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Dive into the research topics where Vasily K. Karandashev is active.

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Featured researches published by Vasily K. Karandashev.


Talanta | 2014

Characterization of size, morphology and elemental composition of nano-, submicron, and micron particles of street dust separated using field-flow fractionation in a rotating coiled column

P. S. Fedotov; Mikhail S. Ermolin; Vasily K. Karandashev; D. V. Ladonin

For the first time, nano- and submicron particles of street dust have been separated, weighted, and analyzed. A novel technique, sedimentation field-flow fractionation in a rotating coiled column, was applied to the fractionation of dust samples with water being used as a carrier fluid. The size and morphology of particles in the separated fractions were characterized by electronic microscopy before digestion and the determination of the concentration of elements by ICP-AES and ICP-MS. The elements that may be of anthropogenic origin (Zn, Cr, Ni, Cu, Cd, Sn, Pb) were found to concentrate mainly in <0.3 and 0.3-1 μm fractions. It has been shown that the concentrations of Cr, Ni, Zn in the finest fraction (<0.3 μm) of street dust can be one order of magnitude higher than the concentrations of elements in bulk sample and coarse fractions. For example, the concentrations of Ni in <0.3, 0.3-1, 1-10, and 10-100 μm fractions were 297 ± 46, 130 ± 21, 36 ± 10, and 21 ± 4 mg/kg, correspondingly. Though the finest particles present only about 0.1 mass% of the sample they are of special concern due to their increased mobility and ability to penetrate into the deepest alveolar area of the lungs. For rare earth elements (La, Ce, Pr, Nd, Sm) that are evidently of natural source and may be found in soil minerals, in contrary, higher concentrations were observed in large particles (10-100 μm). Sc was an exception that needs further studies. The proposed approach to the fractionation and analysis of nano-, submicron, and micron particles can be a powerful tool for risk assessment related to toxic elements in dust, ash, and other particulate environmental samples.


Chemosphere | 2016

Continuous-flow leaching in a rotating coiled column for studies on the mobility of toxic elements in dust samples collected near a metallurgic plant.

P. S. Fedotov; Mikhail S. Ermolin; Alexandr I. Ivaneev; Natalia N. Fedyunina; Vasily K. Karandashev; Yury G. Tatsy

Continuous-flow (dynamic) leaching in a rotating coiled column has been applied to studies on the mobility of Zn, Cd, Cu, Pb, Ni, Sb, As, S, and other potentially toxic elements in atmospherically deposited dust samples collected near a large copper smelter (Chelyabinsk region, Russia). Water and simulated acid rain (pH 4) were used as eluents. The technique enables not only the fast and efficient leaching of elements but as well time-resolved studies on the mobilization of heavy metals, sulphur, and arsenic in environmentally relevant forms to be made. It is shown that up to 1.5, 4.1, 1.9, 11.1, and 46.1% of Pb, As, Cu, Zn, and S, correspondingly, can be easily mobilized by water. Taking into consideration that the total concentrations of these elements in the samples under investigation are surprisingly high and vary in the range from 2.7 g/kg (for arsenic) to 15.5 g/kg (for sulphur), the environmental impact of the dust may be dramatic. The simulated acid rain results in somewhat higher recoveries of elements, except Cu and Pb. The proposed approach and the data obtained can very useful for the risk assessment related to the mobility of potentially toxic elements and their inclusion in the biogeochemical cycle.


Journal of Analytical Chemistry | 2017

Isolation and quantitative analysis of road dust nanoparticles

Mikhail S. Ermolin; P. S. Fedotov; Alexandr I. Ivaneev; Vasily K. Karandashev; Natalia N. Fedyunina; V. V. Eskina

Nanoparticles are capable of preconcentrating various elements, including toxic ones; they have high mobility in the environment and can easily penetrate into a human body. The study of the chemical composition and properties of road dust nanoparticles is an urgent task of analytical chemistry, which needs to be addressed in the monitoring of the anthropogenic load on the environment and the assessment of the potential danger of pollution to human health. In the present paper, we propose a new approach for the isolation, characterization, and quantitative elemental analysis of road dust nanoparticles. Conditions are selected for the separation of nanoparticles from Moscow dust samples by field-flow fractionation in a rotating coiled column; the resulting fractions are characterized by independent methods (using static light scattering and electron microscopy); the method for calculating the concentration of elements in the nanoparticle fraction according to inductively coupled plasma atomic emission spectrometry and mass spectrometry is improved; elements in a water-soluble form are isolated and determined; and the role of soluble organic matter in the binding of trace elements is discussed. It is shown that the total concentration of most elements in the samples of Moscow dust is comparable to the average values for urban soils. Abnormally high concentrations of several elements (Cu, Zn, Ag, Cd, Sn, Sb, Hg, Pb, Tl, and Bi) are revealed in the fraction of nanoparticles; the enrichment factor with respect to the total concentration ranges from 10 to 450. The source of contamination of road dust nanoparticles with copper, zinc, antimony, and cadmium is highly probable wearing-off of brake pads and car tires. The developed procedure of separation, characterization, and analysis of nanoparticles can be used for other polydisperse environmental samples (for example, volcanic ash).


Geochemistry International | 2016

A Set of Analytical Methods for the Estimation of Elemental and Grain-Size Composition of Volcanic Ash

V. M. Shkinev; Mikhail S. Ermolin; P. S. Fedotov; Alexander P Borisov; Vasily K. Karandashev; B. Ya. Spivakov

A combined approach to the analysis of volcanic ash (VA) was proposed. Ash particles were separated by size using a combination of vibration sieving on sieves (140, 70, 40 μm) and field-flow fractionation in a rotating coiled column (for separation of nano- and submicron particles). Initial samples and obtained fractions were characterized using scanning electron microscopy and static light scattering. Their elemental composition was determined using ICP-MS and ICP-AES methods. The radionuclide composition of the VA was studied by the low-background gamma spectrometry. The studies were carried out by the example of ashes from Puyehue volcano, the Puyehue Cordón Caulle volcanic group, Andes (Santiago, eruption on June, 2011), which were taken immediately after eruption and after first rain. It was shown that up to 15% of major elements (such as P, Ca, and К) and trace elements (such as Be, Hg, Tl, As, Sb, and Bi) could be extracted from the ash by rain and migrate into environment. It was also found that the content of radionuclides (U235, Th234, Pb214, Bi214, Be7) after rain decreases by 30–40%. Of special interest are ash nanoparticles (up to 200 nm), in which the contents of Cu, Pb, Tl, Bi, Sn, As, and Sb are over an order of magnitude higher than the bulk contents of these elements in the ash. This regularity was found in samples taken both prior to and after rain. The proposed methodology of fractionation, study, and analysis of ash particles may be applied for a wide range of soil, ash, and dust samples of different nature.


Environmental Science and Pollution Research | 2016

Assessment of elemental composition and properties of copper smelter-affected dust and its nano- and micron size fractions.

Mikhail S. Ermolin; P. S. Fedotov; Alexandr I. Ivaneev; Vasily K. Karandashev; Andrey A. Burmistrov; Yury G. Tatsy

A comprehensive approach has been developed to the assessment of composition and properties of atmospherically deposited dust in the area affected by a copper smelter. The approach is based on the analysis of initial dust samples, dynamic leaching of water soluble fractions in a rotating coiled column (RCC) followed by the determination of recovered elements and characterization of size, morphology and elemental composition of nano-, submicron, and micron particles of dust separated using field-flow fractionation in a RCC. Three separated size fractions of dust (<0.2, 0.2–2, and >2xa0μm) were characterized by static light scattering and scanning electron microscopy, whereupon the fractions were analyzed by ICP-AES and ICP-MS (after digestion). It has been evaluated that toxic elements, which are characteristics for copper smelter emissions (As, Cu, Zn), are accumulated in fraction >2xa0μm. At the same time, up to 2.4, 3.1, 8.2, 6.7xa0g/kg of As, Cu, Zn, Pb, correspondently, were found in nanoparticles (<0.2xa0μm). It has been also shown that some trace elements (Sn, Sb, Ag, Bi, and Tl) are accumulated in fraction <0.2, and their content in this fraction may be one order of magnitude higher than that in the fraction >2xa0μm, or the bulk sample. It may be assumed that Sn, Sb, Ag, Bi, Tl compounds are adsorbed onto the finest dust particles as compared to As, Cu, Zn compounds, which are directly emitted from the copper smelter as microparticles.


Journal of Analytical Chemistry | 2015

Suspension columns with grain sorbents retained in an ultrasonic field for separation and determination of rare-earth elements in wines

R. Kh. Dzhenloda; V. M. Shkinev; T. V. Danilova; Z. A. Temerdashev; Vasily K. Karandashev; B. Ya. Spivakov

The properties of a Diasorb-130-IDK sorbent based on silica gel with a grain size of about 6 µm were studied in order to choose conditions for the separation of the rare-earth elements from the samples of natural wine and their subsequent determination by inductively coupled plasma mass spectrometry. The possibility of the quantitative separation of the elements with the use of an ultrasonic flow suspension column was demonstrated. The results were compared with data obtained with the use of other sample preparation methods. A procedure was proposed for the determination of the rare-earth elements and yttrium in the samples of wines.


Journal of Analytical Chemistry | 2017

Methodology for separation and elemental analysis of volcanic ash nanoparticles

Mikhail S. Ermolin; P. S. Fedotov; Vasily K. Karandashev; V. M. Shkinev

A methodology for separation, characterization, and quantitative elemental analysis of volcanic ash nanoparticles is proposed. A combination of field-flow fractionation in a rotating coiled column and membrane filtration is used in the isolation and separation of nanoparticles. The size and morphology of nanoparticles were studied by static light scattering and scanning electron microscopy. The concentration of major- and trace elements in the bulk sample and the separated fractions was determined by inductively coupled plasma atomic emission spectrometry and mass spectrometry. It is shown that the total concentrations of most elements in the ash sample are comparable to their average concentrations in the Earth’s crust. On the other side, in the fraction 50–100 nm, the concentrations of Ni, Zn, Ag, Sn, Sb, Pt, Tl, Pb, and Bi are one or two orders of magnitude higher than their total concentrations, which probably indicates the preconcentration of corresponding elements from volcanic gases by nanoparticles. In the fraction represented by water-soluble forms of elements and nanoparticles smaller than 50 nm, Cu, Zn, Pb, and several other elements are found; the partition of elements between the solution and solid phase (nanoparticles) is assessed. The proposed methodology requires further development and application to the analysis of volcanic ash from various regions of the Globe.


Journal of Analytical Chemistry | 2018

Analysis of Niobium–Rare-Earth Ores by Inductively Coupled Plasma Mass Spectrometry

Vasily K. Karandashev; A. M. Zybinsky; V. P. Kolotov; S. V. Kordyukov; V. A. Simakov; T. V. Orlova

To determine the composition of niobium–rare-earth ores by atomic emission spectrometry and inductively coupled plasma mass spectrometry, two procedures are developed for sample preparation based on autoclave decomposition and flux fusion. Autoclave decomposition is carried out in a mixture of HF and HNO3 at a temperature of up to 220°C and a pressure of up to 160 atm using a developed system with resistive heating. Subsequent evaporation to dry salts ensures the removal of F– ions and silicon as SiF4. The residue is dissolved in a mixture of HCl and H2O2 at 160°C under elevated pressure. The resulting solutions (10% with respect to HCl with the addition of H2O2) are diluted before measurements. The dissolution process is monitored for each sample using stable highly enriched isotopes of 91Zr, 100Mo, 149Sm, and 178Hf. The second procedure is based on fusing samples with a mixture of Na2CO3 and Na2B4O7 at 1050°C in a muffle furnace and dissolving the resulting melt in a mixture of HCl and H2O2. The procedures were tested using the national (NFS-23) and foreign standard samples of composition (OREAS-462, 463, 464, 465, Australia) and real samples of niobium–rare-earth ores.


Environmental Chemistry Letters | 2018

Unexpected behavior of Zn, Cd, Cu, and Pb in soils contaminated by ore processing after 70 years of burial

P. S. Fedotov; Rustam Kh. Dzhenloda; Bayarma V. Dampilova; Svetlana G. Doroshkevich; Vasily K. Karandashev

Heavy metals in contaminated ore processing areas present a risk of contamination of waters and life. Therefore, the most mobile fractions of metals, which can be xa0evaluated by chemical extraction, require a special research attention. Classicalxa0reports using batchwise extraction methods are debatable in terms of real metal availability because naturally occurring processes are always dynamic. Therefore, herexa0we used dynamic extraction in a rotating coiled column in orderxa0to mimic natural conditions. We studied Cu, Pb, Zn, and Cd in soils and sand wastes from a tungsten–molybdenum plant. Soils hadxa0been buried under tailing dumps during 70xa0years. Exchangeable and acid-soluble fractions were separated using 0.05xa0M Ca(NO3)2 and 0.43xa0M CH3COOH, respectively. Results show that mobility, availability, and vertical transport of metals are surprisingly different. Specifically, there is nearly no mobile exchangeable Zn in wastes, whereas all studied soil horizons are characterized by elevated Znxa0concentrations, up to 0.6xa0g/kg. Cd behaves like Zn. The concentration and mobility of Cu vary with depth. The upper humus horizon contains up to 2.1xa0g/kg of exchangeable Cu. The behavior of Pb is quite particular: xa0soils are nearly free from lead, though its total concentration in wastes may reach 3.9xa0g/kg. To the best of our knowledge, such unusualxa0variations in the behavior of heavy metals have not been reported before.


Chemosphere | 2018

A contribution of nanoscale particles of road-deposited sediments to the pollution of urban runoff by heavy metals

Mikhail S. Ermolin; P. S. Fedotov; Alexandr I. Ivaneev; Vasily K. Karandashev; Natalia N. Fedyunina; Andrey A. Burmistrov

Road-deposited sediments (RDS) present a sink for traffic-related pollutants including heavy metals (HMs). HMs associated with RDS particles enter the urban aquatic environment during rainfall events and have adverse effects for biota. RDS nanoscale particles (NSPs) require special consideration due to their specific properties, extremely high mobility in the environment, and ability to penetrate into living organisms. In the present work, the contribution of NSPs of RDS to the pollution of urban runoff by HMs has been evaluated for the first time. It has been shown that bulk RDS samples are polluted by HMs as compared to background urban soils (geo-accumulation indexes of Cu and Zn may attain 2-3). Meanwhile, NSPs of RDS are enriched by HMs as compared to bulk samples; concentration factor for Ni, Cu, Zn, Cd, Sn, and Pb in NSPs being varied from 2 to 10. The water-soluble fractions of RDS samples were also analyzed. Results have shown that the content of water-soluble HMs in RDS is insignificant and rarely exceeds 0.5% of the total contents of HMs in the bulk samples; the highest contents are identified for Cu and Pb. It should be noted that the water-soluble fraction is nearly free from Zn and this element is almost entirely present as particulate matter (NSPs). In general, the overall contribution of NSPs and water-soluble fraction of HMs to the pollution of urban runoff is comparable.

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P. S. Fedotov

Russian Academy of Sciences

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Mikhail S. Ermolin

Russian Academy of Sciences

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Alexandr I. Ivaneev

National University of Science and Technology

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V. M. Shkinev

Russian Academy of Sciences

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Natalia N. Fedyunina

National University of Science and Technology

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B. Ya. Spivakov

Russian Academy of Sciences

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R. Kh. Dzhenloda

Russian Academy of Sciences

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Yury G. Tatsy

Russian Academy of Sciences

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