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In the present work, a simple and highly sensitive analytical methodology for determination of Tl + and Tl 3+ species, based on the use of modern and non-volatile solvents, such as ionic liquids (ILs), was developed. Initially, Tl + was complexed by iodide ion at pH 1 in diluted sulfuric acid solution. Then, tetradecyl(trihexyl)phosphonium chloride ionic liquid (CYPHOS ...
Arsenic is ubiquitous in the tissues of marine organisms and in uncontaminated environments it is dominantly present as the highly soluble and easily extractable non-toxic arsenical, arsenobetaine. However in contaminated environments, higher proportions of inorganic arsenic, which is much less soluble, are accumulated into the tissues of marine organisms, resulting in lower extraction efficiencies...
Mercury is a toxic compound that can contaminate humans through food and especially via fish consumption. Mercury's toxicity depends on the species, with methylmercury being the most hazardous form for humans. Hg speciation analysis has been and remains a widely studied subject because of the potential difficulty of preserving the initial distribution of mercury species in the analysed sample. Accordingly,...
A thiophene–coumarin hybrid molecule, (6E)-6-((thiophen-2-yl)methyleneamino)-2H-chromen-2-one (TMC) has been prepared and its single crystal X-ray structure is reported. TMC can selectively detect Cr 3+ in presence of other common cations. Both TMC and its Cr 3+ complex are well characterized by different spectroscopic techniques like 1 H NMR, QTOF-MS ES + , FTIR and...
A simple solid phase extraction system based on the applying the nickel–aluminum layered double hydroxide (Ni–Al LDH) as a nano-sorbent was developed for the speciation analysis of chromium and manganese by flame atomic absorption spectrometry (FAAS). The method is based on the fact that Cr(VI) and Mn(VII) oxyanions could be adsorbed on the Ni–Al(NO 3− ) LDH and/or exchanged with LDH...
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...
A flow injection method of analysis has been developed for the simultaneous determination of V(IV) and V(V) using the difference in the rate of complex formation between vanadium in two different oxidation states and Xylenol Orange in acidic media. The proposed method used a spectrophotometric detector equipped with two flow cells aligned with the same optical path to yield two successive peaks per...
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...
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