GAS-CHROMATOGRAPHIC DETERMINATION OF ACEPHATE IN TECHNICAL MATERIAL AND SOLUBLE POWDER FORMULATIONS - COLLABORATIVE STUDY

A gas chromatographic (GC) method was developed for quantitation of ac ephate (Orthene) in technical material and soluble powder formulations . Acephate is an organophosphate with broad spectrum contact and syste mic insecticidal properties. Fourteen collaborators from 8 countries p articipated in a collaborative study of the method. Collaborators were provided with the method; samples of technical acephate and formulate d soluble powder containing 95-99% and 71-75% acephate, respectively; an acephate reference standard; and internal standard. Samples were we ighed, diluted to volume with internal standard, and quantitated by us ing GC peak area ratios. Relative standard deviation values for reprod ucibility (RSDR) were 1.03-2.55 for 95-99% technical acephate and 1.36 -2.73 for formulated soluble powder containing 71-75% acephate. The GC method for determination of acephate in technical material and solubl e powder formulations has been adopted by AOAC INTERNATIONAL.