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A spectrofluorimetric method for the determination of total selenium in biological samples has been developed. After oxidative destruction, the sample is reacted with a mixture of bromide and 2,3-diamino-1,4-dibromonaphthalene (Br 2 -DAN) without pH adjustment. Selenium(VI) is rapidly reduced by bromide to Se(IV) which then forms 4,7-dibromo-5,6-benzopiazselenol (Br 2 -DAN-Se). The...
Serum is rapidly digested with a mixture of nitric and perchloric acids at a temperature of 180 ± 10°C, and hydrochloric acid is used to reduce selenium(VI) to selenium(IV). Selenium is determined by hydride generation flame atomic absorption spectrometry. The results show that this method has the advantages of being sensitive, accurate, rapid and simple. After the serum is digested and diluted,...
A matrix modifier composed of platinum and nickel is proposed for the determination of selenium in a wild fruit juice made from Lantingguo (Vuccinium uliginosam). Five matrix modifiers (copper/nickel, palladium/magnesium, platinum/magnesium, platinum/nickel and platinum/copper) for suppressing the interference effects of seven co-existing elements (potassium, phosphorus, calcium, magnesium, manganese,...
Quantitation of selenium in plants, soils and sludges was achieved by isotope dilution-mass spectrometry using a benchtop instrument. Samples for analysis were spiked with 76 Se isotope solution. Plant material was digested on a heating block at 150°C using a mixture of nitric acid and hydrogen peroxide. Selenium in soils and sludges was released by treatment with nitric acid followed...
Reaction of selenium with 2,3-diaminonaphthalene was reinvestigated with bromide ion as a catalyst. In acid medium, selenium reacts with the above reagent to form a complex extractable with cyclohexane and with an absorption maximum at 378.5 nm. The molar absorptivity of the complex is 17.5 10 3 1 mol -1 cm -1 . Beer's law is obeyed in the range 0.5-12 mg 1...
An anion exchange HPLC-ICP-MS procedure allowing the simultaneous multielemental speciation analysis of arsenic, selenium, antimony and tellurium has been developed. Four arsenic species (As III , As V , monomethylarsonic acid and dimethylarsinic acid), two selenium species (Se IV and Se VI ) may be determined in a single run as well as one antimony (Sb V )...
A simple, rapid and sensitive flow injection spectrophotometric method for determination of selenium (0.005–1.5 μg ml −1 ) is described. The method is based on the catalytic effect of Se(IV) on the reduction reaction of thionine (TN) with sulphide ion, monitored spectrophotometrically at 598 nm. The detection limit is 5 ng ml −1 the relative standard deviation for eight replicate measurements...
Aqueous solutions and blood plasma spiked with selenite (Se(IV)), selenate (Se(VI)), selenomethionine (SeMet) or trimethylselenonium (TMSe) iodide were analyzed by Zeeman-corrected electrothermal atomic absorption spectrometry (ETAAS) using palladium as a chemical modifier, and by inductively coupled plasma mass spectrometry (ICP-MS). Using ETAAS, the sensitivities for Se(IV), SeMet and TMSe in aqueous...
A new selenite ion selective electrode using solid salts of Ag 2 Se and Cu 2 S has been developed. Detailed information is provided concerning the composition, working pH and conditioning of the electrode. The change of potential with concentration is found to be linear in the range of 10 -5 -10 -2 M, the slope of the linear portion is 28 mV/10-fold change...
A new membrane ion selective electrode sensitive to selenite ion has been developed. The electrode consisted of 1,2-phenylenediamine selen complex PIS (piaselenol) as the active material, PVC or SR (silicon rubber) as membrane matrix and DBF (dibutylphtalate) as plasticizer. This electrode showed linear response for selenite ion in the 10 -5 -10 -1 M concentration range....
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...
A method for the determination of Se in pharmaceutical samples (nutritional supplements and shampoos) is proposed. The method involves two steps: (1) digestion of the samples and reduction of all forms of Se to Se IV , which is complete in only 10 min by the use of a focused microwave digestor; and (2) continuous derivatisation (hydride formation) and spectrometry detection by atomic fluorescence...
The selenium content in blood was determined using the hydrogen catalytic peak. This peak at -1.1 V was obtained in the presence of selenium and molybdenum at pH values of 1-4 in different buffers. For the determination of selenium, the Mo(VI) concentration has to be ~100-200 times higher than the selenium present. The linear domain range of selenium is 1x10 -6 -5x10 -9 M...
In this study a flow injection (FI) system used in conjunction with hydride generation (HG), atomic absorption spectrometry (AAS) and microwave (MW) aided pre-reduction of selenite (Se(IV)) to selenate (Se(IV)) with HCl:HBr has been developed in order to differentiate both inorganic selenium species. As full control of the MW reduction step is possible, the experimental approach allows the use of...
Mineralization procedures for arsenic and selenium analysis are usually limited to wet digestion methods owing to high volatility of these analytes. On the other hand, variable amounts of silicon in some types of samples imply elaborated mineralization procedures to liberate analytes which may be retained in an insoluble residue. Consequently, methods for such material generally include an hydrofluoric...
The presence of selenium in the form of different species in environmental and biological samples receives an increasing attention due to better understanding of its bioavailability, toxicity and transport mechanism. For many years, gas and liquid chromatography have been extensively explored in speciation analysis of this element. Recently, capillary electrophoresis (CE) has made much progress in...
A method for determination of manganese and selenium in serum by simultaneous atomic absorption spectrometry (SIMAAS) is proposed. The samples (30 μl) were diluted (1+3) to 1.0% v/v HNO 3 +0.10% w/v Triton X-100 directly in the autosampler cups. A total of 20 μg Pd+10 μg Mg(NO 3 ) 2 was used as chemical modifier. The pyrolysis and atomization temperatures for the simultaneous...
A simple, accurate, sensitive and selective method is described for rapid determination of ultra-trace quantities of selenium. Selenium (IV) was collected on activated carbon after reduction to elemental Se by l-ascorbic acid. The collected selenium was then determined based on its accelerating effect on the oxidation reaction of methyl orange with bromate in acidic media. Total amount of Se(IV) and...
The effect of pre-reduced Pt and Ir modifiers towards simultaneous determination of As, Se and In in a sodium sulphate matrix was investigated. In spite of application of very isothermal THGA atomizer, negative influence of the matrix is pronounced. The efficiency of iridium modifier is somewhat higher than that of platinum modifier. However compared to palladium modifier both are significantly less...
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