title: Rapid liquid chromatography-tandem mass spectrometry-based method for the analysis of alcohol ethoxylates and alkylphenol ethoxylates in environmental samples.
abstract: A sensitive and selective method for the determination of alcohol ethoxylates (AEOs) and alkylphenol ethoxylates (APEOs) using solid-phase extraction (SPE) and LC-MS/MS was developed and applied to the analysis of water samples. All AEO and APEO homologues, a total of 152 analytes, were analyzed within a run time of 11min, and the MS allowed for the detection of ethoxymers containing 2-20 ethoxy units (nEO=2-20). The limits of detection (LOD) were as low as 0.1pg injected, which generally increased as nEO increased (e.g., as high as 300pg for nEO=20). Additionally, the responses of the various ethoxymers varied by orders of magnitude, with ethoxymers with nEO=3-5 being the most sensitive and those with nEO>15 producing the least response in the MS. Absolute extraction recoveries of the analytes ranged from 37% to 69% in ultrapure water (RSD≤20%), with the recovery depending on the length of the alkyl chain. Abiotic stability studies were performed, and C14-18 ethoxylates showed significant degrees of degradation. Water samples from the Colorado River were then analyzed for AEOs and APEOs, with absolute extraction recoveries ranging from 33% to 45% (RSD≤12%). The predominant species observed in most samples were the octylphenol (OP) and nonylphenol (NP) ethoxylates, which contained total concentrations that were greater than 100ng/L APEOs in a couple samples. Other AEO homologues were identified in the river water samples, including C13, C15, C16, and C18 ethoxylates, but these compounds were generally present at much lower levels (i.e., <50ng/L total concentration).
authors.affiliation: USA Environmental Protection Agency, Office of Research and Development, National Exposure Laboratory, Environmental Sciences Division, 944 East Harmon Avenue, Las Vegas, NV 89119, USA. dearmond.patrick@epa.gov
authors.forename: Patrick D
authors.initials: PD
authors.lastname: DeArmond
authors.forename: Amanda L
authors.initials: AL
authors.lastname: DiGoregorio
mesh_terms: D000438:Alcohols / Q000032:analysis*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D010636:Phenols / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000438:Alcohols; D010636:Phenols; D014874:Water Pollutants, Chemical
keywords: Alcohol ethoxylates; Alkylphenol ethoxylates; Liquid chromatography–tandem mass spectrometry; Nonionic surfactants; Solid-phase extraction