title: Focused ultrasound solid-liquid extraction of perfluorinated compounds from sewage sludge.
abstract: A method for the determination of perfluorocarboxylic acids (PFCAs) and perfluorooctanesulfonic acid (PFOS) in sewage sludge based on focused ultrasound solid-liquid extraction (FUSLE) and reverse-phase ultra-performance liquid chromatography (UPLC) coupled to quadrupole-time of flight mass spectrometry (QTOFMS) has been developed. FUSLE is a fast, low-cost and efficient extraction technique based on the application of high power focused ultrasonic waves using a micro-tip immersed directly in the extraction mixture. For the method development, the extraction solvent was studied and afterwards the factors affecting the extraction efficiency were optimised by means of a central composite design. Optimal FUSLE conditions were: 8 mL of acetonitrile as extraction solvent and an ultrasonic irradiation power of 65% for only 20s. Two extraction cycles were enough for the quantitative extraction of PFCs from sewage sludge. Limits of detection below 0.2 ng g(-1) (dry sewage sludge), relative standard deviation values less than 8% and recovery values between 69 and 104% were found for the target analytes. Finally, the method was applied to the analysis of sewage sludge samples from several wastewater treatment plants of La Rioja.
authors.affiliation: Department of Chemistry, University of La Rioja, La Rioja, Spain. maria-pilar.martinez@unirioja.es
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Martínez-Moral
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Tena
mesh_terms: D002853:Chromatography, Liquid; D005466:Fluorocarbons / Q000032:analysis*; D059625:Liquid-Liquid Extraction / Q000295:instrumentation / Q000379:methods*; D012722:Sewage / Q000032:analysis*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D012997:Solvents / Q000737:chemistry; D013016:Sound; D053719:Tandem Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D005466:Fluorocarbons; D012722:Sewage; D012997:Solvents; D014874:Water Pollutants, Chemical