Splitless large-volume GC-MS injection for the analysis of organophosphorus and organochlorine pesticides in vegetables using a miniaturised ethyl acetate extraction

A simple, rapid and sensitive multiresidue method has been developed for th e determination of ten organophosphorus and organochlorine pesticides, comm only used in crop protection. The analysis uses a miniaturised extraction w ith ethyl acetate followed by large volume injection (10 mu L) GC-EI-MS ana lysis in SIM (selective ion monitoring) mode. Sensitivity and selectivity o f the method were acceptable with limits of detection (LODs) lower than 0.0 1 mg kg(-1), except for endosulfan alpha and beta (0.05 mg kg(-1)). Average recoveries of between 63-99% were obtained and good linearity was observed in the range from 0.01 to 1.00 mg kg(-1). Repeatability and reproducibilit y studies yielded relative standard deviations lower than 20% in all the ca ses. The method was applied to the analysis of 110 tomato, pepper and cucum ber samples, as part of the monitoring programme of the Association of Prod ucers and Exporters of Fruits and Vegetables of Almeria.