Dual column and derivative techniques for improved specificity of gas-liquid chromatographic identification of organochlorine insecticide residues in soils

Abstract

Derivatives of organochlorine insecticides exhibiting R_t values substantially different from those of the parent insecticides were obtained for pp′-TDE, pp′-methoxychlor, op′-DDT and pp′-DDT on treatment with 2 per cent. ethanolic potassium hydroxide, and for endrin and dieldrin with ethanolic concentrated hydrochloric acid; partial clean-up of soil extracts was achieved by the alkali treatment. The use of dual columns, namely, DC-200 and diethylene glycol succinate, in conjunction with derivative formation, provided R_t values sufficiently different for improved organochlorine insecticide identification with minimal additional effort.