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  • 1
    Electronic Resource
    Electronic Resource
    Empirical correlations between gas-chromatographic retention data and physical or topological properties of solute molecules
    Amsterdam : Elsevier
    Analytica Chimica Acta 223 (1989), S. 161-174 
    Details
    ISSN: 0003-2670
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0003-2670(00)84081-7
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  • 2
    Electronic Resource
    Electronic Resource
    Thermodynamic properties of alkylbenzenes from retention-boiling point correlations in gas chromatography (1997)
    Springer
    Chromatographia 44 (1997), S. 179-186 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Retention-boiling point correlation ; Trouton's rule ; Alkylbenzenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A thermodynamic interpretation of the empirical correlation between retention and boiling point for alkylbenzenes in stationary phases of low and medium polarity has been found. The transfer of molecules between the liquid and mobile phases was assumed to be similar to, although not identical with, vaporization of any given pure liquid and characterized using the Trouton's rule. The two equations developed relate relative retentions to solute boiling point and two systems constants under a given set of conditions. The first equation was found to give a better description since it involves fewer assumptions and approximations. Validity of the model was confirmed by agreement between theoretical and experimental values for equation constants although the agreement becomes poorer as the stationary phase polarity increases. The relationships discussed are applicable to all congeneric solutes of low polarity in stationary phases of medium polarity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02466453
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  • 3
    Electronic Resource
    Electronic Resource
    Limitations of evaluation methods for inhibited oxidation of hydrocarbons in the liquid phase. Expressions based on oxygen consumption (1989)
    Springer
    Reaction kinetics and catalysis letters 39 (1989), S. 115-122 
    Details
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Рассмотрены три уравнения, основанные на данных расхода кислорода и позволяющие определить константы скорости взаимодейс твия пероксидных радикалов с молекулами ингибитора. Найдено, что эти уравнения не дают удовлетворительных результатов и для определения констант скоростей необходимыми являются полные кривые расхода кислорода во времени.
    Notes: Abstract Three equations based on oxygen consumption data by which the rate coefficient of the reaction between peroxy radicals and inhibitor molecules can be calculated has been investigated. It was found that these equations do not give acceptable results and that the entire oxygen uptake vs. time curve is necessary for the determination of this rate coefficient.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02061864
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  • 4
    Electronic Resource
    Electronic Resource
    Limitations of evaluation methods for inhibited oxidation based on chemiluminescence (1989)
    Springer
    Reaction kinetics and catalysis letters 38 (1989), S. 51-56 
    Details
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Применяли различные уравнения, основанные на данных хемолюминесценции, для определения констант скоростей реакций перокси-радикалов с молекулами ингибитора.
    Notes: Abstract The applicability of different equations based on chemiluminescence data by which the rate coefficient of the reaction between peroxy radicals and inhibitor molecules can be calculated has been investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02126252
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  • 5
    Electronic Resource
    Electronic Resource
    Determination of heats of vaporization and gibbs free energies of alkylbenzenes on GC stationary phases of different polarity (1998)
    Springer
    Chromatographia 48 (1998), S. 89-94 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Heats of vaporization ; Gibbs free energies ; Kováts retention indices ; Alkylbenzenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In our paper we propose a new method for the determination of heats of vaporization (ΔH vap(i)) and the Gibbs free energies of vaporization (Δμp(i)) for individually selected alkylbenzenes, chromatographed on stationary phases of low and medium polarity. The method is based on a new thermodynamic description of the Kováts retention index (I (i)) making use of Trouton's rule. In fact, we attribute physical significance to two empirical relationships, well known from the literature. We can describe thermodynamically the magnitude ofI (i) using two relations, each of them potentially useful for further determination of δH vap(i) and Δμp(i). A comparison was made of the results obtained with the use of our new approach and of those already existing in the literature attained in a completely different way. The comparison suggests that the calculated δH vap(i) and Δμp(i) values are thermodynamically acceptable and hence correct, and the data suit into the series of similar values determined on stationary phases of different polarity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467523
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  • 6
    Electronic Resource
    Electronic Resource
    Quantitative Analysis of aliphatic aldehydes by headspace SPME sampling and ion-trap GC-MS (1998)
    Springer
    Chromatographia 48 (1998), S. 127-132 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography-mass spectrometry ; Solid-phase microextraction ; Headspace analysis ; Unsaturated aldehydes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A fast and simple headspace SPME sampling method has been developed for quantification of volatile aliphatic aldehydes in sunflower oil. Analysis has been performed by gas chromatography, on a 30m×0.25 mm i.d. ×0.25 μm CP-Wax 52CB column, with mass spectrometric detection. Carryover from the SPME fiber could be eliminated by heating the fiber in the injection port between runs. Response factors of all the compounds were linear for concentrations up to 100 ng μL−1. The slopes of the calibration curves decrease with the amount of saturation of the aldehydes. The average responses for unsaturated aldehydes were twice as high as those for the saturated variety. Responses for dienes were approximately one order of magnitude higher than for saturated aldehydes. Depletion of the analyte was examined by repeated extraction from the same vial. SPME was optimized—after 30 min extraction most components were found to have reached equilibration. The detection limit for the compounds studied varied between 0.1 and 1 ng μL−1. Distribution constants were determined for ten different aldehydes and Henry's constants were calculated for unsaturated aldehydes. There was a definite relationship between the response factors and the amount of saturation of the aldehydes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02467528
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  • 7
    Electronic Resource
    Electronic Resource
    Empirical correlation equations describing retention data of hydrocarbons on dinonylphatalate and polyethyleneglycol 4000 (1988)
    Springer
    Chromatographia 25 (1988), S. 725-730 
    Details
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Structure-retention correlation ; Kováts retention index ; Alkylaromatics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Relative retention data and Kováts retention indices were measured for several hydrocarbons (mainly for alkylbenzenes) on dinonylphtalate and polyethylenelycol 4000 stationary phase. Correlations were searched between these retention data and the following physical (boiling point, molrefraction, molvolume) and topological (connectiviity index and general index of molecular complexity) properties of solutes. The best fitting equations was choosen among more than 150 equations involving linear, quadratic, exponential, two variables linear and quadratic dependence of retention data and the properties mentioned as well as their inverses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02290480
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  • 8
    Electronic Resource
    Electronic Resource
    Discrimination between linear and non-linear models describing retention data of alkylbenzenes in gas-chromatography (1990)
    Springer
    Chromatographia 29 (1990), S. 375-384 
    Details
    ISSN: 1612-1112
    Keywords: Gas-chromatography ; Quantitative structure-retention relationships ; Kováts retention index ; Alkylaromatics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Detailed statistical analysis is presented to describe the retention indices of alkylbenzenes as a function of their physical (boiling point, modrefraction) and topological (connectivity and complexity indices) properties. With the help of several statistical characteristics (examination of residuals, F test, partial F test, termination criteria, correlation indices) a discrimination is made among different models. A nonlinear equation was chosen which describes the retention data on slightly polar phases with the practically attainable precision. A comparison with literature sources shows that this equation provides the smallest residual error and, hence, it can be applied for prediction purposes. A correlation was found between the preexponential factor in the simple exponential model and the polarity of stationary phases on the Tarján scale.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02261306
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  • 9
    Electronic Resource
    Electronic Resource
    Rate constants for the addition of the 2-hydroxy-2-propyl radical to alkenes in solution (1993)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 25 (1993), S. 913-920 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute rate constants for the addition of the 2-hydroxy-2-propyl radical to 18 substituted alkenes (CH2 = CXY) were determined at (296 ± 1) K in 2-propanol by time-resolved electronspin-resonance spectroscopy. With alkene substitution the rate constants vary by more than 6 orders of magnitude. For 3,3-dimethyl-but-1-ene the temperature dependence is given by log k/M-1 · s-1 = 6.4 minus;; 19.1/Θ where Θ = 2.303 RT in kJ/mol-1. As shown by a good correlation with the alkene electron affinities, log k296/M-1 · s-1 = 6.46 + 1.71 · EA/eV (r = 0.930), 2-hydroxy-2-propyl is a very nucleophilic radical, and its addition rates are highly governed by polar effects. © 1993 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550251105
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  • 10
    Electronic Resource
    Electronic Resource
    Rate constants for the addition of the 2-cyano-2-propyl radical to alkenes in solution (1993)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 25 (1993), S. 249-263 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute rate constants for the addition of the 2-cyano-2-propyl radical to 26 alkenes CH2=CXY at 315 K were determined in solution by time-resolved electron-spin-resonance spectroscopy. They vary with the alkene substituents from 30 M-1 s-1 to 7′010 M-1 s-1. For styrene the temperature dependence is given by log k/M-1 s-1 = 7.7 - 26.1/Θ where Θ = 2.303 RT in kJ/mol. An analysis of the substituent effects in terms of polar and enthalpic factors reveals a dominant influence of the overall reaction enthalpy. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550250405
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