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Several sample extraction techniques have been evaluated in order to obtain highest selenium (Se) extraction efficiency in two types of selenium-enriched plants (Allium sativum and Brassica juncea). Three extracting solutions have been studied for this purpose: 0.1M HCl, 25mM ammonium acetate buffer (pH 5.6) and protease in aqueous solution. In each case, the effect of the ultrasonic probe during...
A method has been developed for mercury speciation in water by using columns packed with Chlorella vulgaris immobilised on silica gel. The method involves the retention of CH 3 Hg + and Hg 2+ in micro-columns prepared by packing immobilised algae in polypropylene tubes, followed by selective and sequential elution with 0.03 and 1.5M HCl for CH 3 Hg + and Hg...
The feasibility of static secondary ion mass spectrometry (S-SIMS) for the detection of molecule specific information from complex materials, such as natural clay and soil samples, has been investigated. Ion trap (IT), as well as triple quadrupole (TQ) instruments, have been used for mass analysis. Secondary ion images have been acquired using time-of-flight (TOF) S-SIMS. The generation of molecular...
In this study, a new technique by hydride generation–atomic fluorescence spectrometry (HG–AFS) for determination and speciation of inorganic arsenic using multisyringe flow injection analysis (MSFIA) is reported. The hydride (arsine) was generated by injecting precise known volumes of sample, a reducing sodium tetrahydroborate solution (0.2%), hydrochloric acid (6M) and a pre-reducing solution (potassium...
A new preservation method has been proposed for the speciation of As(III) and As(V) in acid mine drainage (AMD) samples, characterised by low pH and high metallic content. Samples were taken from a polymetallic sulphides mining area in the province of Huelva (SW Spain), under exploitation until the 1960s for its Cu, Pb and Zn sulphides. The abandoned mine works and the numerous waste rocks heaps produce...
Aerosol particles have important effects on human health, climate, regional visibility, and the deposition of acidic and toxic substances. The aerosols also have significant pharmaceutical and industrial applications. Trials of gas chromatographic analysis of extracts composition of diesel exhaust particles and aerosol mass spectrometer measurement of diesel exhaust particles composition are introduced...
Vanadium(IV) and vanadium(V) were easily separated from each other in the same plant sample and be determined independently by ETAAS (electrothermal atomic absorption spectrometry). This was achieved by treating the sample with 1M (NH 4 ) 2 HPO 4 which transfer only insoluble V(V) species into solution leaving V(IV) species in the solid part of the sample solution. V(IV) was...
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 method using bi-directional electrostacking (BDES) in a flow system is presented for As preconcentration and speciation analysis. Some parameters such as electrostacking time and applied voltage, support buffers and their concentrations were investigated. Boric acid plus sodium hydroxide at 0.1mol/l concentration was selected as support buffer to improve the pre-concentration factor (PF) for As(V)...
This paper describes a new procedure for the determination of Sb (III) and Sb (V) by differential pulse adsorptive stripping voltammetry (DPAdSV) using pyrogallol as a complexing agent. The selection of the experimental conditions was made using experimental design methodology. The detection limits obtained were 1.03×10 −10 and 9.48×10 −9 moldm −3 for Sb (III) and Sb (V), respectively...
In this work, a simple preconcentration system, achieved by replacing the sample tip of the autosampler arm by a micro-column packed with Amberlite IRA-910 or silica gel chelating resin functionalised with 1,5-bis(di-2-pyridyl)methylene tbiocarbohydrazide (DPTH-gel), is developed for the determination of Sb(V) and total antimony, respectively. Different factors including pH of sample solution, ionic...
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...
For separation and determination of vanadium(IV/V) species, a fast and sensitive method by combining hollow-fibre liquid phase microextraction (HF-LPME) with electrothermal vaporization (ETV)-ICP-OES has been developed. Two vanadium species (V(IV) and V(V)) were separated by HF-LPME with the use of ammonium pyrrolidinecarbodithioate (APDC) as chelating agent for complexing with different V species...
An integrated approach for the accurate determination of total, labile and organically bound dissolved trace metal concentration in the field is presented. Two independent automated platforms consisting of an ultraviolet (UV) on-line unit and a chelation/preconcentration/matrix elimination module were specifically developed to process samples on-site to avoid sample storage prior to inductively coupled...
Complex matrices and rather high acidity in environmental samples are often the impelling challenges for the used running buffers of capillary electrophoresis. Twelve binary acid–base buffers were evaluated for separation of Cr(VI)/Cr(III), Co 2+ and Zn 2+ in a sample containing various salts by capillary electrophoresis with contactless conductivity detector. The malic acid (MA) systems...
A sequential arsenic extraction method was developed that yielded extraction efficiencies (EE) that were approximately double those using current methods for terrestrial plants. The method was applied to plants from two arsenic contaminated sites and showed potential for risk assessment studies. In the method, plants were extracted first by 1:1 water–methanol followed by 0.1M hydrochloric (HCl) acid...
The toxic properties of tungsten compounds have recently been brought to the forefront with clusters of human cancer cases, such as in Fallon, NV. Such instances have made the determination of tungsten in natural water supplies vitally important. Tungsten exists in most environmental matrices as the soluble and mobile tungstate anion, although it can polymerize with itself and other anions, such as...
A flow injection system with anion exchange resin minicolumns was coupled with dynamic reaction cell (DRC™) ICP-MS for the determination and speciation of selenite and selenate at sub μgL −1 levels. The charged selenate and uncharged selenite were separated on the first resin column in which only selenate was retained. The unretained selenite was then deprotonated with alkaline solution, and...
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