PERFORMANCE OF 2 IMMUNOASSAYS FOR THE DETERMINATION OF ATRAZINE IN SEA-WATER SAMPLES AS COMPARED WITH ONLINE SOLID-PHASE EXTRACTION LIQUID-CHROMATOGRAPHY DIODE-ARRAY DETECTION

Two immunoassay formats, magnetic particles-based assay (Atrazine RaPI D assay and Atrazine High-Sensitivity RaPID assay) and microtiter plat e based assay (Department of Entomology and Environmental Toxicology, University of California in Davis) were evaluated for the determinatio n of atrazine in sea water samples. The results obtained were compared and validated with those obtained by using on-line solid phase extrac tion followed by liquid chromatography-diode array detection (on-line SPE-LC-DAD). The correlation between both techniques was good when ana lyzing levels of atrazine ranging from 0.01 to 5 mu g/l in samples sho wing salt concentration values varying from 0 to 35 g/l and pH values from 2 to 10. One of these immunoassays (Atrazine High-Sensitivity RaP ID assay) was employed to directly analyze atrazine in real estuarine and coastal water samples. The same samples were analyzed after filtra tion and C-18 Empore disks extraction.