ENZYME-IMMUNOASSAY TECHNIQUES FOR THE DETECTION OF ATRAZINE IN WATER SAMPLES - EVALUATION OF A COMMERCIAL TUBE BASED ASSAY

Environmental immunoassays can help lower the operating costs and impr ove the effectiveness of residue laboratories. The present study asses ses the ability of a commercially available enzyme immunoassay (EIA) t o detect triazine herbicides in water. The tube based EIA could detect atrazine in lake and river water with detection limits of 62 pg/mL an d 180 pg/mL respectively. The assay's ability to quantify atrazine in a set of 124 water samples taken from many parts of Canada was compare d with a reference method that used gas chromatographic separation com bined with a nitrogen phosphorous detector (GC-NPD) (R-0.919). A 71 % reduction in analytical load was achieved at a threshold concentration of 1 ng/mL. There were 2.4 % false negative and 0.8 % false positive results associated with that load reduction. The variability of the as say control parameters was generally within two standard deviations of the mean response for 65 assays. The EIA for atrazine is recommended for use as a screening technique and as an inexpensive way to monitor triazine levels in waters that are known to be contaminated with those herbicides.