AWWA JAW60866

Atrazine is one of the most commonly used herbicides in the United States, therefore it is a regulatory concern and is extensively monitored in the environment, especially in drinking water. Because of the higher costs of gas chromatography (GC) methods, utility managers and regulators are considering the increased use of enzyme-linked immunosorbent assay (ELISA) methods for monitoring atrazine. An ELISA test kit was recently approved by the US Environmental Protection Agency. The research in this article points out potential biases and inaccuracies that may occur with such test kits. ELISA test kits for atrazine are typically precise (repeatable) but often have a tendency for a positive bias from unknown interferences. Negative biases are also observed in some cases, which suggest a lower atrazine concentration than is actually present. The results of this research can help utilities and regulators to better determine the best use of ELISA versus GC methods for analyzing atrazine with respect to monitoring and/or process control. Includes 36 references, tables, figures.