Retention property of silica gel bonded with triacontyl groups as a packing material for GC

Abstract

Recently, octadecyl (C18), triacontyl (C30) and other chemically-bonded silica gels have been developed for HPLC. In this study, a C30 silica gel was selected and evaluated as a packing material for GC. Hexane, decane, tetradecane, ethyl acetate, 1-butanol, methyl isobutyl ketone and toluene were used as test samples. End-capped C30 silica was packed into a stainless-steel column (1/8 i.d., 150 mm long). All samples were detected using a flame ionization detector (FID). A relatively good linear relationship (r=0.992, n=8) existed between the logarithm of the retention factor (log k) and the boiling point of test samples using the C30 column at a column temperature of 150°C. Van’t Hoff plots of test samples were also linear (r≥0.989) over the range of column temperatures from 50°C to 200°C. It was inferred that the chemically-bonded C30 stationary phase behaved as a non-polar liquid phase and retained the sample by a gas-liquid partition chromatographic mode. The utility of a C30 silica gel as a GC chemically-bonded packing was favorable.