LIQUID-CHROMATOGRAPHIC DETERMINATION OF PYRETHROIDS AS ACTIVE INGREDIENTS IN PESTICIDE FORMULATIONS

A normal-phase liquid chromatographic method for determining pyrethroi ds as active ingredients in pesticide formulations was developed. The method uses isooctane-ethyl acetate as mobile phase and UV detection a t 275 nm. The method was evaluated for the following 7 pyrethroid acti ve ingredients: alpha-cypermethrin, cypermethrin, deltamethrin, esfenv alerate, fenvalerate, fenpropathrin, and permethrin. Evaluation covere d 3 formulation types (emulsifiable concentrate, suspension concentrat e, and water-dispersible granule) containing a single pyrethroid activ e ingredient. The method separates diastereomers of cypermethrin, fenv alerate, and permethrin and can be used to determine total content as well as relative distribution of diastereomers.