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METHOD 535: MEASUREMENT OF CHLOROACETANILIDE AND CHLOROACETAMIDE HERBICIDE DEGRADATES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)
Citation:
Shoemaker, J A. AND M Bassett. METHOD 535: MEASUREMENT OF CHLOROACETANILIDE AND CHLOROACETAMIDE HERBICIDE DEGRADATES IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS). U.S. Environmental Protection Agency, Washington, DC, 2005.
Impact/Purpose:
Develop an analytical method for the analysis of alachlor ESA and other acetanilide pesticide degradation products. The draft method, suitable for use in assessing occurrence of the pesticide degradation products as part of the Unregulated Contaminant Monitoring Rule (UCMR), will be delivered to OGWDW by February 2004. The final peer-reviewed method was delivered in September 2004.
Description:
Over the past several years, ethanesulfonic acid (ESA) and oxanilic acid (OA) degradation products of acetanilide/acetamide herbicides have been found in U.S. ground waters and surface waters. The substitution of the sulfonic acid or the carbonic acid for the chlorine atom greatly increases the water solubility of degradates relative to the parent compound and contributes to the increased potential for leaching into groundwater. As a result, alachlor ESA and other acetanilide degradation products were listed on the 1998 Safe Drinking Water Act Contaminant Candidate List (CCL). One acetamide and five acetanilde herbicides are currently registered for agricultural use in the U.S. The next step in the CCL-process is to collect data on the concentrations and occurrence of these compounds in the nation's drinking water supplies. However, the existing analytical methods for measuring chloroacetanilide degradates do not address issues specific to analyzing these compounds in drinking water. Because many of the methods were developed for ground water, dechlorination was not addressed nor was the method tested in all types of drinking water matrices. In addition, existing methods do not address all twelve ESA and OA degradates of the six U.S. registered acetanilide/acetamide herbicides. Therefore, the focus of this research was to develop a sensitive and specific analytical method for the analysis of alachlor ESA and other chloroacetanilide degradates in drinking water.