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  • 1
    Electronic Resource
    Electronic Resource
    Reproducible glass capillary columns for analysis of nitrogen-containing organic bases (1977)
    Springer
    Russian chemical bulletin 26 (1977), S. 1502-1505 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. Using the high-pressure static method, highly efficient reproducible glass capillary columns, filled with the polar phase PEG-40M-KOH, were prepared for the analysis of aliphatic and heterocyclic nitrogen-containing organic bases. 2. It was shown that the retention index values of the amines remain constant when such columns are operated for 1.5 months.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00928540
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  • 2
    Electronic Resource
    Electronic Resource
    Thermodynamic evaluation of decrease in free energy of sorption of α-methyl-substituted organic nitrogen bases in analysis in glass capillary columns (1985)
    Springer
    Russian chemical bulletin 34 (1985), S. 469-475 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. A negative deviation from additivity has been detected, and evaluated, for the energy of van der Waals interaction in chromatography of methyl-substituted aliphatic, aromatic, and cyclic organic bases containing an Me group in the α position relative to the nitrogen atom. 2. The decrease in free energy of sorption is governed by the nature of the dispersion interaction, not by steric hindrance in the molecules of the α-methyl-substituted nitrogen compounds. 3. In the chromatography of α, α'-dimethyl derivatives or organic bases on a polar stationary phase, steric hindrance introduces an additional contribution to the decrease in the free energy of sorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00947702
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  • 3
    Electronic Resource
    Electronic Resource
    Predicting retention indices of methyl-substituted pyridines in gas capillary chromatography on the basis of the principle of the nonadditive change in the energy of sorption (1987)
    Springer
    Russian chemical bulletin 36 (1987), S. 2069-2074 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. Based on the experimental determination of the retention indices of the methylpyridines, the retention indices of six dimethyl and trimethyl pyridine derivatives have been determined with good accuracy by taking into account the nonadditive change of the energy of sorption of methylene groups. 2. The calculated values of the retention indices can be used for identifying methyl-substituted pyridines in complex mixtures for analyses performed on glass capillary columns with OV-101, OV-17, and PÉG-40M. 3. The deviations from additivity of the energy of sorption of methyl-substituted pyridines have been thermodynamically evaluated, and data on the dispersion nature of this phenomenon have been obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00961988
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  • 4
    Electronic Resource
    Electronic Resource
    Applicability of a universal equation in capillary gc for calculating the retention indexes and boiling points of members of O-, N-, and S-containing homologous series (1989)
    Springer
    Russian chemical bulletin 38 (1989), S. 254-259 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. The fundamental character of the universal equation proposed earlier for calculation of retention parameters of homologs in chromatography has been confirmed. It has been shown that the equation can be used with excellent results to calculate the boiling points of members of homologous series of organic compounds. 2. It has been demonstrated, using the example of 18 homologous series of organic compounds (alcohols, alkylamines, sulfides, mercaptans, nitroalkanes, isonitriles) that the equation can be correctly used to predict boiling points.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00953608
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  • 5
    Electronic Resource
    Electronic Resource
    Thermodynamic evaluation of character of interaction of aromatic hydrocarbons with polyethylene glycol in analysis in glass-capillary columns treated with KF or Na3PO4 (1983)
    Springer
    Russian chemical bulletin 32 (1983), S. 1801-1806 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. Glass-capillary columns with polyethylene glycol treated with KF or Na3PO4 are highly efficient and selective in the separation of benzene-series hydrocarbons. The presence of the salts does not influence the interaction of the hydrocarbons with the stationary phase. 2. A sharp increase has been found in the energy of dispersion interaction of aromatic hydrocarbon molecules with the stationary phase when the methyl substituents are in vicinal positions on the aromatic ring, and this increase has been estimated thermodynamically. An analysis of the literature data has made it possible to extend this conclusion to series of aliphatic and cyclic hydrocarbons with vicinal methyl groups. An increase of the contribution ofπ-complex formation to the energy of dissolution is manifested in the case of substituted benzenes containing more than three methyl groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00954649
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  • 6
    Electronic Resource
    Electronic Resource
    Prediction of the retention indices of methyl pyridines and pyrazines in capillary gas chromatography based on the non-linear additivity of the sorption energy (1988)
    Springer
    Chromatographia 25 (1988), S. 531-535 
    Details
    ISSN: 1612-1112
    Keywords: Gas liquid chromatography ; Fused-silica and glass capillary columns ; Separation of methyl pyridines and pyrazines ; Equations for the calculation of the retention indices
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Methylbenzenes, pyridines and pyrazines were investigated on fused-silica and glass capillary columns coated with SE-30 and PEG-40M/KF liquid phases, at two temperatures, 80° and 110°C. The contribution of the methylene groups to the partial molar free sorption energy was determined for methylpyridines and pyrazines. Equations are proposed for the calculation of the retention indices of methyl pyridines and pyrazines. These equations are based on the ortho- and α-effects of the methyl groups. The predicted indices have been experimentally tested for six dimethyl- and trimethylpyridines, and four methylpyrazines. Good accuracy of the calculation permits to use this method for the identification of methylpyridines and pyrazines in complex mixtures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02324828
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of KF and NA3PO4 on the change in differential molar free energy of sorption of polar substances during analysis in glass capillary columns with polyethylene glycol (1981)
    Springer
    Russian chemical bulletin 30 (1981), S. 1689-1694 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. The change in the energy contribution of the functional groups OH, NH2, NH, SH, Br, and C =O in a series of octane derivatives was studied by chromatography in glass capillary columns with polyethylene gly-col-40M after treatment with KF and Na3PO4. 2. The increase which we observed in the energy contributions of the functional groups which are hydrogen donors when analyzed on PEG in the presence of KF is attributed to their ability to form a hydrogen bond with the salt, the anion acting as a base. 3. We studied the effect of KF and Na3PO4 on the change in the energy contributions of the aromatic compounds toluene, nitrobenzene, and pyridine, compared to that of benzene. In the energy of sorption of pyridine, as well as a tertiary amine, it is probable that electrostatic interaction with the salts' metal ions makes a contribution. 4. In the analysis of n-alkanes on PEG, the differential molar free energy of solution due to the methylene group (ΔGCH 2) in unchanged in the presence of KF and Na3PO4.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00949474
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  • 8
    Electronic Resource
    Electronic Resource
    Inequality of temperature increments ofn-alkane homologs as one of the reasons for the nonlinear variation of sorption parameters of substances in temperature-programmed gas chromatography (1994)
    Springer
    Russian chemical bulletin 43 (1994), S. 591-594 
    Details
    ISSN: 1573-9171
    Keywords: temperature-programmed gas chromatography ; temperature increments forn-alkanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract GC behavior of C6-C17 n-alkanes has been investigated at different temperatures of isothermal analysis and under temperature programming conditions using two capillary columns coated with OV-101 and OV-351 stationary phases. Temperature increments have been calculated for the homologs and their inequality has been demonstrated for each member of then-alkane series. It was shown that the nonlinear individual temperature variation of the energy of dispersive interaction ofn-alkane homologs with the stationary phase, which was observed under isothermal conditions, may be one of the main reasons for the nonlinear change in sorption parameters ofn-alkanes in temperature-programmed gas chromatography.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00699830
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  • 9
    Electronic Resource
    Electronic Resource
    Analysis of polar compounds on PEG-40M/KF glass capillary columns (1979)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 2 (1979), S. 609-612 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography, cpillary, glass ; Stationary phase treatment by depositing differing salt traces into/onto layer ; Hexan plug mode for deposition of Na3PO4, K2CO3, KOH, KCl, KF ; KF (potassium fluoride) offers specific selectivity changes for primary/secondary aliphatic amine separation ; Donor-acceptor interaction discussed ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chromatographic properties of potassium fluoride as an additive to the polyethylene glycol stationary phase were investigated. This unique base in organic chemistry was shown to succeed in yielding good results for the analysis of polar compounds, including the primary amines. Glass capillary columns of high selectivity for primary and secondary aliphatic amines were obtained by the “hexane plug” procedure by which a thin layer of KF is deposited on the inner surface of glass capillary columns. Some possible types of donor-acceptor interactions occuring within the system PEG/KF/solute were considered.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240021005
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  • 10
    Electronic Resource
    Electronic Resource
    On-line hydrogenation of fatty acid methyl esters in capillary gas chromatography (1979)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 2 (1979), S. 43-44 
    Details
    ISSN: 0935-6304
    Keywords: Gas Chromatography ; Capillary, glass ; Fatty acid methyl esters structure analysis ; On-line hydrogenation, platinum catalyst precolumn ; 10-8ϕ in complicated natural mixtures ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An injection splitter in front of a glass capillary column was used for the hydrogenation of fatty acid methyl esters (FAME) mixtures. Hydrogenation followed by gas chromatographic analysis on capillary columns permitted detection and identification in complicated natural mixtures of branched fatty acids, showing minor structural differences, in quantities down to 10-8g.The technique described, apart from its suitability for FAME analysis, shows promise for structure determination studies of other classes of compounds.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240020113
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