Entity

Time filter

Source Type


Pribylova G.A.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Journal of Radioanalytical and Nuclear Chemistry | Year: 2011

Influence of ionic liquids (ILs) addition (1-50 wt%) on extraction efficiency of actinides by diphenyl(dibutyl)carbamoylmethylphosphine oxide (Ph2Bu2) from 3 M HNO3 has been studied. Am(III) distribution ratios in two-phase systems 0.1 M Ph2Bu 2 in either DCE or CHCl3-3 M HNO3 depending on the nature of additional ionic liquids: imidazolium-based ILs: [C 4mim][PF6], [C4mim][BF4] and phosphonium-based ILs: PPF6, PBF4 and PCl were determined. The highest value of Am(III) extraction ratio change (1040) was found on addition of PPF6 to Ph2Bu2 in CHCl3. Extraction of Pu(IV) and U(VI) by 0.001 M Ph2Bu2 in the presence of [C4mim][PF6] in DCE, CHCl3 or meta-nitrobenzotrifluoride (NBTF) have been investigated. The greatest enhancement of extraction efficiency was observed using CHCl3, the least polar studied solvent. Using a mixture of conventional solvent and ionic liquid as a solvent for extractant enables one to increase distribution ratios and reduce viscosity of organic phase as compared with ionic liquid viscosity. The marked increase of Am(III), Pu(IV) and U(VI) extraction extent by Ph 2Bu2 on addition of ionic liquids to the extent of 10 wt% permit one essentially to diminish amounts considerably more expensive carbamoylmethylphosphine oxide(the general name is CMPO) used in TRUEX process. © 2011 Akadémiai Kiadó. Source


Korobova E.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Journal of Geochemical Exploration | Year: 2010

The distribution of iodine (Ι) has been studied in the main environmental components (soils and soil microorganisms, ground water and dominating plant species) and in the food chain (drinking water, forage and cow's milk) in the geochemically different areas of the non-chernozem zone of the Russian plain.The mean I concentration in the parent rocks ranged from 0.19 ± 0.04. mg/kg (dry weight, dw) to 5.0 ± 1.87. mg/kg depending on the origin and texture of the rock and the presence of carbonates. The element content in the watershed soils distinctly depended upon the organic matter content, the origin and composition of the parent rock, the age of the landscape and the humidity. Watershed sandy soddy podzolic soils of the young fluvioglacial ("polesje") and moraine landscapes were most lacking in I (≤0.5. mg/kg, dw). However, the adjacent flood plain soils of the subordinated landscapes were 6 to 23 times richer in I due to secondary accumulation. Therefore, flood plain soils could contribute to the I supply of the local food chain. Biomass of the soil microorganisms played an important role in I accumulation containing from 0.01% to 3.24% of the total I incorporated in the top 20. cm soil layer. Iodine content in the water varied between 0.2 μg/l and 21.0 μg/l reaching maximum values in the ground water of organic soils and in the artesian water with enhanced salinity. In river and lake water I amount increased in the presence of soluble organic substances or carbonates. The accumulation of I in plants depended upon the total I content in the soil as well as systematic and ecological peculiarities of the plant species. The maximum I concentration was found in lichens and mosses which had 1.08 ± 0.19. mg/kg and 0.74 ± 0.10. mg/kg (dw), respectively. Hydrophyte species were enriched in I as compared to meso- and xerophyte species. Iodine accumulation in cow hair was related to I content in local soils and rocks. In fluvioglacial and moraine landscapes it was 2 to 3 times less than in the areas of the eluvium of carbonate loess-like and Permian rocks (0.13-0.18. mg/kg and 0.24-0.54. mg/kg, respectively). The study showed the possibility of estimating the general I status of farm animals by I content of their hair. Landscape geochemical approach proved to be a fast and effective method of evaluation of spatial I variation, depending upon the geochemical structure of the non-chernozem zone of the Russian plain.Areas of sandy moraine and fluvioglacial deposits covered by soddy podzolic sandy soils may be treated as I deficient biogeochemical provinces where I prophylaxis is most essential. Flood plain areas and other accumulative landscapes, artesian water and hydrophytes contribute to I supply of the local food chains. On the other hand, the latter areas and plants, when subjected to radioiodine contamination, need monitoring due to the enhanced I transfer to the food chains. © 2010 Elsevier B.V. Source


Timerbaev A.R.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Electrophoresis | Year: 2010

This review article represents the sixth in a series of reviews on CE applied to inorganic analysis, appearing in this journal, and focuses on material published in 2007-2008. As a fundamental review, it examines primarily those documents in which the emphasis is on advances in general CE methodology which are traditionally set on the attainment of higher detection sensitivity and greater preconcentration factors both in capillary and microchip separation formats. Following a major research trend of the previous review period (see A.R. Timerbaev, Electrophoresis 2007, 28, 3420-3425), publications focusing on the quantification of different element species continue to rapidly outpace other applications. A range of practicable separation and detection designs tailor-made to species-selective analysis are critically discussed in order to assess their impact on the rate of development and wide acceptance of CE in the field. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA. Source


Timerbaev A.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Sturup S.,Copenhagen University
Current Drug Metabolism | Year: 2012

Contemporary medicine increasingly relies on metal-based drugs and correspondingly growing in importance is the monitoring of the drugs and their metabolites in biological samples. Over the last decade, a range of analytical techniques have been developed in order to improve administration strategies for clinically approved compounds and understand pharmacokinetics, pharmacodynamics, and metabolism of new drugs so as ultimately to make their clinical development more effective. This paper gives an overview of various separation and detection methods, as well as common sample preparation strategies, currently in use to achieve the intended goals. The critical discussion of existing analytical technologies encompasses notably their detection capability, ability to handle biological matrices with minimum pretreatment, sample throughput, and cost efficiency. The main attention is devoted to those applications that are progressed to real-world biosamples and selected examples are given to illustrate the overall performance and applicability of advanced analytical systems. Also emphasized is the emerging role of inductively coupled plasma mass spectrometry (ICP-MS), both as a standalone instrument (for determination of metals originating from drug compounds) and as an element-specific detector in combinations with liquid chromatography or capillary electrophoresis (for drug metabolism studies). An increasing number of academic laboratories are using ICP-MS technology today, and this review will focus on the analytical possibilities of ICP-MS which would before long provide the method with the greatest impact on the clinical laboratory. © 2012 Bentham Science Publishers. Source


Timerbaev A.R.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Timerbaev R.M.,The Russian Center for Policy Studies Center
TrAC - Trends in Analytical Chemistry | Year: 2013

This article reviews recent applications of the method for actinide-speciation analysis, with emphasis on using capillary-electrophoresis-separation schemes integrated with inductively coupled plasma mass-spectrometry detection. Also brought into focus are studies in which the speciation information acquired is complemented by relevant thermodynamic data on complexation of actinides with naturally-occurring ligands. © 2013 Elsevier Ltd. Source

Discover hidden collaborations