Peculiarities of aromatic hydrocarbon retention in normal-phase high-performance liquid chromatography with eluents containing halide derivatives.

The possibility of regulating the retention and selectivity of monoalkyl- and polymethyl-substituted aromatic hydrocarbons in normal-phase high-performance liquid chromatography was investigated by modifying the non-polar (hexane) mobile phase with halide derivatives of hydrocarbons. Dichloromethane, chloroform, carbon tetrachloride and ethyl bromide were employed as modifiers. The decrease in relative retention for small mole fractions of modifier in the eluent increased with decrease in the polarity. The retention mechanism of the aromatic hydrocarbons is discussed. Chromatograms for the group separation of diesel fuel aromatic hydrocarbons are presented.