title: Application of hollow cylindrical wheat stem for electromembrane extraction of thorium in water samples.
abstract: In this study, wheat stem was used for electromembrane extraction (EME) for the first time. The EME technique involved the use of a wheat stem whose channel was filled with 3 M HCl, immersed in 10 mL of an aqueous sample solution. Thorium migrated from aqueous samples, through a thin layer of 1-octanol and 5%v/v Di-(2-ethylhexyl) phosphate (DEHP) immobilized in the pores of a porous stem, and into an acceptor phase solution present inside the lumen of the stem. The pH of donor and acceptor phases, extraction time, voltage, and stirring speed were optimized. At the optimum conditions, an enrichment factor of 50 and a limit of detection of 0.29 ng mL(-1) was obtained for thorium. The developed procedure was then applied to the extraction and determination of thorium in water samples and in reference material.
authors.affiliation: Department of Chemistry, University of Zabol, P.O. Box 98615-538, Zabol, Iran. Electronic address: m_khajeh@uoz.ac.ir.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Khajeh
authors.affiliation: School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Stig
authors.initials: S
authors.lastname: Pedersen-Bjergaard
authors.affiliation: Department of Chemistry, University of Zabol, P.O. Box 98615-538, Zabol, Iran.
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Barkhordar
authors.affiliation: Department of Biology, University of Zabol, P.O. Box 98615-538, Zabol, Iran.
authors.forename: Mousa
authors.initials: M
authors.lastname: Bohlooli
mesh_terms: D002412:Cations / Q000737:chemistry; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D055664:Electrochemical Techniques / Q000295:instrumentation; D006863:Hydrogen-Ion Concentration; D007492:Iran; D008567:Membranes, Artificial; D008670:Metals / Q000737:chemistry; D018547:Plant Stems; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D013910:Thorium / Q000032:analysis / Q000302:isolation & purification*; D014908:Triticum; D014875:Water Pollutants, Radioactive / Q000302:isolation & purification
chemical_list: D002412:Cations; D008567:Membranes, Artificial; D008670:Metals; D012997:Solvents; D014875:Water Pollutants, Radioactive; D013910:Thorium
keywords: Electromembrane extraction; Thorium; Water samples; Wheat stem