Prediction of Gas Chromatographic Retention Times of Fatty Acid Methyl Esters and n-Alkanes in Two Serially Connected Capillary Columns

Abstract

Equation (1) proposed by Krisnangkura et al. (J. Chromatogr. Sci. 1997, 35, 329-332) has been usedsuccessfully to predict gas chromatographic retention time of any solutes in a homologous series. It isextended, in this study, to estimate the mathematical hold up times of a two serially connected column. Theestimated hold up times are then used to predict the retention times of fatty acid methyl esters and n-alkanesat various iso-temperatures and carrier gas flow rates. The calculated retention times (tR(cal)) are in goodagreement with those of the experimental tR (tR(exp )) values. The greatest differences of tR for the fatty acidmethyl ester are 1.11% (at 225°C, 200kPa) and 1.22% (190°C, 200kPa) for the n-alkane. This studyconfirms the using of serially coupled capillary columns can be used without internal standards and anyother gas chromatographic modification.

Ink = a + bn + c/T + dn/T                 (1)

Keywords : Retention time / Hold up time / Fatty acid methyl ester / n-Alkanes / Gas chromatography/ Gas Chromatographic Identification / Two serially coupled capillary columns