Determination of Methyl 2-Benzimidazolecarbamate in Soil by Competitive Inhibition Enzyme Immunoassay

Soil was analyzed for the fungicide or fungicide degradation product methyl 2-benzimidazolecarbamate (MBC) or carbendazim by employing commercially available polyclonal enzyme immunoassay (EIA) kits. MBC extraction from soil was done either by an overnight shaking with methanol-water (80:20) or by a 10-min 2 M ammonium chloride-ethanol shake followed by partitioning into methylene chloride. Intraassay and interassay percent coefficients of variation (% CVs) ranged from 2.2 to 13 for the standards and from 7 to 41 for the samples. A total of 101 soil samples obtained from Maine, Florida, and Switzerland were analyzed for MBC using EIA and liquid chromatography (LC). The correlation coefficients were 0.998 (tube EIA vs LC), 0.966 (plate EIA vs LC) and 0.946 (tube EIA vs plate EIA) when MBC concentrations were higher than 10 ppb. Detectable MBC concentrations ranged from 1 to 4778 ng/g. Detection limits were 2 ppb for the tube immunoassay, 1 ppb for the plate immunoassay, and 3 ppb for the HPLC. However, limit of quantitation was set at 10 ppb for all techniques