Science Inventory

Factors Affecting Atrazine Concentration and Quantitative Determination in Chlorinated Water

Citation:

WULFECK-KLEIER, K. A., M. D. YBARRA, T. F. SPETH, AND M. L. MAGNUSON. Factors Affecting Atrazine Concentration and Quantitative Determination in Chlorinated Water . JOURNAL OF CHROMATOGRAPHY A. Elsevier Science Ltd, New York, NY, 1217(5):676-682, (2010).

Impact/Purpose:

To inform public

Description:

Although the herbicide atrazine has been reported to not react measurably with free chlorine during drinking water treatment, this work demonstrates that at contact times consistent with drinking water distribution system residence times, a transformation of atrazine can be observed. Some transformation products observed through the use of high performance liquid chromatography-electrospray mass spectrometry are consistent with the formation of N-chloro atrazine. The amount of transformation is shown to be largely related to the amount of applied chlorine, pH, and reaction time. This paper further explores the implications of the transformation on the accurate determination of atrazine in drinking waters. The errors in the determination of atrazine are a function of the type of dechlorinating agent applied during sample preparation and the analytical instrumentation utilized. When a reductive dechlorinating agent, such as sodium sulfite or ascorbic acid is used, the quantification of the atrazine can be inaccurate by up to 3,000 percent. The results suggest HPLC/UV and ammonium chloride quenching may be best for accurate quantification. Hence, the results also appear to have implications for both compliance monitoring and health effects studies that utilize gas chromatography analysis with sodium sulfite or ascorbic acid as the quenching agent.