Development of a Drinking Water Method for the Measurement of Select Organic Contaminants in Drinking Water Using Hydrophilic-Modified Polymeric SPE and GC/MS

Poster Presentation

Prepared by P. Grimmett
U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., MS 585, Cincinnati, Ohio, 45268, United States


Contact Information: [email protected]; 513-569-7663


ABSTRACT

In October 2009, the U.S. EPA’s Office of Ground Water and Drinking Water (OGWDW) published its latest Drinking Water Contaminant Candidate List (CCL 3). This list contains potential drinking water contaminants that the agency will consider for regulation. One of the key pieces of information necessary to make a regulatory determination for a contaminant is its nationwide occurrence. Historically, OGWDW has collected the necessary occurrence data under its Unregulated Contaminant Monitoring Regulations (UCMRs). In order for a contaminant to be included in a UCMR, a standardized analytical method for its measurement in drinking water must be available. A group of compounds from CCL 3, which were not amenable to any current EPA method, were evaluated for grouping into a new method. The group consists of two industrial compounds (o-toluidine and quinoline), a pesticide (dimethipin), and a food additive (butylated hydroxyanisole, BHA). The current procedure requires preservation of a 1-L drinking water sample with L-ascorbic acid, EDTA, Trizma buffer, and diazolidinyl urea, followed by solid phase extraction (SPE) with a hydrophilic-modified polymeric (divinylbenzene, 500 mg) sorbent. Sample analyses were then performed using gas chromatography/mass spectrometry (GC/MS). Recovery percentages in all fortified challenge matrices ranged from 71-139% for all compounds, in full scan GC/MS and selected ion mode (SIM). Sample and sample extract holding time studies yielded analyte recoveries within lab data quality objectives (DQOs) of 70-130% over 14 days. Lowest Concentration Minimum Reporting Level (LCMRL) calculations generated for o-toluidine, quinoline, dimethipin, and BHA in SIM were 0.003 µg/L, 0.005 µg/L, 0.003 µg/L, and 0.013 µg/L, respectively. LCMRL values were below the current Health Reference Level (HRL) for each compound.






Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy