Determination of trace atrazine levels in water by a sensitive magnetic particle-based enzyme immunoassay

Atrazine is a pre- and post-emergence selective herbicide specific for broad-leaved weeds and grasses. Although extensively applied in the United States, its use in Europe is limited and restricted. European drinking water regulations are strict: allowable atrazine contamination levels are 100 parts per trillion (ppt, ng/L). As a result of European regulations, increased method sensitivity is needed to detect atrazine-contaminated water supplies. A sensitive and rapid enzyme immunoassay using specific atrazine antiserum covalently coupled to a magnetic particle solid phase has been developed for the quantitation of atrazine in water at parts per trillion levels. The immunoassay provides accurate detection to as low as 15 ppt of atrazine directly from a 250 mu L water sample. Recovery from water samples without sample pretreatment averaged 100% and compared favorably to samples with GC/MS results (r = 0.993). The immunoassay represents a valuable method to detect trace amounts of atrazine in ground, surface, and drinking waters.