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A comparison between the performance of three derivatizing reagents (4-chloro-o-phenylendiamine, 4-nitro-o-phenylendiamine and 2,3-diaminonaphthalene) for the analysis of selenite in environmental samples using gas chromatography-mass spectrometry (GC-MS) has been evaluated. The effects of different parameters (pH, temperature and time of derivatization, type and volume of organic solvent and time...
This review deals with liquid phase separation of major arsenic and selenium species followed by element specific detection. It concerns papers published since 1980 and describing only currently used methods that were or could be applied to As and Se speciation in environmental matrices. Methods performances are compared on the basis of efficiency, rapidity, absolute and concentration detection limits...
Silica gel modified with 3-mercaptopropyl-trimethoxysilane was used for the selective separation and pre-concentration of selenite (Se(IV)) from aqueous solutions containing Se(IV) and selenate (Se(VI)). Over a wide range of acidity, from 2 mol l -1 HCl to pH 9.00, Se(IV) was taken up by the mercaptopropyl-silica with nearly 100% efficiency; Se(VI) however was unretained. Se(IV) content...
A simple and economic separation and speciation procedure for selenium in food and water samples have been presented prior to its graphite furnace atomic absorption spectrometry (GFAAS). Magnesium hydroxide coprecipitation system for selenium(IV) was applied to the separation and speciation of selenium ions. The influences of the various analytical parameters for the quantitative recoveries of selenium...
A simple solid phase extraction procedure for speciation of selenium(IV) and selenium(VI) in environmental samples has been proposed prior to graphite furnace atomic absorption spectrometry. The method is based on the solid phase extraction of the selenium(IV)–ammonium pyrrolidine dithiocarbamate (APDC) chelate on the Diaion HP-2MG. After reduction of Se(VI) by heating the samples in the microwave...
The existence of dimethylselenium (DMSe) and dimethyldiselenium (DMDSe) in some environmental samples can cause serious interference on Se(IV) determination by hydride generation atomic fluorescence spectrometry (HG-AFS) due to their contribution on HG-response. A flow injection separation and preconcentration system coupled to HG-AFS was therefore developed by on-line coprecipitation in a knotted...
The optimisation of ICPMS collision/reaction cell conditions for the simultaneous analysis of arsenic and selenium is described. A mixture of 3.8mLmin −1 of H 2 and 0.5mLmin −1 of He was found to be suitable for the removal of both ArAr + and ArCl + interferences. Detection limits down to 30ng (element) L −1 in total analysis, and between 81 and 230ng...
This paper focuses on the analytical performance improvement of the coupled technique HPLC–ICPMS using on-line collision/reaction cell technology for selenium elemental and speciation analyses at the ng (Se) l −1 level in aquatic environment. Collision/reaction cell operating parameters were optimised, resulting in selected conditions of 5.5mlmin −1 H 2 and 0.5mlmin −1...
A non-chromatographic separation and preconcentration method for Se species determination based on the use of an on-line ionic liquid (IL) dispersive microextraction system coupled to electrothermal atomic absorption spectrometry (ETAAS) is proposed. Retention and separation of the IL phase was achieved with a Florisil ® -packed microcolumn after dispersive liquid–liquid microextraction (DLLME)...
A novel adsorbent was developed by coating Mg–FeCO 3 layered double hydroxides (LDHs) on cellulose fibre. The LDHs take up significant amount of selenite and selenate in a wide pH range with similar sorption capacities (pH 3.8–8.0 for selenite and pH 5.8–7.0 for selenate). A mini-column packed with Mg–FeCO 3 LDHs layer coated cellulose fibre particles was incorporated into a sequential...
Sec 2 -containing oligopeptide was synthesized directly from Sec 2 with the traditional liquid phase peptide synthesis without addressing the usually applied and complex solid phase (SPPS) protocol driving through a protected Sec residue and site-oriented oxidation into a diselenide bridge. Effective solubilization of Sec 2 in dimethylformamide and its pH-controlled access...
A simplified speciation method for the determination of selenite, selenate and three selenoaminoacids (selenocystine, selenomethylselenocysteine and selenomethionine) has being developed, based on the coupling of high performance liquid chromatography (HPLC), thermoreduction (TR), hydride generation (HG) and atomic fluorescence spectrometry (AFS). Most of the existing methods based on AFS detection...
A novel method based on dispersive liquid liquid microextraction (DLLME) followed by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) determination was proposed for the speciation of inorganic selenium by using 5-mercapto-3-phenyl-1,3,4-thiadiazole-2-thione potassium salt (Bismuthiol II) as both chelating reagent and chemical modifier. In this method, 500μL ethanol...
A dispersive micro-solid phase extraction (DMSPE) with graphene as a solid adsorbent and ammonium pyrrolidinedithiocarbamate (APDC) as a chelating agent was proposed for speciation and detemination of inorganic selenium by the energy-dispersive X-ray fluorescence spectrometry (EDXRF). In developed DMSPE, graphene particles are dispersed throughout the analyzed solution, therefore reaction between...
Arsenic (As), Selenium (Se) and Mercury (Hg) are three trace elements that have been the subject of much analytical discussion and investigation over the last three decades. While Selenium (Se) is among the list of essential trace elements necessary for the regulation of metabolic processes and overall health, As and Hg are not, and have been the centre of various cases surrounding the contamination...
A novel ultrasound-assisted liquid phase microextraction (UALPME) based on environmental friendly extractants, deep eutectic solvent (DES) was first time presented for speciation of selenium. In present study, five DES solvents of different composition was prepared and used as efficient extractive medium for hydrophobic chelate of Se(IV) with 3,3′-Diaminobenzidine (DAB). The total inorganic Se species...
In this work, ethylenediamine modified poly(glycidyl methacrylate-ethylene dimethacrylate)(poly(GMA-EDMA-NH2)) was prepared for highly selective extraction of Se(VI) with high adsorption capacity of 0.825 mg m−1 (530 µm i.d.). Based on it, a novel method of polymer monolithic capillary microextraction (CME) on-line coupling with inductively coupled plasma-mass spectrometry (ICP-MS) was developed for...
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