Ts. Lawruk et al., DETERMINATION OF METOLACHLOR IN WATER AND SOIL BY A RAPID MAGNETIC PARTICLE-BASED ELISA, Journal of agricultural and food chemistry, 41(9), 1993, pp. 1426-1431
A competitive enzyme-linked immunosorbent assay (ELISA) for the quanti
tation of metolachlor in water and soil was developed using a magnetic
particle-based solid phase. Metolachlor was covalently attached to bo
vine serum albumin carrier through the chloroacetamide moiety and the
resulting herbicide-protein immunogen used in rabbits to produce polyc
lonal antibodies specific for metolachlor. The polyclonal antibodies a
re covalently attached to amine-terminated superparamagnetic particles
and used as the solid phase in a rapid and sensitive immunoassay. Thi
s ELISA has a limit of detection of 0.05 ppb (parts per billion, nanog
rams per milliliter) in water and 3.0 ppb in soil. The ELISA compares
favorably with GC measurements when water samples are analyzed (r=0.97
6). Recoveries from fortified soils averaged 83% and 90% using 30-min
and 24-h extractions with methanol/water (75:25 v/v), respectively.