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Kuban P.,Tallinn University of Technology | Timerbaev A.R.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Electrophoresis | Year: 2012

This article is the seventh in a series examining biannually the methodological developments in the field of CE analysis of inorganic species and covers relevant documents published between January 2009 and December 2010. Following an analysis of the significant accomplishments that have impacted the field in two recent years, a survey of advances in general CE methodology is presented. Subsequently, several notable trends that can be perceived in this well-established field are discussed: the continuing rise of ME and consequent development of suitable detection techniques, most notably contactless conductivity detection, the constant pace of advances in speciation analysis, and an increase in non-analytical CE applications to study complexation and (bio)transformation reactions of metal analytes. A range of recently emerged multi-detection designs, ICP-MS interface devices, and separation systems, for which outpacing work has been conducted, are also brought into focus. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 315.27K | Year: 2012

The Arctic is changing rapidly, and it is predicted that areas which are today tundra will become tree-covered as warming progresses, with, for example, forest spreading northwards to the coast of northern European Russia by 2100. In some parts of the Arctic, such as Alaska, this process, commonly referred to as greening, has already been observed over the past few decades; woody shrubs are expanding their distribution northwards into tundra. Such vegetation changes influence nutrient cycling in soils, including carbon cycling, but the extent to which they will change the storage or release of carbon at a landscape scale is debated. Nor do we fully understand the role that lakes play in this system although it is known that many lakes in the tundra and northern forests are today releasing carbon dioxide and methane into the atmosphere in significant amounts, and a proportion of this carbon comes into the lake from the vegetation and soils of the surrounding landscape. Lakes form an important part of arctic landscapes: there are many thousands of them in our study areas in Russia and west Greenland, and they act as focal points for carbon cycling within in the wider landscape. It is vital that we understand the interactions between plants, soils, nutrients, and lakes because there are massive carbon stores in the high northern latitudes, particularly in frozen soils, and if this carbon is transferred into the atmosphere (as carbon dioxide (CO2) or methane) it will create a positive feedback, driving further global warming. For this reason, the Arctic represents a critical component of the Earth System, and understanding how it will it respond to global environmental change is crucial. Lakes are a key link in this process. As lakes are tightly coupled with terrestrial carbon cycling, changes in the flows of carbon to a lake are faithfully recorded in lake sediment records, as are changes in the biological processing of that carbon within the lake. We also know that similar vegetation changes to those observed or predicted today occurred in the past when climate was warmer than today, and thus past events can provide an analogue for future changes. This project will examine lake sediment records, using techniques that extract a range of chemical signals and microscopic plant and animal remains, to see how vegetation changes associated with past natural climate warming, such as migration of the tree-line northwards, affected lake functioning in terms of the overall biological productivity, the species composition, and the types of carbon processing that were dominant. Depending upon the balance between different biological processes, which in turn are linked to surrounding vegetation and soils, lakes may have contributed mostly to carbon storage or mostly to carbon emissions ?at a landscape scale. Changes in vegetation type also influence decomposition of plant remains and soil development, and this is linked to nitrogen cycling and availability. Nitrogen is an important control over productivity and hence of carbon fixation and storage, and thus it is important to study the dynamics of nitrogen along with those of carbon. Due to the spatial variability of climate and geology, the pace of vegetation development (and of species immigration) and the types of plants involved have not been uniform around the Arctic. By examining several lakes in each of three regions (Alaska, Greenland, Russia) we will be able to describe a broad range of different vegetation transitions and the associated responses of the lakes. Our results can be used to inform our understanding of the likely pathways of recently initiated and future changes. They can also be up-scaled to the whole Arctic and so contribute to the broader scientific goal of understanding feedbacks to global warming.

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.

Timerbaev A.R.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Chemical Reviews | Year: 2013

The CE (Capillary Electrophoresis) method and technology has undergone several important developmental phases. Typical capillary electrolytes are low-conductivity buffer solutions, no extreme pHs being involved, and thus often compatible with the matrix (native) surroundings of element species. The advantage of using such separation hardware and media is that it prevents the species from losing integrity in the CE system. As a consequence of the flat flow profile resulting from CE, no mass transfer between phases, and negligible latitudinal diffusion in capillaries, the analytes are separated as sharp zones. This enhances the CE separation efficiencies and hence makes the number of species separated in one run greater than that achieved in HPLC. Another aspect relevant to multidisciplinary collaborations involving CE methodology developers is related to the fact that CE, as of course is the case any other single technique, does not meet every challenge in speciation analysis. The next generation instrumentation should therefore benefit from advances in pertinent analytical fields.

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.

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.

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.

Timerbaev A.R.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Journal of Analytical Atomic Spectrometry | Year: 2014

Drug discovery and development is a long, expensive, and multiplex process, most of the steps (if not all of them) are unfeasible without use of different analytical techniques. In the case of metal-based drugs, their preclinical development and clinical testing increasingly rely on ICP-MS, having no-match analytical features in this seemingly 'killer' application. Applied with the standalone or combined (hyphenated) setup, the method allows robust, sensitive, and precise determinations of drug-comprising metals as well as specific and often multielemental detection of the biomolecular metabolic forms. This analytical information is invaluable for the assessment of drug-like properties, metabolite fingerprinting and profiling, monitoring the drug-biomolecule interactions, cellular uptake and pharmacokinetic studies, etc. but above all, for a better understanding of a drug's mechanisms of delivery and action. This review is mainly focused on the emerging role and current challenges of ICP-MS-based methodology in the field. Consistently with the title matter, special emphasis is placed on investigational metal-containing compounds that not only exhibit certain pharmacological or diagnostic properties but also hold promise of being advanced to (or already entered) clinical studies. It also provides a brief outlook of how the potential of ICP-MS is to be exploited in the future so as to accelerate the metallodrug development and reduce the enormous accompanying costs. This journal is © the Partner Organisations 2014.

Timerbaev A.R.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
TrAC - Trends in Analytical Chemistry | Year: 2016

There is still high anticipation among oncology metallodrug developers that a real breakthrough can be gained due to substituting platinum, as a principal component of all approved metal-based chemotherapeutics, with another metal such as arguably second in importance ruthenium. Such expectations have directed research activities to improvements in the molecular design, with varying the ruthenium oxidation state and bonding type, and to the better understanding of the basic underlying chemistry and biochemical mechanisms of cytotoxicity. It is the latter issue where the metallomic approaches have received growing attention as indispensable to decipher the metabolic pathways, to shed light on modes of delivery and action, and to identify active, toxic species and potential cell targets of metallodrugs. Therefore, there is obviously a need to critically evaluate recent progress due to using metallomic strategies and techniques to advance the preclinical development of anticancer ruthenium agents. Being aware that the rate of failure for ruthenium compounds is no less than for other molecular entities tested and tending to be overwhelming, the author places the focus of this review on merely (H2ind)[RuIIICl4(Hind)2] (Hind = 1H-indazole) and Na[RuIIICl4(Hind)2], often referred to as KP1019 and NKP-1339, respectively, the only ruthenium drug candidates presently in clinical trials, (H2im)[RuIIICl4(DMSO)(Him)] (Him = 1H-imidazole), NAMI-A, which has though been recently suspended of clinical testing, as well as on Ru(η6-toluene)(pta)Cl2 and RuII(η6-p-cymene)(pta)Cl2 (pta = 1,3,5-triaza-7-phosphaadamantane), or RAPTA-T and RAPTA-C, respectively, the lead investigational compounds of the RAPTA family. © 2016 Elsevier B.V.

Slyuta E.N.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry
Solar System Research | Year: 2013

A review is given of the mineralogical and chemical composition of iron meteorites and the problems associated with their origin. A detailed discussion is presented of the physical and mechanical properties of iron meteorites and their dependence on the structure, chemical composition, and temperature. Iron meteorites are shown to characterize, with no distortions, the physical and mechanical properties of their parent bodies (metallic asteroids). The population of M-type asteroids and the main characteristics of the identified metallic asteroids are examined. Compared with iron meteorites, metallic asteroids have a different shape and are not fragments of larger metallic parent bodies. The estimates for the current deviatoric stress in metallic asteroids show that, since their formation, asteroids have not been heated to over 600°C and certainly have not been subjected to partial or complete melting. An empirical dependence is found of the critical dimensions of small metallic objects (which allow for gravitational deformation) on the yield strength at temperatures below 300 K. It is shown that the physical and mechanical data are also a strong argument against the hypothesis of the origin of iron meteorites and metallic asteroids from the iron core of a differentiated parent body. © 2013 Pleiades Publishing, Ltd.

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