DETERMINATION OF ORGANOCHLORINE COMPOUNDS IN FATTY MATRICES - APPLICATION OF RAPID OFF-LINE NORMAL-PHASE LIQUID-CHROMATOGRAPHIC CLEANUP

A clean-up method for organochlorine compounds in fatty samples based on normal-phase liquid chromatography (NPLC) is described. To this end , an existing clean-up procedure which uses column switching for the s eparation of organochlorine pesticides (OCPs) and polychlorinated biph enyls (PCBs) from the fat matrix was simplified to a single silica LC column procedure. The use of an LC column packed with 3 mu m silica en ables complete fat/OCP separation in a total fraction volume of 12 ml, and results in a fully automated clean-up procedure that takes only 3 2 min per sample. The method showed average recoveries of 80-110% in t he concentration range of 1-510 mu g/kg, with relative standard deviat ions of less than 10%. Limits of determination were in the range of 0. 5-50 mu g/kg. The simplified approach has shown its potential for a va riety of samples, such as milk, pork fat, animal feed and cod liver oi l, showing its general applicability to fatty samples.