chelates ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A very good separation of the acetylacetonate of AL-(III), Cr(III) and Co(III) has been obtained by gas chromatography, on a column containing OV-17 silicone oil as the stationary phase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Esterification in aqueous solution ; n-Butyl esters of C2−C16 dicarboxylic acids ; Dicarboxylic acid analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary C2−C16 dicarboxylic acids were esterified in aqueous solution in the presence of sulfuric acid. Esterification in water/n-butanol mixtures with mole ratios between 0.02 and 2.53 can be utilized for the quantitative determination of the dicarboxylic acids by gas chromatography. The presence of water does not interfere at water/n-butanol mole ratios below 0.27. For mole ratios above 0.27 anhydrous sodium sulfate has been used for binding the water. The mole ratio range was 0.25–0.75 for anhydrous sodium sulfate/water, and 0.32–1.3 for sulfuric acid/anhydrous sodium sulfate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 202-204 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Polysiloxane stationary phases ; Heat of adsorption ; Heat of solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The changes in the heat of solution of polar compounds and xylene isomers in methylsilicone fluid OV-101 deposited on Chromosorb W AW DMCS were studied. It was shown that the heat of solution increases with an increase of the percentage loading of the OV-101 up to 10%. Solution and adsorption thermodynamic characteristics of the studied system are briefly discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    ISSN: 1432-0878
    Keywords: Preputial glands ; Nude mice ; Ultrastructure ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The preputial glands of male nude (nu/nu) mice were analyzed by a combination of electron microscopy and gas chromatography to determine whether or not they are affected, like developing hairs and nails, by the nu/nu genotype. Results of the analyses revealed no differences between the glands of nude and normal male mice in either their ultrastructural characteristics or lipid secretory products.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 12 (1979), S. 168-170 
    ISSN: 1612-1112
    Keywords: Acid catalyzed esterification ; Amino acids ; Fatty acids ; Gas chromatography ; Isopropyl esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Acid-catalyzed esterification of carboxyl groups with acetyl chloride in isopropanol is investigated. Yields are equivalent to those obtained with reagent prepared conventionally by bubbling gaseous hydrogen chloride into isopropanol. The preparation of the former reagent is less time consuming and no special equipment is needed. The procedure is applicable for other alcohols as well.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 73-84 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Gas hold-up time ; Dead time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The two approaches used for the calculation of the gas hold-up time and thus, the adjusted retention time are outlined, first for the restricted case when the carbon numbers of the three homologues used for the calculation are evenly spaced (c3−c2=c2−c1) and then, for the general case when (c3−c2) differs from (c2−c1). The basic difference in the philosophy of the two approaches is shown.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 1612-1112
    Keywords: Gas chromatography ; On-column abstraction ; Aliphatic aldehydes ; Amine antioxidants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The selective on-column abstraction of aliphatic aldehydes by gas chromatographic stationary phases containing N-iso-propyl N′-phenyl-p-phenylenediamine is described.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 576-578 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Tortuosity factor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The relationship between the obstructive factor γ and velocity was restudied. The dependence of the obstructive factor on velocity was verified. The effects of diffusion coefficient and particle-to-column diameter ratio on the obstructive factor-velocity relationship were investigated. The results are consistent with Hawkes' hypothesis that values of γ at low velocities are averages over tightly packed and loosely packed domains while at high velocities they are weighted in favour of the loosely packed domains where there is more flow.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 648-652 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Gas-liquid adsorption ; Bulk solution ; Mixed stationary phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary It is shown that the blending of some retention effects can make the resolution of complex mixtures on short classical columns as effective as on capillary columns.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 39-40 
    ISSN: 1612-1112
    Keywords: Xylidine isomers ; Heteroaromatic liquid phases ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Nicotinic acid and 1H-benzotriazole appreciably resolved all the xylidine (dimethylaniline) isomers, while benzimidazole, nicotinamide and phthalimide can also separate all the isomers except 2,4- and 2,3-xylidines. The analyses were carried out on supports which were not treated with an alkali.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 203-211 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Quantitative analysis ; Copper oxide converter ; Inorganic gas analysis ; Determination of fluorine and oxygen ; Hydrocarbon analysis ; Wine analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A review of past activities concerning selected industrial analytical problems is given. This includes the following question: preparation of pure gas mixtures to be used for calibration, catalytic conversion of ester and pyridin samples to carbon dioxide and a one-point calibration method using peak heights, both for quantitative analysis, analysis of gas mixtures containing fluorine and inorganic fluorine compounds and the determination of the oxygen and fluorine content of the sample, separation and identification of hydrocarbons in shale oil and petroleum fraction samples, and analysis of wine.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 345-350 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Silica capillaries ; Glass capillaries ; Mixed gum phases ; Polarity and selectivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Mixed phases of Superox 20M and OV-1 can be coated homogeneously on the untreated wall of fused silica capillary columns. Excellent columns with regard to efficiency, inertness and thermal stability can be obtained. (CE〉95% and MAOT≥250°). The polarity and selectivity were ascertained with Rohrschneider-Reynolds probes and a capillary polarity test mixture. The analysis of an essential oil mixture illustrates the possibilities of mixed phases in practical capillary GC.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 421-424 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid sulfur ; McReynolds' constants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The McReynolds' constants for liquid sulfur as a stationary phase in gas-liquid chromatography (GLC) are presented. A simple graphical method of pattern analysis is used to indicate the uniqueness of the sulfur column as compared with other stationary liquid phases characterized by McReynolds. The limitations of using a single factor (as polarity) for the basis for the selection of GLC columns is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 447-451 
    ISSN: 1612-1112
    Keywords: Headspace analysis ; Gas chromatography ; Residual analysis of polyethylene terephthalate ; Acetylene reduction assay ; Ethylene evolution in germinating seed ; Acetaldehyde generation in polyester resin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary New application areas for headspace gas chromatography in agricultural and polymer degradation research are described. Specific examples are drawn from the various forms of headspace analysis with emphasis on the automated static equilibrium method.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 241-244 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Monosaccharides ; Polyols ; GC of TMS derivatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary This paper describes the gas chromatographic separation of the mixture of isopropylidene monosaccharides, and their trimethylsilyl derivatives. Based on the total analysis time and resolution the best stationary phase was SF-96 using Chromosorb G as the solid support and temperature programming.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 1612-1112
    Keywords: Phthalides ; Gas chromatography ; Chromosorb W ; Isomerization ; Ligustilide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary During GLC of naturally occurring mixtures of phthalides on packed columns an artefact was sometimes detected that originated from Z-ligustilide. Active sites of Chromosorb W were responsible for the formation of the artefact, that was assumed to be E-ligustilide as GC-MS revealed that its mass spectrum was identical with that of Z-ligustilide. No isomerization was observed when freshly coated Chromosorb W was used or the support was deactivated by benzoyl chloride or melamine. The identity of the artefact was confirmed by UV irradiation experiments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 704-706 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Isopropyliden-sorboses ; TMS-derivatives ; GC-MS combined technique ; Mass spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method has been developed using gas chromatography — electron impact mass spectrometry for the determination of the di-0-isopropylidene-sorbofuranose and mono-0-isopropylidene-sorbofuranose. The compounds are separated as their trimethylsilyl derivatives on a capillary column coated with the stationary phase SE-52. The mass spectra show that the silylation reaction is quantitiative and that the isopropylidene groups does not change.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 15 (1982), S. 183-185 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Analysis of ethylbenzene hydroperoxide ; Time normalization method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A gas chromatographic method, based on the time normalization technique, is described for the analysis of ethylbenzene hydroperoxide in mixtures containing ethylbenzene, acetophenone, 1-phenylethanol, benzaldehyde and phenol. Different liquid phases were tested and the best results were obtained with tricresyl phosphate and neopentyl glycol sebacate. The influence of the support, the liquid loading and the gas velocity are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 35-39 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Nitromethane ; Nitroalkanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Impurities in commercially available nitromethane have been determined by gas-liquid chromatography using six different column packings. Besides nitromethane, 1-nitropropane, 2-nitropropane, acetonitrile, methanol, small amounts of ethanol and acetaldehyde have been detected. The presence of formaldehyde, ethyl acetate and acetone is probable. Mixtures containing comparable amounts of the four nitroalkanes could be separated on all columns, but plots of logarithms of the retention times vs. carbon number or boiling points of the nitroalkanes or column temperatures were linear only in case of columns packed with Porapak R and Q.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Column characterization ; Oxidation ; Stationary phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The on-column oxidation of hydrocarbons commonly used as stationary phases in column characterization is investigated. In each case significant shifts of retention are observed, which may be negative or positive depending upon the polarity of the test solutes and the adsorptivity of the support material. In order to reduce the consequent uncertainties in the Rohrschneider [1] and McReynolds [2] polarity values, a new method of column characterization is proposed. The applicability of the new method is illustrated by a consideration of a range of silicone liquid phases.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 207-208 
    ISSN: 1612-1112
    Keywords: Trace determination ; Hydrogen chloride ; Ethylene oxide ; Gas chromatography ; Chlorinated solvents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A method is described for the determination of small quantities of hydrochloric acid in two chlorinated organic solvents (CHCl3 and CCl4). An excess of gaseous ethylene oxide is added to a liquid sample; the 2-chloroethanol formed is then analyzed by gas chromatography. The procedure is simpler and more sensitive in comparison with other conventional methods. It can be modified for other organic solvents.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 60-62 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Amines ; Derivatization ; Chloroformate esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The gas chromatographic analysis of amines after conversion to electron capture sensitive carbamates in two-phase systems has been studied. Hydrophilic compounds, for instance methylamine, are reacted with 2,2,2-trichloro-tert. butyl chloroformate. Quantitation below 10−7 M can be made by thermionic or electron capture detection. A hydrophobic amine, namely N,N-dimethyl-n-octylamine, was derivatized with 2,4,6-tribromophenyl chloroformate with addition of iodide ion to the aqueous phase. The favorable effect of iodide ion as well as the choice of pH and chloroformate ester is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 16 (1982), S. 107-111 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Thermionic ionization ; Catalytic flame ionization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A newly designed thermionic detector was operated in two modes of thermionic ionization detection (TID), and a third mode of catalytic flame ionization detection (CFID). Operating modes were varied by changing the composition of the electrically-heated thermionic/catalytic source, and the composition of gases supplied to the detector. A TID-2 source activated by a low concentration of Cs/ceramic was operated in a dilute H2/air environment and provided specific responses to nitrogen and phosphorus compounds. A TID-1 source activated by a high concentration of Cs/ceramic was operated in a N2 environment and provided very high specificities and picogram detectivities to compounds containing electronegative functional groups such as the NO2 group. A CFID source formed from Ni/ceramic was operated in a H2/air flame environment and provided universal responses to all organics with enhanced responses to some heteroatom compounds.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 269-284 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Liquid chromatography ; Phenols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Gas and high-performance liquid chromatographic methods in the analysis of phenols are reviewed. Among the great number of phenolic compounds analyzed, alkylphenols, chlorophenols, dihydroxy- and trihydroxybenzenes and biphenols are chiefly considered. The advantages and drawbacks of the methods are discussed, quoting the most important work. Relationships between the structural characteristics of phenols, the stationary phase structure, the mobile phase composition and the retention data are treated. Typical examples of the conditions for GC and HPLC analysis are summarized in tables. The literature comprises over 270 references, most of them recent.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 17 (1983), S. 421-425 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Purge and trap sampling ; Cryogenic focussing ; Water analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The most important operating parameters of a commercial purge and trap GC apparatus have been investigated. Band broadening problems arising from the slow desorption of compounds from the Tenax trap have been overcome by cryogenic focussing at the beginning of the column. Good results have been obtained with both packed and capillary columns. The sensitivity of the technique is sufficient to detect benzene in water at concentrations below 1μg kg−1 (1 ppb).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 18 (1984), S. 663-667 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Gas solubilities ; Enthalpies of solution ; Polar solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The gas-liquid chromatographic method has been used to determine the solubilities and partial molar enthalpies of solution of the gases H2S, CO2 and COS in four polar solvents. The results agree well with literature values obtained using conventional techniques, with the one exception of H2S in N-methyl-2-pyrrolidinone. In this case there is some evidence for the occurrence of adsorption at the gas-liquid interface.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Esterification in aqueous solution ; n-Butyl esters of aromatic polycarboxylic acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The direct esterification and gas chromatographic analysis of aromatic carboxylic acids as n-butyl esters is described. Derivatization is performed in aqueous solution with n-butanol in the presence of sulfuric acid. The butyl esters of benzoic, phthalic, hemimellitic, trimellitic, trimesic and pyromellitic acids permit their gas chromatographic separation from each other and from fatty acids and alipatic dicarboxylic acids. At mole ratios of [H2O]/ [n-BuOH]≤0.04 the water present does not interfere with the esterification reaction. At mole ratios above 0.04 anhydrous sodium sulfate is used for binding the water, at mole ratios of [Na2SO4 anh.]/[H2O]=0.25–0.75.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...