A study of the disappearance of pesticides during composting using a gas chromatography‐tandem mass spectrometry technique

Abstract

A simple method for multi-residue analysis of pesticides by low-pressure gas chromatography-tandem mass spectrometry (LP-GC-MS-MS) has been validated in compost samples. The pesticide residues were extracted from the lyophilised samples with organic solvent by stirring. No sample clean-up was required prior to the analysis. The method was applied to determine the fate of two organochlorine pesticides (lindane and endosulfan) and two organophosphates (malathion and chlorpyrifos-methyl) during the composting process in the reactor of a pilot plant. Malathion, chlorpyrifos-methyl and lindane residues almost fully disappeared after 8 days of maturation in the reactor, while endosulfan residues were only partially degraded. Alongside this, a study of natural disappearance of the pesticides was carried out in the laboratory and a characteristic time profile was traced for each pesticide class.