DEVELOPMENT AND EVALUATION OF A DIPSTICK IMMUNOASSAY FORMAT FOR THE DETERMINATION OF ATRAZINE RESIDUES ON-SITE

On the basis of a semi-quantitative dipstick immunoassay (IA) for atra zine with visual detection (Giersch, T., J. Agric. Food Chem., 1993, 4 1, 1006), a quantitative format suitable as a field assay for the anal ysis of pesticide residues in water and liquid food samples on-site is described. For antibody immobilization, different membranes and immob ilization techniques were investigated. The measuring range for atrazi ne was 0.3-10 mu g l(-1) using reflectance detection. The total assay time was about 25 min with dipsticks previously coated with antibody. Atrazine-spiked water and liquid food samples were selected for assay evaluation. The samples could be measured directly without the need fo r any prior enrichment or clean-up steps. A satisfactory agreement was found between the results of the dipstick IA and HPLC or GC measureme nts of both the original and spiked samples.