Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry with the preliminary hydride generation (HG-ICP-OES) techniques were used for the determination of chalcophile elements in sulfide-bearing rocks after different sample pretreatment. As and Se in the hydrochloric acid leaching solutions could not be determined neither by quadruple MS with correction equations, no by high resolution (HR-MS) (R= 10,000) due to high C-HCl/C-As Se ratio. Se, Sn, Ga, Bi, Te, Sb, Ge, Cd, Tl and Pb in hydrochloric acid leaching solutions can be determined by ICP-MS, and As, Se, Sn, Bi, Te and Sb by HG-ICP-OES. Main matrix elements - Co, Ni, Fe, Cu - don't affect the signal of analytes in case of ICP-MS method. The matrices of the sulfide ores and rocks were shown to significantly suppress the signals of the all elements using HG-ICPOES techniques. To eliminate the influence of matrix components, the use of auxiliary reagents - 5% (m/V) KI and 0.5% (m/V) ascorbic acid C6H8O6 as well as 5% (m/V) KBr - has been proposed. Optimal conditions for obtaining the hydrides and for the determination of hydride-forming elements by HG-ICP-OES were established. Addition of KI and ascorbic acid mixture allows the determination of As, Sn, Bi and Sb. Six elements - Se, Te, As, Sn, Bi and Sb could be determined in the presence of 5% (m/V) KBr. The C-min values for the determination of these elements by ICP-MS and HG-ICP-OES methods are comparable and vary between 0.01 and 0.02 mu g g(-1) for As, Se, Sb and Bi, and between 0.05 and 0.1 mu g g(-1) for Sn and Te.
The capabilities of the ICAP-6500 Duo high-resolution echelle spectrometer (Thermo Scientific) for the elemental analysis of geochemical materials and extraterrestrial matter have been investigated. The features of the determination of elements in chondritic meteorites are studied, and appropriate procedures, including sample preparation, are developed. Main (including phosphorus and sulfur) and impurity elements are determined in four fragments of chondritic meteorites: Kainsaz, Zhovtnevyi Khutor, Saratov, andAllende. The data are compared with the average concentration of elements in ordinary chondrites. The composition of the available sample of the Allende chondritic meteorite is characterized for using it as an intralaboratory reference sample.
The paper presents data on the possibility of ETAAS analysis, and a technique of this analysis, of salt rocks, their insoluble residues, and organic fractions from these rocks for Au, Pt, and Pd (concentrations from 10–7 to 10–2 ppm). Various techniques for the decomposition of the samples are discussed, and the paper presents information on the extent of Au, Pt, and Pd adsorption from chloride complexes when the POLYORGS-IV complex-forming adsorption agent is applied. The determined atomization parameters of the elements in a graphite furnace are reported. Precious metals are proved to be concentrated in the insoluble residues of the salt rocks and in the slimes (salt wastes) when the salt rocks are processed. The forms in which precious metals are contained in the salt-bearing rocks are determined.
A new approach to template synthesis of mesostructured pH-sensitive SiO2 nanocontainers is developed. The approach combines the stages of synthesis of the nanocontainers and their loading with a targeted functional substance. The structure, capacity, and the rate of "unloading" of the nanocontainers at different pH values of an aqueous medium under static and quasi-dynamic conditions are studied using mesoporous SiO2 nanoparticles as a model. Nanoparticles are synthesized using the micelles of cetyltrimethylammonium bromide as templates. Based on the obtained information, a mechanism is proposed for release of cetyltrimethylammonium cations from SiO2 nanocontainers into the aqueous medium.
Possibilities of the determination of Au, Ag, and Si in dispersions of nanoparticles and biological samples by inductively coupled plasma atomic absorption and atomic emission spectrometry are demonstrated. Conditions of complete sample mineralization and the quantitative transfer of gold and silver to solution are found. The parameters of analyte determination in flame, graphite furnace, and plasma are optimized. The completeness of the atomization of gold, silver, and silicon in plasma on the introduction of nanoparticles as colloidal solutions is estimated. The conducted research allowed the estimation of the degree of gold and silver reduction at different stages of synthesis of composite nanoparticles with the core/shell structure. Quantitative information on the dynamics of accumulation and the redistribution of composite nanoparticles with gold or silver shells in organs and tissues of mices after the intravenous administration of colloidal solutions of nanoparticles.
Drinkable waters in Bryansk oblast are generally poor in I and Se. Possible I and Se speciation in the drinkable waters and their means of migration and concentration in soils at geochemically contrasting conditions are analyzed, and the possible reason for the high mobility of I is demonstrated to be predetermined not only by its occurrence in the form of iodide and organic complexes but also by solute mineral species (CaI+ and MgI+), with the former and the latter types of the complexes spread more widely in the polessky and opolny landscape types, respectively. Iodine complexation with alkali-earth cations under reduced neutral-weakly alkaline conditions facilitates, on the one hand, vertical iodine migration and, on the other hand, its precipitation on the carbonate barrier. The predominant solute species of Se in these environments is hydroselenide, which can form FeSe in the presence of significant Fe concentrations and be precipitated on the reduced barrier in soils of hydromorphic landscapes. The generally low total I and Se concentrations in the drinkable waters and the migration of solute compounds of radioactive I in the form of organic and inorganic complexes could likely result in a higher thyroid morbidity rate over the whole territory of Bryansk oblast, including areas contaminated with radioactive I isotopes after the accident at the Chernobyl nuclear power plant.
ICP-AES. Multielement preconcentration with separation of matrbc is an effective solution of this problem. Electrothermal atomic absorption (ETAAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and off-line sorption preconcentration have been used for the development of new sensitive and selective methods of heavy metals determination in the salts and waste brines. Measurements were carried out using atomic absorption spectrophotometer Perkin-Elmer Zeeman/3030 Model with HGA-600 electrothermal atomization system, for multielement measurements the ICP AES polychromator Jarrell Ash İCAP 9000 was used. Device for flow İnjection sorption preconcentration BPI (Aquita, Russia) with 4 micro columns packed with DETATA sorbent (aminocarboxylic on polysterene base) was used for separation and preconcentration of heavy metals. There are many factors that influence effective FI preconcentration: content of salts, sorption and desorption flow rates, sorption and desorption times (ore volumes of the sample and eluent), pH, acid concentration in eluent, kind of eluent, ete. The parameters of simultaneous multi-element sorption, elution, and signal registration have been optimized. The parameters of flow sorption ICP AES analysis of the samples with complex matrices were investigated and the analytical procedure for simultaneous determination of Cd, Zn, Pb, Cu, Ni, Mn, V, Ti, Al by ICP-AES in industrial brines and salts was developed. For routine laboratories methods of ETAAS determination of elements in concentrate solutions are developed and proposed for validation as Standard methods. Usİng reference brines the bias, precision and accuracy of methods were determined according to Standard Procedure for Certifıcation of Measurement Methods. Sensitivity of proposed methods is better for the factor of 1 0 1 0 0 than that for the certifıed methods used in salt industry now.
Показано, что питьевые воды Брянской области, в целом, обеднены йодом и селеном. Рассмотрены возможные формы нахождения йода и селена в питьевых водах и особенности их миграции и концентрирования в почвах в геохимически контрастных условиях. Показано, что высокая подвижность йода может обуславливаться миграцией не только в форме йодида и органических комплексов, но и в виде минеральных растворенных в воде комплексных форм (CaI+ и MgI+); при этом первый тип комплексных соединений более распространен в ландшафтах полесского типа, а второй в условиях опольных ландшафтов. В почвах комплексообразование йода с щелочноземельными катионами в восстановительных нейтрально-слабощелочных условиях с одной стороны, способствует миграции йода по вертикальному профилю, а с другой стороны, осаждению йода на карбонатном барьере. В тех же условиях доминирующей водорастворимой формой селена является гидроселенид, который в присутствии значительного количества железа может трансформироваться в минеральную фазу FeSe и фиксироваться на восстановительном барьере в почвах подчиненных гидроморфных ландшафтов. Высказано предположение, что общее низкое содержание йода и селена в питьевых водах и водная миграция радиоактивных изотопов йода в виде комплексных органических и минеральных соединений могло способствовать более выраженной заболеваемости щитовидной железы на всей территории Брянской области, в том числе и загрязненной после аварии на Чернобыльской АЭС радиоактивными изотопами йода.
Aggregative stable dispersions of particles with anisotropic cores of iron(III) oxyhydroxide and gold or silver nanoshells are synthesized. They feature maximum plasmonic absorption at about 1000 nm (i.e., in the “optical window” of biological tissues). Such composite particles are of considerable interest for their potential use in cancer therapy. The possibility of finely tuning the position of localized surface plasmon resonance to the required wavelength is demonstrated for the FeOOH core/Au(Ag) shell nanostructures through a controlled variation of the metal shell thickness with a very small step (up to 1 nm). The surface modification of such composite particles by polyethylene glycol (PEG) considerably enhances the aggregative stability of their aqueous dispersions. Quantitative information about the distribution dynamics of the PEG-conjugated composite FeOOH core/Au shell particles in various organs and tissues of tumor-bearing mice has been obtained after an intravenous injection of a colloid solution of these particles. It is shown that composite particles can remain for a rather long time in a bloodstream without aggregation; moreover, their accumulation in a tumor takes place. Preliminary in vivo experiments have shown that PEGylated FeOOH core/Au(Ag) shell particles are effective thermosensibilizers in the pulse laser therapy of tumors.
A comprehensive technique for determining Ni and V in crude oils in a wide range of their concentrations is described. The procedure involves ETAAS, ICP-AES, and autoclave sample preparation. The optimal conditions for the mineralization of oil samples in Ankon-AT2 analytical autoclaves in a mixture of HNO3 and H2O2 are found. Oil and condensates of oil- and gas-bearing basins are taken as objects of investigation. The concentrations of Ni and V in these systems are estimated and the regularities in the distributions of Ni and V are revealed.