Separation of Pesticides and Impurities by Countercurrent Chromatography

Abstract

Countercurrent chromatography (CCC) was chosen for study as an isolation technique for pesticides and the impurities found with them, because its high capacity makes possible comparatively large batches of purified materials and because its mild operating conditions minimize the danger of degradation during the separation. Technical grade fenthion, an organophosphorus insecticide, showed traces of six impurities. The principal one found in an analytical standard fenthion was identified as 3-methyl-4-(methylthio)anisole, well separated from the fenthion. The n-octyl ester of the herbicide 2,4,5-T was easily separated from the methyl ester impurity.