title: Trace analysis of hydrophobic micropollutants in aqueous samples using capillary traps.
abstract: Studying the fate of persistent organic pollutants (POPs) in glacier environments scientist face the challenge of snow and ice samples, in which concentrations of these pollutants are at the ultra-trace level and the amount of sample available is often very limited. We have improved an extraction method for hydrophobic organic pollutants such as polychlorinated biphenyls (PCBs) in aqueous media to meet the requirements of these challenging samples. It is based on partitioning of the analytes from the water into the polydimethylsiloxane (PDMS) coating of an open tubular-fused-silica capillary. By comparison with conventional liquid-liquid extraction, we validated the method for six indicator PCBs, covering a wide range of polarity. The new method has very low detection limits of 10-20pg/L for the investigated PCBs, a small uncertainty between 9% and 37%, depending on concentration, and requires a small sample volume of less than one liter. Further, it is characterized by easy handling and reduced organic solvents consumption. The method is comparatively insensitive to contamination, reproducible, and suitable for a wide range of applications.
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Testing and Research, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland; PSI, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland; Oeschger Centre for Climate Change Research, University of Berne, Berne, Switzerland.
authors.forename: Pavlina Aneva
authors.initials: PA
authors.lastname: Pavlova
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Testing and Research, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Schmid
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Testing and Research, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Zennegg
authors.affiliation: Institute for Chemical and Bioengineering, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Bogdal
authors.affiliation: PSI, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland; Oeschger Centre for Climate Change Research, University of Berne, Berne, Switzerland; Department of Chemistry and Biochemistry, University of Berne, Berne, Switzerland. Electronic address: margit.schwikowski@psi.ch.
authors.forename: Margit
authors.initials: M
authors.lastname: Schwikowski
mesh_terms: D057927:Hydrophobic and Hydrophilic Interactions; D007053:Ice / Q000032:analysis; D059625:Liquid-Liquid Extraction / Q000295:instrumentation / Q000379:methods; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000737:chemistry; D012914:Snow / Q000737:chemistry; D014867:Water / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D007053:Ice; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D014867:Water; D011078:Polychlorinated Biphenyls
keywords: Aqueous samples; GC–MS; Micropollutants; PDMS; POPs