Development of U.S. EPA Method 559 for the Determination of Nonylphenol and 4-Tert-Octylphenol in Drinking Water by Solid Phase Extraction and LC/MS/MS

Topics in Drinking Water
Oral Presentation

Prepared by D. Tettenhorst, J. Shoemaker
U. S. Environmental Protection Agency, 26 W. Martin Luther King Dr, MS 587, Cincinnati, Ohio, 45268, United States


Contact Information: [email protected]; 513-569-7396


ABSTRACT

The U.S. Environmental Protection Agency’s (EPA) Office of Groundwater and Drinking Water (OGWDW) is responsible for protecting the nation’s drinking water from known and emerging contaminants. OGWDW uses the Drinking Water Contaminant Candidate List (CCL) to identify chemicals that might require future regulation for the protection of drinking water. A key piece of information that must be available to make a regulatory determination is nationwide occurrence data for the contaminants under consideration. OGWDW collects the necessary occurrence data under its Unregulated Contaminant Monitoring Regulations (UCMR). Thus, standardized methods that will produce data of sufficient quality for UCMR monitoring of contaminants are needed.

Nonylphenol and octylphenol are mainly used to produce ethoxylates which are non-ionic surfactants. These surfactants are used in detergents, paints, pesticides, personal care products and plastics. Nonylphenol and 4-tert-octylphenol are potential endocrine disrupting compounds that have been found in surface and ground waters. CCL 4, published in November of 2016, has identified nonylphenol as a contaminant of interest.

Method 559, a solid phase extraction (SPE)-LC/MSMS method, has been developed for nonylphenol and 4-tert-octylphenol. The method addresses issues specific to analyzing compounds in drinking water, such as preservatives, internal and surrogate standards, and aqueous sample and extract holding times. Samples were preserved with sodium bisulfate to inhibit microbial growth and ascorbic acid for dechlorination. Average recoveries of 93.9 - 97.1% with RSDs of ?3.5% in 250 mL of preserved tap water have been obtained using Oasis HLB and Strata-X polymeric SPE cartridges. Precision, accuracy, sensitivity and ruggedness will be demonstrated in deionized water and various tap water matrices, along with aqueous and extract holding time data.