title: Determination of melamine in dairy products using electromembrane-LPME followed by HPLC.
abstract: This study presents the application of electromembrane microextraction technique combined with HPLC-UV detection for fast extraction-preconcentration and determination of melamine in dairy products. It is based on the extraction of charged melamine molecules migrated from 6.5 mL feed solution through a liquid membrane immobilized in the pores of a hollow fiber into 20 μL of the acceptor solution. The best performance was achieved by using 2-nitrophenyloctylether, tris-(2-ethylhexyl) phosphate (10%) and di-(2-ethylhexyl)phosphate (10%) as the extraction solvent; application of a potential of 90 V as the driving force and by adjusting the pH of feed and receiving phases at 5.5 and 1, respectively. The working range was 7-8000 ng mL(-1), with detection limit of 2.0-5.8 ng mL(-1). The enrichment factor was in the range 82-192. Intra- and inter-day relative standard deviations were less than 6.6%. Extraction and relative recoveries for different samples were between 25-59% and 85-95%, respectively.
authors.affiliation: Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, University of Zanjan, 45371-38791 Zanjan, Iran.
authors.forename: Armin
authors.initials: A
authors.lastname: Fashi
authors.affiliation: Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, University of Zanjan, 45371-38791 Zanjan, Iran. Electronic address: yaftian@znu.ac.ir.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Yaftian
authors.affiliation: Environmental Science Research Laboratory, Department of Environmental Science, Faculty of Science, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran.
authors.forename: Abbasali
authors.initials: A
authors.lastname: Zamani
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003611:Dairy Products / Q000032:analysis*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D014227:Triazines / Q000737:chemistry*
chemical_list: D014227:Triazines; C011907:melamine
keywords: Dairy products; Electromembrane microextraction; Melamine; Preconcentration–determination