Antibody production and development of a polarization fluoroimmunoassay for the herbicide triclopyr

Abstract

This paper describes a homogeneous and competitive fluoroimmunoassay of polarization for the detection and quantification of the herbicide [(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid (triclopyr). Antibodies against triclopyr were produced by immunizing a rabbit with triclopyr–bovine serum albumin (BSA) conjugates. The fluoresceinamine labeled triclopyr were obtained, characterized and isolated. Two standard curves were obtained, one with a linear dynamic range (LDR) between 0.86 and 100 μg ml −1 of triclopyr and the other for lower concentrations (0.0007–100 μg ml −1). The minimum detectable concentration (MDC) was 0.7 ng ml −1 and the relative standard deviation (R.S.D.) was 1.96% (average value of three concentrations of the curve for n=8). The assay of specificity of the antiserum was developed using other molecules structurally very similar or usually found in formulations. The assay was very specific for triclopyr with respect to the other molecules tested. The technique provides good sensitivity, specificity, precision and MDC. This method was applied to triclopyr previously added to tap water and the recoveries obtained were between 97.9 and 130%.