Simultaneous Determination of Azadirachtin and Avermectin B1a by Reverse Phase HPLC

A reverse phase high performance liquid chromatographic method for the simultaneous determination of azadirachtin and avermectin B1a in mixed emulsifiable concentrate (EC) was developed. The procedure adopted a C18 column(Hypersil ODS 250 mm×4 mm) with UV detection at λ 215 nm(azadirachtin) and λ 240 nm(avermectin B1a). The recoveries of azadirachtin ranged from 97.5% to 105.0%, and avermectin B1a, from 98.0% to 107.5%. The relative standard deviation of azadirachtin and avermectin B1a were 1.70% and 1.60% respectively. The proposed method achieved the goal of simplicity, rapidity and accuracy.