title: Ionic liquid-assisted separation and determination of selenium species in food and beverage samples by liquid chromatography coupled to hydride generation atomic fluorescence spectrometry.
abstract: Different ionic liquids (ILs) were assayed as mobile phase modifiers for the separation and determination of selenite [Se(IV)], selenate [Se(VI)], selenomethionine (SeMet) and Se-methylselenocysteine (SeMeSeCys) by reversed-phase high-performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry (RP-HPLC-HG-AFS). The use of several ILs: 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride ([C6mim]Cl), 1-octyl-3-methylimidazolium chloride, 1-dodecyl-3-methylimidazolium bromide, 1-hexadecyl-3-methylimidazolium bromide and tributyl(methyl)phosphonium methylsulphate was evaluated. Also, the effect of pH, buffer type and IL concentration on the separation of Se species was studied. Complete separation was attained within 12min using a C8column and a gradient performed with a mobile phase containing 0.1% (v/v) [C6mim]Cl at pH 6.0. The proposed method allows the separation of inorganic and organic Se species in a single chromatographic run, adding further benefits over already reported methods based on RP-HPLC. In addition, the influence of ILs on the AFS signals of each Se species was evaluated and a multivariate methodology was used for optimization of AFS sensitivity. The limits of detection were 0.92, 0.86, 1.41 and 1.19μgL-1for Se(IV), Se(VI), SeMet and SeMeSeCys, respectively. The method was successfully applied for speciation analysis of Se in complex samples, such as wine, beer, yeast and garlic.
authors.affiliation: Laboratory of Analytical Chemistry for Research and Development (QUIANID), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Padre J. Contreras 1300, 5500 Mendoza, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
authors.forename: Alexander
authors.initials: A
authors.lastname: Castro Grijalba
authors.affiliation: Laboratory of Analytical Chemistry for Research and Development (QUIANID), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Padre J. Contreras 1300, 5500 Mendoza, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
authors.forename: Emiliano F
authors.initials: EF
authors.lastname: Fiorentini
authors.affiliation: Laboratory of Analytical Chemistry for Research and Development (QUIANID), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Padre J. Contreras 1300, 5500 Mendoza, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina. Electronic address: rwuilloud@mendoza-conicet.gob.ar.
authors.forename: Rodolfo G
authors.initials: RG
authors.lastname: Wuilloud
mesh_terms: D001628:Beverages / Q000032:analysis*; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D052578:Ionic Liquids / Q000737:chemistry; D016566:Organoselenium Compounds / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D012643:Selenium / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D052578:Ionic Liquids; D016566:Organoselenium Compounds; D012643:Selenium
keywords: Atomic fluorescence spectroscopy; Beverage; Food; Ionic liquid; Reversed-phase chromatography; Selenium species