title: Ion-pair sorptive extraction of perfluorinated compounds from water with low-cost polymeric materials: polyethersulfone vs polydimethylsiloxane.
abstract: A method for the determination of seven perfluorinated carboxylic acids and perfluorooctane sulphonate (PFOS) in aqueous samples using low-cost polymeric sorptive extraction as sample preparation technique, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination has been developed and validated. Simplicity of the analytical procedure, low volume of solvent and sample required, low global price and a good selectivity providing cleaner extracts are the main advantages of this extraction technique. Polydimethylsiloxane (PDMS) and polyethersulfone (PES) materials were evaluated and compared to achieve the best extraction efficiencies. Hence, different variables have been optimized, viz.: sample pH, concentration of an ion-pairing agent (tetrabutylammonium), ionic strength, sample volume, extraction time, desorption solvent volume, desorption time and the need for auxiliary desorption techniques (sonication). Overall, PES leaded to a better sensitivity than PDMS, particularly for the most polar compounds, reaching detection limits (LODs) in the 0.2-20 ng L(-1) range. The precision of the method, expressed as relative standard deviation (RSD), was lower than 16%. Finally, the PES material was employed for the analysis of sea, sewage and fresh water samples. Perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) were detected in all the analyzed influent samples reaching levels of up to 401 ng L(-1). In surface water, perfluorohexanoic acid (PFHxA) exhibited the highest concentrations, up to 137 ng L(-1).
authors: Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors: Eugenia
authors: E
authors: Villaverde-de-Sáa
authors: Inés
authors: I
authors: Racamonde
authors: José Benito
authors: JB
authors: Quintana
authors: Rosario
authors: R
authors: Rodil
authors: Rafael
authors: R
authors: Cela
mesh_terms: D000327:Adsorption; D017738:Alkanesulfonic Acids / Q000032:analysis*; D002264:Carboxylic Acids / Q000032:analysis*; D002853:Chromatography, Liquid; D004129:Dimethylpolysiloxanes / Q000032:analysis*; D005466:Fluorocarbons / Q000032:analysis*; D007477:Ions / Q000737:chemistry; D011108:Polymers / Q000032:analysis*; D013450:Sulfones / Q000032:analysis*; D013499:Surface Properties; D053719:Tandem Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D017738:Alkanesulfonic Acids; D002264:Carboxylic Acids; D004129:Dimethylpolysiloxanes; D005466:Fluorocarbons; D007477:Ions; D011108:Polymers; D013450:Sulfones; D014874:Water Pollutants, Chemical; C022840:polyether sulfone; C013830:baysilon; C076994:perfluorooctane sulfonic acid