Quantification of 2,4,5-trichlorophenoxyacetic acid by fluorescence enzyme-linked immunosorbent assay with secondary antibody Original Research Article

This paper describes a fluorescence enzyme-linked immunosorbent assay (ELISA) for the quantification of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) with an anti-rabbit secondary antibody conjugated to peroxidase (goat anti-rabbit IgG-HRP) for sandwich antibody assay. Human gamma globulin (HGG) conjugated to 2,4,5-T was readily coated on a polystyrene microplate. Data acquisition on microtiter wells is performed by a spectrofluorimeter through a fibre optic. The standard curve was produced for 0.01–5000 ng ml−1 2,4,5-T. The minimum detectable concentration was 0.023 ng ml−1 and the relative standard deviation was 6.9% for a 5 ng ml−1 sample (n=10). The ELISA procedure was selective with respect to structurally similar compounds usually found in pesticide formulations. This method was applied to 2,4,5-T previously added to apple juice.