title: Analysis of n-alkanes at sub microgram per liter level after direct solid phase microextraction from aqueous samples.
abstract: This work describes the application of the previously presented solid phase microextraction (SPME) fiber in direct mode for sampling of C10-C20 n-alkanes from aqueous solution. The fiber has simple composition and is constructed from activated charcoal:PVC suspension in tetrahydrofuran. When the composition of the fiber was optimized that the optimum composition was 90:10 (activated charcoal:PVC) for direct mode, whereas it was 75:25 for sampling from the headspace of aqueous samples. This fiber is completely stable in contact with water. The extraction efficiency is improved in the presence of 0.1 M NaCl. The value is between 17.8-38.5% for the first extraction, which better than the efficiency of similar commercial fibers. After seven extractions, all analytes are removed from the aqueous samples nearly 100%. Single fiber repeatability and fiber-to-fiber reproducibility are good and both are less than 13% for all studied alkanes. Finally, direct mode SPME was used in the determination of n-alkanes in the range of sub microg L(-1) without any additional preconcentration procedure. Gas chromatography along with flame ionization detection were used for separation and detection of the studied analytes.
authors.affiliation: Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran. farajzade@yahoo.com
authors.forename: Mirali
authors.initials: M
authors.lastname: Farajzadeh
authors.forename: Mehdi
authors.initials: M
authors.lastname: Hatami
mesh_terms: D000473:Alkanes / Q000032:analysis*; D002606:Charcoal; D007700:Kinetics; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods*; D011143:Polyvinyl Chloride; D015203:Reproducibility of Results; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D000473:Alkanes; D014873:Water Pollutants; D014867:Water; D002606:Charcoal; D011143:Polyvinyl Chloride