Rapid determination of abamectin in lettuce and cucumber by high-performance liquid chromatography

Abstract

A rapid, sensitive and reliable method is presented for the determination of trace amounts of abamectin in lettuce and cucumber. Abamectin consists of ⩾80% avermectin B1a and ⩽20% avermectin B1b. Vegetables were extracted with ethyl acetate and the extract was purified by solid-phase extraction using Sep-Pak silica cartridges. The purified extracts were analysed by high-performance liquid chromatography with a 5-μm Zorbax ODS column and UV detection under isocratic conditions. The method yields recoveries for avermectin B1a and B1b of 76—109% in the 0.054—0.54 mg/kg range. The limit of detection of the method is 40 μ/kg each of avermectin B1a and B1b in vegetables.