Determination of chlordane in human blood by gas chromatography
A clean-up method for the removal of organochlorine interference prior to the determination of chlordane by gas chromatography was studied. Chlordane, polychlorinated biphenyls and organochlorine pesticides were treated with a cold mixture (5 ml) of concentrated sulphuric acid and fuming nitric acid (1 + 1 V/V) at 0 °C for 15 min. The product was mixed with cold water (100 ml) and submitted to continuous distillation (cyclic steam extraction) for 90 min to extract chlordane into 3 ml of heptane. The extract was cleaned up by reduction with iron in acetic acid and the chlordane was determined by gas chromatography with electron capture detection. The acid treatment removed polychlorinated biphenyls and organochlorine pesticides, which gave peaks overlapping those of chlordane. The method was applied to the determination of chlordane in human blood. The blood sample was haemolysed with water and extracted with acetone-hexane (1 + 9 V/V), and the extract was treated by the above method. The recovery of chlordane added to human blood was above 88%.