QUANTIFICATION OF CYANAZINE IN WATER AND SOIL BY A MAGNETIC PARTICLE-BASED ELISA

A competitive enzyme-linked immunosorbent assay (ELISA) for the quanti tation of cyanazine in water and soil was developed using a novel magn etic particle solid phase. Cyanazine was covalently attached to a bovi ne serum albumin carrier, and the resulting herbicide-protein conjugat e was used in rabbits to produce polyclonal antibodies specific for cy anazine. Specificity studies indicate that the antibody can distinguis h cyanazine from other structurally similar triazine herbicides, inclu ding atrazine. This ELISA has a limit of detection of 0.035 parts per billion (ppb, ng/mL) in water and 3.5 ppb in soil. The standard curve allows quantitation up to 3.0 ppb in water and 300 ppb in soil. The EL ISA compares favorably with GC measurements in the analysis of water s amples (r = 0.964). Recoveries from fortified soils averaged 86% using a 24-h extraction with methanol/water (75:25 v/v).