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ANALYSIS OF ALKYLPHENOLS AND ALKYLPHENOL ETHOXYLATES WITH SEPARATION OF ETHOXYMERS USING REVERSED PHASE LC/MS
Citation:
ROSENBLUM, L. AND K. M. SCHENCK. ANALYSIS OF ALKYLPHENOLS AND ALKYLPHENOL ETHOXYLATES WITH SEPARATION OF ETHOXYMERS USING REVERSED PHASE LC/MS. Presented at Society of Environmental Toxicology and Chemistry (SETAC) Annual Meeting, Montreal, QC, CANADA, November 05 - 09, 2006.
Impact/Purpose:
To inform the public.
Description:
Alkylphenol polyethoxylates are non-ionic surfactants, widely used in detergents, paints, personal care products, etc., which enter the environment primarily through wastewater treatment systems. Their biodegradation during wastewater treatment leads to the formation of persistent metabolites, such as alkylphenol mono- and diethoxylates, alkylphenoxy carboxylates, and alkylphenols, which are present in surface waters. These biodegradation products have been shown to act as endocrine disrupting chemicals (EDCs), leading to concern over the possible presence of EDCs in finished drinking waters. In order to evaluate the efficacy of drinking water treatment processes to remove these alkylphenolic compounds, the analytical method must detect the low analyte levels anticipated post-treatment. An analytical method using C18 solid phase extraction (SPE) followed by LC/MS has been developed for octylphenol (OP), nonylphenol (NP), nonylphenol mono-ethoxylate (NP1EO), nonylphenol di-ethoxylate (NP2EO), octylphenol mono-ethoxylate (OP1EO), octylphenol di-ethoxylate (OP2EO), and nonylphenoxy acetic acid (NP1EC) that permits detection of low levels of the targets in surface and treated waters. The extraction apparatus has exclusively glass and Teflon surfaces to avoid contamination from plastic surfaces that may leach NP. OP1EO, OP2EO, NP1EO, and NP2EO are chromatographically resolved using a commercially available non-endcapped phenyl column. Chromatographic separation eliminates ionization suppression of the poorly ionized mono-ethoxylates by the longer chained ethoxylates, resulting in improved sensitivity for OP1EO and NP1EO. The phenyl column has low retention of humic material resulting in good resolution between target analytes, including NP1EC, and matrix materials extracted from Ohio River water. Instrument detection limits are at or below 20 pg on column for all target analytes. Recoveries are between 75 and 110% when analytes are fortified into reagent water at 100 ng/L.