title: Indirect determination of the pesticide dimethoxydithiophosphate in an FIA-AAS system with liquid-liquid back-extraction.
abstract: A method has been developed for the determination of dimethoxydithiophosphate (DDTP) by liquid-liquid extraction in a flow-injection analysis (FIA) system with detection by atomic-absorption spectrometry (AAS). It is based on the formation of the Cu(DDTP)(2) complex and its extraction into chloroform, and back-extraction of the copper with an ammonia buffer (pH 10). The method uses small amounts of samples, avoids handling errors and is fast and highly reproducible. It features a detection limit of 0.39 ppm DDTP (2.45 x 10(-6)M in the organic phase) and a relative standard deviation of 1.6%. The method has been applied to the determination of the organophosphorus pesticide malathion in an agricultural formulation.
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Science, University of Salamanca, 37008 Salamanca, Spain.
authors.forename: O J
authors.initials: OJ
authors.lastname: de Blas
authors.forename: J L
authors.initials: JL
authors.lastname: de Paz
authors.forename: J H
authors.initials: JH
authors.lastname: Mendez