An enzyme immunoassay for the organochlorine insecticide hexachlorocyclohexane (HCH), through conversion to trichlorophenols

A method for immunoassay analysis of the organochlorine insecticide, hexach lorocyclohexane (HCH) has been developed, based upon alkaline conversion in standards and samples to trichlorobenzenes. The trichlorobenzenes were det ected through antisera developed to haptens containing either a trichlorobe nzene or trichlorpyridine moiety, developed using the herbicides, 2,4,5-tri chlorophenoxyacetic acid (2,4,5-T) and triclopyr, respectively. An enzyme c onjugate based on 2,4,5-trichlorophenol provided most sensitive and specifi c detection. Although the assays cross-reacted with the herbicides, they di d not suffer from the major disadvantage of extremely strong cross-reaction with cyclodiene organochlorines reported for a commercial HCH assay. The m ost sensitive assay had a lower detection limit of 20 mg l(-1) in drinking water and was applied to water and soil matrices.