Pressurized liquid extraction of organochlorine pesticides from certified solid materials.

In order to propose a versatile method to use in laboratories devoted to environmental analysis, a scheme for the determination of organochlorine pesticides from different solid matrices is evaluated. Pressurized liquid extraction is chosen as the sample preparation technique, followed by the purification of the extract by means of solid-phase extraction with Envi-carb cartridge (100 m(2)/g). Finally, the extracts are analyzed by programmed temperature vaporization (PTV)-gas chromatography (GC)-electron-capture detection and PTV-GC-mass spectrometry. The suitability of the method for the analysis of different matrices is determined by the extraction and analysis of four certified reference materials of solid matrices: CRM 804-050 (soil), SRM 1941b (organics in marine sediment), SRM 1944 (New York/New Jersey waterway sediment) and SRM 1649a (Urban Dust). Good statistical concordance between the results obtained and the certified or reference concentration are observed for most of the analyzed pesticides.