A. ARUL SELVI, M.A. SREENIVASA AND H.K. MANONMANI
Abstract
A simple competitive immunoassay was developed for the measurement of glyphosate in water samples. The assay employed the avian antibodies (IgY) that recognized glyphosate as a capture reagent and glyphosate alkaline phosphatase conjugate as an enzyme label. The assay depended on the competitive binding reaction between the antiglyphosate antibody and glyphosate derived from water samples for binding sites with immobilized glyphosate-OVA conjugate. The concentration of glyphosate in the water samples was quantified by the ability of the pesticide present in water samples to inhibit the binding of the enzyme conjugate to the antibody and subsequently the colour formation in the assay. The assay was specific to glyphosate with a limit of detection of 2 ng/mL. Mean analytical recovery of glyphosate in different water samples was 42.97 to 160.00%. The precision of the assay was satisfactory. Coefficients of variation were 0.002 to 1.24 and 0.055 to 1.41% for intra and inter assay precision respectively. The assay compared favourably with HPLC in its ability to accurately measure glyphosate in the water samples.