Optimization of a technique of solid-phase micro-extraction and capillary gas chromatography with electron capture detection for the determination of nine organochlorine pesticides in drinking water

Nine organochlorine pesticides have been extracted from aqueous samples by SPME using a 7 mu m fibre of polydimethylsiloxane. The method was evaluated with respect to the time of fibre exposure, Limit of detection (LOD) and linearity and precision. The limits of detection depend on the compounds and vary between 0.04 and 0.22 mu g.L-1 for the concentration range studied between 0.05 and 1 mu g.L-1, with a coefficient of correlation usually > 0.97. For the organochlorine pesticides at a concentration of 0.3 mu g.L-1, the standard deviation varies from 4 to 23% depending on the compound. The recoveries obtained were 90-105%.