DETERMINATION OF BENOMYL (AS CARBENDAZIM) AND CARBENDAZIM IN WATER, SOIL, AND FRUIT JUICE BY A MAGNETIC PARTICLE-BASED IMMUNOASSAY

A competitive enzyme-linked immunosorbent assay (ELISA) for the quantiation of benomyl (as carbendazim) and carbendazim in water was developed. This assay utilizes magnetic particles as the solid phase to attach polyclonal rabbit anti-carbendazim antibodies. The ELISA has an estimated detection limit of 0.1 part per billion [ppb (nanograms per milliliter)] of carbendazim in water. It compares favorably with HPLC measurements in the analysis of water samples (r = 0.920). Studies indicate that this immunoassay can also be used for the determination of carbendazim in fruit juice and soil. Fortified juice samples, diluted 1:300 for the ELISA, averaged 103% recovery with a detection limit of 300 ppb. A fortified soil sample recovered greater than 85% in the immunoassay with an estimated detection limit of 37.5 ppb of carbendazim using a 0.5-3-h extraction with methanol/0.5 N sodium hydroxide (3:1 v/v).