SUPERCRITICAL FLUID-BASED CLEANUP TECHNIQUE FOR THE SEPARATION OF ORGANOCHLORINE PESTICIDES FROM FATS

A supercritical fluid cleanup technique for the separation of organochlorine pesticides from fats has been developed. The technique uses either an alumina column or a silica column with a supercritical mobile phase of carbon dioxide or methanol/carbon dioxide (2 mol % methanol), respectively. The lipid matrices were chicken fat with incurred residues of heptachlor epoxide, dieldrin, and endrin at low parts per million levels and lard spiked with lindane, heptachlor, hetachlor epoxide, dieldrin, endrin, and o,p'-DDT at low parts per million levels. Recoveries (93-111 %) and precision (% RSD less-than-or-equal-to 8.5) obtained with the supercritical fluid technique compare favorably with those obtained by conventional column cleanup methodology.