Recent advances in cleanup of fats by sweep co-distillation. Part 1: Organochlorine residues.

A redesigned fractionation tube has resulted in development of a new, commercial sweep co-distillation unit. It is compact, reliable, cost-efficient, and permits cleanup of pesticides in up to 10 fat samples simultaneously. Recovery of several organochlorine residues (HCB, alpha-BHC, lindane, heptachlor epoxide, dieldrin, p,p'-DDE, p,p'-DDD, p,p'-DDT) at ppm and ppb levels in meat (beef) fat are 83-105%, with coefficients of variation between 4 and 6%. Cleaned up extracts are quantitated by gas chromatography using an electron capture detector with a vitreous silica capillary column containing a medium polarity bonded phase.