Published:Journal of Chromatographic Science,
ISSN 0021-9665 Volume
45, Number 8, September 2007, pp. 492-506
Mathematical Models of Solute Retention in Gas
Chromatography as Sources of Thermodynamic Data. Part IV. Aliphatic
Alcohols as the Test Analytes
Katarzyna Ciazynska–Halarewicz, Monika
Helbin, Pawel Korzenecki, and Teresa Kowalska
Institute of Chemistry, Silesian University, 9 Szkolna Street,
40-006 Katowice, Poland
This study is the fourth consecutive part belonging
to the cycle devoted to an alternative approach to deriving certain
thermodynamic magnitudes. The previous three papers were dedicated,
respectively, to ketones, aldehydes, and alkylbenzenes. In our
present study (similar to the previous ones) the following working
procedure is adopted. With the aid of capillary gas chromatography,
the retention times are obtained for a wide variety of the aliphatic
alcohols. The analyses are carried out isothermally on stationary
phases of different polarity and at five different measuring
temperatures. These data constitute an experimental basis for
further processing with the aid of the specially devised mathematical
equations. The fitting parameters of these equations, due to
their physicochemical meaning, enable determination of certain
thermodynamic data. Nine equations used in this study are the
relationships coupling the selected retention data [relative
retention (r), non-reduced relative retention (rG), the retention
factor (k), or the Kováts retention index (I)] and a variety
of the physical magnitudes [the boiling point of the analyte
(TB), its molar volume (Vm), or its molar refraction (Rm)]. These
relationships are tested with respect to their performance to
predict the molar enthalpy of vaporization (DHvap) of the analytes
of interest (i.e., of aliphatic alcohols). Evaluation of the
equations’ performance is carried out through a comparison
of the numerical values generated from this approach with those
originating from the other methods, and a very good agreement
was found between these two series of the data. The best molar
enthalpy vaporization values (DHvap) are obtained from the retention
data originating from the most polar of the three investigated
stationary phases (i.e., DB-Wax). Models V and VIII proved the
best performing ones among the nine models tested in this study.
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