Evaluation of commercial immunoassays for the detection of alachlor in milk, eggs and liver.

For regulatory purposes, there is a need for rapid, uncomplicated, and inexpensive methods to monitor pesticide residues in food. Commercial immunoassay kits from 3 manufacturers were evaluated for the detection of alachlor in cow milk and urine, and one kit was chosen for assay of chicken eggs and livers. Milk and urine were analyzed after a 1:2 dilution in water, and a rapid extraction procedure was developed for eggs and liver samples. Assays of incurred samples were performed after dosing a cow and several chickens with alachlor. Alachlor was detected in milk and eggs, but not in livers from hens dosed up to 12 mg/kg body weight. The ELISA detection limits were 0.3 ng/mL in milk, 2 ng/g in eggs, and 3 ng/g in liver. The major drawback with the kits was the low cross-reactivity of the antibodies for some of the alachlor metabolites.