Development and Application of Laboratory and Field Immunoassays for Chlorpyrifos in Water and Soil Matrixes

Two sensitive tests were developed for monitoring the environmental dissipation of chlorpyrifos, using a high-affinity polyclonal antibody immobilized onto microwells and polystyrene tubes. The microwell assay, which required 90-120 min to perform, was designed for laboratory use and could detect 0.05-0.07 ppb of chlorpyrifos (85% B 0 ), with 50% inhibition of antibody binding (50% B 0 ) at 0.2-0.6 ppb of chlorpyrifos. The tube assay was designed for field use, required 15-20 minutes to perform, and had a lower limit of detection for chlorpyrifos of 0.15 ppb and 15-20 inhibition of antibody binding at 0.8-1.6 ppb