Determination of Selected Organochlorine Pesticides and Polychlorinated Biphenyls in Human Serum*

Abstract

A method is presented that can be used to determine the residue level of certain chlorinated pesticides and polychlorinated biphenyls (as Aroclor 1260) in serum. The method involves the following: (1) extraction of denatured serum with organic solvents; (2) elution of the organic extract through micro-Florisil^®† columns to obtain two fractions; (3) acid treatment of the less polar Florisil fraction and its subsequent elution through deactivated silica gel to obtain two fractions; and (4) analysis of all three fractions using gas-liquid chromatography with electron capture detection. The method produced in vitro recoveries for 10 pesticides spiked in the range of 1–10.7 ppb of 50.4% to 121.6%, and in the range of 4.98–21 ppb, recoveries ranged from 47.7 to 112.6. In vivo “recoveries” of Aroclor 1260 averaged 104.8% and 92.3% for concentration levels of ∼ 10 and ∼ 30 ppb, respectively. The method could not be compared with the more commonly used hexane extraction technique because of the deleterious effect these extracts had on the gas chromatographic system.