Isocratic reversed-phase high-performance liquid chromatographic separation of simple perhalogenated compounds

Abstract

An isocratic method for the separation of perhalogenated compounds using reversed-phase high-performance liquid chromatography is described. Nine perhalogenated compounds (CCl 4, CBrCl 3, CBrCl 2, CBr 4, C 2Cl 4, C 2Br 4, C 2Br 2Cl 4 and C 2Br 6) were divided into three groups as a function of carbon number and unsaturation and their separations were optimized. Methanol-water mobile phases in different proportions were used and the optimum conditions were determined for each of the groups and for a mixture of all nine compounds, based on resolution and separation factors. These conditions were then used to separate and identify perhalogenated compounds resulting from radiolysis, photolysis or thermolysis of different test solutions. Inversions of retention times were observed for some of the compounds as a function of the mobile phase polarity. This suggests that a gradient elution separation of these compounds would not result in a better separation.