Determination of organochlorine pesticides in cheese

A multiresidue technique was developed for the analysis of 17 organochlorine compounds in cheese: alpha-hexachlorocyclohexane (alpha-HCH), beta-HCH, gamma-HCH, delta-HCH, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, chlordane, o,p'- ... (o,p'-DDT), p,p'-DDT, o,p'- ... (o,p'-DDD), p,p'-DDD, o,p'- ... (o,p'-DDE), p,p'-DDE, and the fungicide hexachlorobenzene. In this technique, the fat, previously extracted from the cheeses, was subjected to 2 cleanup and extraction methods: with H2SO4, for acid-resistant organochlorine pesticides, and with KOH-ethanol. The behavior of the compounds in both treatments enabled us to identify the organochlorine pesticides in cheese. The precision (repeatability and reproducibility) and accuracy of the technique were validated.