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:

Acetanilide herbicides are frequently applied in the U.S. on crops (corn, soybeans, popcorn, etc.) to control broadleaf and annual weeds. The acetanilide herbicides currently registered for use in the U.S. are: alachlor, acetochlor, metolachlor, propachlor, dimethenamid and flufenacet. Acetanilide degradation products are generally more water soluble and mobile than the parent herbicide, thus there is greater potential for these degradates to be found in ground waters and surface waters. The most common acetanilide degradation products reported in the literature are the ethanesulfonic acid (ESA), oxanilic acid (OA) and sulfinylacetic acid (SAA) derivatives of the parent herbicides. The ESA and OA degradates of alachlor, metolachlor, and acetochlor have been reported in U.S. Midwestern surface and ground waters at typical concentrations of 0.1- 20 micrograms per liter.

High priority is given to this research project in the U.S. EPA's Office of Research and Development because acetanilide degradation products are identified on the 1998 Drinking Water Contaminant Candidate List (CCL). As part of the assessment process to determine whether these contaminants should ultimately be regulated, national occurrence data must be collected by the Office of Ground Water and Drinking Water (OGWDW) under the Unregulated Contaminant Monitoring Rule. Thus, analytical methodology suitable for gathering occurrence data for acetanilide degradation products in drinking water is needed and will be developed in this task and delivered to OGWDW. While several methods have been reported in the literature, these methods do not address issues specific to analyzing these compounds in drinking water. Many of the methods are for ground waters or surface waters, so dechlorination and preservation issues are not addressed. In addition, none of the methods reported in the literature contain all the ESA and OA degradates of the U.S. registered acetanilide herbicides. However, the solid phase extraction (SPE) and liquid chromatography/mass spectrometry (LC/MS) methodology reported in the literature will be the starting point for the methodology developed in the NERL.

Record Details:

Record Type:PROJECT

Projected Completion Date:04/30/2005

OMB Category:Other

Record ID: 18331

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Project Information:

Progress :Research under this task has been completed with the development of U.S. EPA Method 535 entitled "Measurement of Chloroacetanilide and Other Acetamide Herbicide Degradates in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)". This task remains open only to complete a second journal article for submission to J. of AOAC International by March 2005 describing the final stages in the development of U.S. EPA Method 535.

The draft method was sent out for peer review in August, 2004. As a Category II research product, the draft method was sent to two internal peer reviewers (within the U.S. EPA) and three external peer reviewers. One internal reviewer was from the Office of Research and Development, and one from the Office of Ground Water and Drinking Water (OGWDW). The draft method was sent out for peer review accompanied by a charge letter explaining the reason for the method development, and the areas that the review should cover. All peer reviews were received back by September 7, 2004. The peer review comments were addressed and the final method sent to Cynthia Dougherty in OGWDW on September 29, 2004.

In addition to Method 535, a research summary document was completed which provides supplemental information not contained in the method. This document underwent the same peer reviewed process described above and will be delivered to David Munch in OGWDW in November, 2004.

Relevance : This research is driven by the 1996 Amendments to the Safe Drinking Water Act. Specifically, acetanilide pesticide degradation products are identified on the 1998 Contaminant Candidate List. The U.S. EPA needs occurrence data and treatment data in order to make a regulatory decision on these compounds. However, the EPA currently does not have a drinking water method for these acetanilide degradation products. Before occurrence data can be acquired in the next UCMR by OGWDW, a rugged research method must be developed. Therefore, analytical methods development for these compounds has been given high priority. This method and the occurrence data gathered with it will provide critical information to be used in creating better U.S. EPA regulations and policies for protecting humans from CCL chemicals in U.S. drinking water supplies.

On-going contact has been established with OGWDW to keep each other aware of current methods progress and future requirements. OGWDW currently expects another UCMR no earlier than late FY04 and this method should be ready well before then. In addition, contact has been established with the engineers in NRMRL responsible for evaluating treatment technologies for alachlor ESA in an effort to provide each other with valuable information. Finally, the PI has established contacts in the scientific community through recent attendance/presentation at a national conference. As a result of this contact, a mini-symposium was initiated by Monsanto and USGS to informally discuss analytical methodology issues related to the determination of acetanilide degradates. The PI attended and presented, along with 11 other researchers in the field, at the mini-symposium on October 16, 2001 in St. Louis.

Clients :Office of Ground Water and Drinking Water (Dave Munch, Hiba Shukairy, Valerie Blank, Kesha Forrest)

Research Component :CCL (CHEMICAL)

Risk Paradigm :EXPOSURE

Project IDs:

ID Code :none

Project type :ORD-DW Plan

ID Code :5885

Project type :OMIS