title: Fully automated determination of parabens, triclosan and methyl triclosan in wastewater by microextraction by packed sorbents and gas chromatography-mass spectrometry.
abstract: A fully automated method for the determination of triclosan (TCS), its derivative methyl triclosan (MeTCS) and six parabens (esters of 4-hydroxybenzoic acid) including branched and linear isomers of propyl (i-PrP and n-PrP) and butyl paraben (i-BuP and n-BuP) in sewage water samples is presented. The procedure includes analytes enrichment by microextraction by packed sorbent (MEPS) coupled at-line to large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). Under optimised conditions, compounds were extracted from 2 mL samples, adjusted at pH 3, using a C18 MEPS-sorbent. Adsorbed analytes were eluted directly into the Programmable Temperature Vaporizer (PTV) injector of the chromatograph with 2×25 μL of ethyl acetate. They were quantified using standard solutions in ultrapure water submitted to the same sample enrichment process as real sewage water samples. After signal normalisation using isotopic labelled species as internal surrogates, no differences were noticed among the extraction efficiency for sewage and ultrapure water; moreover, the proposed method reported lineal calibration curves from 0.1 to 10 ng mL(-1), relative standard deviations (%RSD) between 2 and 7.1% and limits of detection (LODs) varying from 0.001 to 0.015 ng mL(-1) in ultrapure water and from 0.02 to 0.59 ng mL(-1) in the most complex sample (raw wastewater).
authors.affiliation: Department of Analytical Chemistry, Nutrition and Food Sciences, Institute for Food Analysis and Research-IIAA, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain. iria.gonzalez@usc.es
authors.forename: Iria
authors.initials: I
authors.lastname: González-Mariño
authors.forename: José Benito
authors.initials: JB
authors.lastname: Quintana
authors.forename: Isaac
authors.initials: I
authors.lastname: Rodríguez
authors.forename: Steffi
authors.initials: S
authors.lastname: Schrader
authors.forename: Monika
authors.initials: M
authors.lastname: Moeder
mesh_terms: D002138:Calibration; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D010226:Parabens / Q000032:analysis* / Q000302:isolation & purification; D012722:Sewage / Q000032:analysis*; D052617:Solid Phase Microextraction / Q000379:methods; D012997:Solvents; D014260:Triclosan / Q000031:analogs & derivatives* / Q000032:analysis* / Q000302:isolation & purification; D014867:Water / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D010226:Parabens; D012722:Sewage; D012997:Solvents; D014874:Water Pollutants, Chemical; D014867:Water; D014260:Triclosan; C502486:methyl triclosan