High-performance liquid chromatography with diode-array detection for the determination of pesticides in water using automated solid-phase extraction

Abstract

An accurate, economical and sensitive method was developed for the simultaneous determination of phenylureas, phenoxy acids, some nitriles and nitrophenols in aqueous samples. The method is based on automated solid-phase extraction and high-performance liquid chromatography with diode-array detection. The analytes were separated on a 25 cm C₁₈ analytical column and determined at three wavelengths simultaneously, 220, 240 and 270 nm. The solid-phase extraction time was less than 1 h for six water samples and the lowest detectable concentrations were in the range 25–100 ng l^–1 The recoveries of the pesticides ranged from 85 to 99% and the relative standard deviations were in the range 1–10% at 200 ng l^–1(n= 6).