Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Analyt Tech, Beijing 100039, Peoples R China
; Shenzhen Univ, Inst Nucl Technol, Shenzhen 518060, Peoples R China
Instrumental neutron activation analysis (INAA) has been used for the determination of extractable organohalogens (EOX) in milk. The detection limits are 50 ng, 8 ng and 3.5 ng for Cl, Br and I, respectively. The EOX concentrations in milk samples from various regions of China were determined. Meanwhile, organochlorine pesticides residues were detected by gas chromatography. The concentrations of the EOX in the milk samples are decreasing in the order of EOCl >> EOBr > EOI, and EOCl accounts for 95% of the total EOX. The average concentration of EOCl in milk is 4.44 mug/g expressed as fat weight basis, with the highest value of 17.6 mug/g from South China. The mean concentrations of total HCH and DDT are 0.038 mug/g and 0.046 mug/g, respectively. Organochlorine pesticides account only for 1.6% of the EOCl, indicating the very high proportion of the unknown EOCl in the milk sample.