An Enzyme Immunoassay for the Organochlorine Insecticide Hexachlorocyclohexane (HCH), Through Conversion to Trichlorophenols

A method for immunoassay analysis of the organochlorine insecticide, hexachlorocyclohexane
(HCH) has been developed, based upon alkaline conversion in standards and samples to
trichlorobenzenes. The trichlorobenzenes were detected through antisera developed to
haptens containing either a trichlorobenzene or trichlorpyridine moiety, developed using the
herbicides, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and triclopyr, respectively. An enzyme
conjugate based on 2,4,5-trichlorophenol provided most sensitive and specific detection.
Although the assays cross-reacted with the herbicides, they did not suffer from the major
disadvantage of extremely strong cross-reaction with cyclodiene organochlorines reported
for a commercial HCH assay. The most sensitive assay had a lower detection limit of 20 mg
l–1 in drinking water and was applied to water and soil matrices.