Analysis of Pesticide Residues in Olive Oil using Labelled Internal Standard

Dimethoate (O,O-dimethyl S-methylcarbamoylmethyl phosphorodithioate) is y a very toxic systemic insecticide which, as other organophosphates, kills insects by interfering with the action of important enzymes in the nervous system. The Food and Agriculture Organisation of the United Nations (Codex Alimentarius Commission, 1996), the World Health Organisation and the European Community (EC, 1976) have established the limits for dimethoate residue in olive and olive oil. A modern assay, based on the isotope dilution method, of this extremely dangerous pesticide in olives and olive oil extracts is presented. Selected Reaction Monitoring mass spectrometry/mass spectrometry (SRM-MS/MS) was used in connection with Gas-chromatography- chemical ionisation (GC-CI) and Ionspray (ISI) methods. OI sindona, giovanni/0000-0002-5623-5795; PERRI, ENZO/0000-0002-6314-7136; Tagarelli, Antonio/0000-0002-8811-1631