Determination of Aldicarb, Aldicarb Sulfoxide, and Aldicarb Sulfone in Oranges by Simple Gas–Liquid Chromatography with Nitrogen–Phosphorus Detection

Abstract

Abstract A reversed-phase liquid chromatographic method, using an acetonitrile–water gradient mobile phase, and a gas-liquid chromatographic method with nitrogen–phosphorus and flame photometric detection were compared for simultaneous and separate determinations of trace quantities of aldicarb and its metabolites aldicarb sulfone and aldicarb sulfoxide. One hundred gram samples of fortified oranges were extracted with water–acetone, water-acetonitrile, or water–methanol, and the extracts were partitioned with methylene chloride. Partitioning with other organic solvents such as chloroform, ethyl acetate, or methyl isobutyl ketone was also investigated. When performed under optimal conditions, the procedure has detection limits of 0.4, 0.8, and 0.4 ppb for aldicarb, aldicarb sulfoxide, and aldicarb sulfone, respectively. Recoveries at fortification levels of 4,20, and 80 ppb ranged from 75 to 90%. Coefficients of variation ranged from 8 to 10%.