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A coupling of thin layer chromatography with laser ablation ICP SF MS was developed for the fractionation of Ni, V, Fe and S in crude oil and its fractions (saturate, aromatic, resin and asphaltene). The detection limits were 18ngg −1 and 23ngg −1 for nickel and vanadium, respectively, and a sample could be characterized in terms of the metal distribution as a function of species polarity...
For the identification of human exposure to one of the most toxic compounds, which is methyl mercury (MeHg + ), fingernail clippings were selected as the matrix of interest. Within this pilot study, six samples from different origins and from people with different food consumption patterns were chosen.Species-analysis of MeHg + was performed according to the following procedure: dissolution...
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...
No previous analytical procedures are available and validated for mercury speciation analysis in terrestrial animal tissues. This analysis is a difficult task both because the expected concentrations are low, since important accumulation process are not likely to occur, and also because there are not commercially available certified reference material. Thus, an analytical methodology has been developed...
A sensitive and selective method for the preconcentration and speciation of sub ngL −1 levels of chromium species in aqueous solutions with high salt contents is described. The developed method is based on temperature-controlled microextraction of chromium species using the 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF 6 ]) ionic liquid as an extractant followed by electrothermal...
An innovative technique for rapid identification and quantification of mercury (Hg) species in soils and sediments was developed using a direct mercury analyser. Speciation was performed by the continuous thermal-desorption of mercury species (temperature range 76–770°C), in combination with atomic absorption spectrophotometry detection. Standard materials HgCl 2 , Hg bound to humic acids...
A polyacrylamide hydrogel containing the Chelex-100 resin has traditionally been used as the binding agent for the diffusion gradients in thin films (DGT) technique. The Chelex-100 resin, although important for the determination of various transition metals, is unsatisfactory for the determination of alkaline earth metals, particularly Ba. In this paper, a cellulose membrane, treated with phosphate...
In the present study, a flow injection system using dual mini-columns, SiO 2 /Al 2 O 3 /TiO 2 and silica gel functionalized with [3-(2-aminoethylamino)propyl] trimethoxysilane (SiO 2 /AAPTMS) for the sequential preconcentration of Cr(III) and Cr(VI), respectively, from water samples with FAAS detection was proposed. A two-level full factorial design (2 4...
A miniaturized solid phase extraction procedure has been developed for ultra-trace determination of inorganic arsenic species. Arsenic(III) as pyrrolidinedithiocarbamate complex was selectively adsorbed on 30mg poly(hydroxyethyl methacrylate) (PHEMA) micro beads, which is simply packed into a micro-pipette-tip. The adsorbed arsenic was quantitatively eluted by 700μL 0.25M NH 3 and determined...
A new method was developed for the speciation analysis of inorganic arsenic in coal samples by high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry after microwave-assisted extraction. Effective extract of As(III) and As(V) in coal sample was achieved by 1.0molL −1 H 3 PO 4 and 0.1molL −1 ascorbic acid. Under the optimized...
In the framework of trace element analysis by Q ICP-MS in a simulated deep Callovo-Oxfordian groundwater, separation procedures based on extraction chromatography were developed to eliminate the high salt contents and to concentrate Zr and U simultaneously. Theoretical and experimental speciation studies showed the importance of adjusting the medium to HNO 3 /HF (0.5M/0.005M) to guarantee...
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 speciation system for antimony (III) and antimony (V) ions that based on solid phase extraction on tetraethylenepentamine bonded silica gel has been established. Antimony was determined by graphite furnace atomic absorption spectrometry (GF-AAS). Analytical conditions including pH, sample volume, etc., were studied for the quantitative recoveries of Sb (III) and Sb (V). Matrix effects on the recovery...
In the present study, we evaluated a commonly employed modified Bureau Communautaire de Référence (BCR test) 3-step sequential extraction procedure for its ability to distinguish forms of solid-phase Pb in soils with different sources and histories of contamination. When the modified BCR test was applied to mineral soils spiked with three forms of Pb (pyromorphite, hydrocerussite and nitrate salt),...
Silver is recognized as an important pollutant of natural waters. This element is a selective tracer of anthropogenic pollution related to sewage. Studying its bio-availability requires the application of specific separation of the free ion. A liquid membrane is proposed for separating Ag + from estuarine water samples.A bulk liquid membrane (BLM) has been selected. Free silver is transported...
A simple, sensitive and efficient method of ultrasound-assisted emulsification of solidified floating organic drop microextraction (USE-SFODME) coupled to electrothermal atomic absorption spectrometry for the speciation of antimony at different oxidation state Sb(III)/Sb(V) in environmental samples was established. In this method, the hydrophobic complex of Sb(III) with sodium diethyldithiocarbamate...
A rapid and relatively clean method for determining six organotin compounds (OtC) in textile goods with a gas chromatograph equipped with a conventional flame photometric detector (GC-FPD) has been developed. After the reflux-extraction to use methanol containing 1% (v/v) of hydrochloric acid, five hydrophobic OtC (e.g. tributyltin: TBT) and slightly less hydrophobic dibutyltin (DBT) could be drawn...
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...
In this research a new method was developed and optimized for the determination of Sb(V) and Sb(III) in human erythrocytes fractions (plasma and cytoplasm) by high performance liquid chromatography with hydride generation atomic fluorescence spectrometry. The method considers the first step of samples cleaning by protein precipitation by salting out followed by C18 solid phase extraction, EDTA elution,...
A microextraction procedure for the speciation of very low concentrations (0.005–0.2µgL −1 ) of chromium is discussed. To the aqueous sample (10mL), diluted hydrochloric acid, sodium chloride and a small amount of tributylphosphate (80µL) are incorporated, and the mixture is submitted to ultrasounds for 10min. The organic phase recovered after centrifuging is injected into the electrothermal...
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