Using atomic emission spectrometry with inductively coupled plasma and flame version of atomic absorption spectrometry, methods for determining the content of Co, Cr, Ti, V in a wide concentration range from 1·10–3 to n·10 % in tungsten carbide-based materials without matrix separation and using certified solid standard samples with good metrological characteristics were developed. The relative standard deviation is 0.05 – 0.005 when the content of elements is from 1 to 20 % and does not exceed 0.15 when the content of elements is from 0.001 to 0.1 %. Depending on the chemical, phase and disperse composition, as well as the method of obtaining tungsten carbide-based compounds that form different types of materials, which are very different in their ability to dissolve, various sample preparation schemes were used. The analytical parameters for the determination of Co, Cr, Ti, V were found, the operating conditions of the spectrometers were optimized, and calibration methods were selected. The influence of the tungsten matrix element on the analytical signals of analytes and ways of taking it into account have been studied. The possibilities of using spectroscopic methods for the determination of Co, Cr, Ti, V are compared. It is shown that the ICP AES method is dominant in the determination of elements in the concentration range from 1·10–3 to n·10 % in materials based on tungsten carbide. The proposed methods of analytical control will provide research on the creation of new materials based on tungsten carbide, including nanostructured ones, with extremely high physical and mechanical properties, which is especially important in the context of import substitution of materials.

A technique has been proposed for flame photometry determination of lithium additions and calcium, a major component, in the synthesis of novel hydroxyapatite (HA) based materials in order to find relationships between synthesis conditions, the composition of the material, and its functional properties. Ceramic samples were prepared via coprecipitation with the use of lithium carbonate, followed by calcination at 1300°C. We synthesized materials containing 0.25 to 1 at

A method for quantification of lithium additives and calcium as a sample base component during synthesis of new materials based on hydroxyapatites (HA) using flame atomic emission spectroscopy is proposed to reveal a connection in the chain «synthesis conditions — composition — functional properties». Ceramic samples were obtained by co-deposition using Li carbonate and calcination at 1300°C. The materials were synthesized with a lithium content of 0.25 to 1 at.%, some of the samples were synthesized with the co-addition of cerium Ce(NO 3 ) 3 from 0.25 to 1 at.%. The method of additives and reference solutions were used to determine Li in HA samples. The determination of calcium was carried out in separate aliquots after 50-fold dilution. It is shown that the determination of lithium at concentrations of 0.1 mg/liter by flame photometry in hydroxyapatite solutions is possible with S r of 0.1. It is shown that it is difficult to dope the material with lithium by co-precipitation from solutions, while heat treatment during synthesis does not affect the result. It is proposed to use joint doping of the material with lithium and cerium, while at least 0.25 at.% Li is included in the HA structure. The developed technique can be used to determine lithium and calcium using a flame photometer PFA 378 at all stages of the synthesis of new materials based on HA.

Abstract—This paper studies the chemical composition stability of modified 1 mol

Calculated and experimental mass spectra (at temperatures region of 1100-1500 K) of alkali metals tungstates are presented. Vapor pressures and thermodynamic characteristic of gaseous alkali metal tungstates are determined.

A polydisperse iron oxide nanopowder consisting of hematite α-Fe2O3 and magnetite Fe3O4 has been synthesized by solid-state reduction of iron hydroxide Fe(OH)3. The obtained iron oxide nanopowder has been used to prepare aqueous suspensions with a particle dispersion of 100–400 nm in the concentration range of 0.25–1.25 mg/L. The bioactivity of the iron oxide nanopowder has been evaluated using the pre-sowing treatment of Zéa máys corn seeds. The effect of the nanopowder on the germination ability and energy of the seeds and the plant root length has been studied. The treatment with nanoparticles has been found to stimulate the development of the plant organism and make it possible to enhance germination by 15

Boron-containing brushite cements (B-BC) for bone grafting based on B-substituted β-tricalcium phosphate (B-TCP) have been developed. The phase composition and microstructure of B-BC have been studied. It is shown that the crystalline phase of brushite is formed as a result of hardening of cements. The behavior of B-BC in physiological solution containing TRIS-buffer was studied. The strength of B-BC under compression 5 days after mixing is 22.5 ± 1 MPa. Studies of antibacterial activity against gram-negative strain E. coli ATCC25922 and gram-positive strain S. aureus ATCC25923 showed that boron containing brushite cement exhibits antibacterial activity against both strains, causing a decrease in the number of CFU after 3 h of incubation. In vitro studies of the developed B-BC were carried out, it was shown that the developed cements based on TCP and B-TCP are biocompatible and promising for use in bone tissue surgery.

Unsubstituted tricalcium phosphate (TCP) and Mn/Sr-cosubstituted TCP have been prepared by solid-state synthesis at 1200°C. The synthesized compounds have been characterized by X-ray diffraction, IR spectroscopy, and scanning electron microscopy. The results indicate that solid-state synthesis of TCP and Mn,Sr-TCP yields compounds with the whitlockite structure. We have determined their lattice parameters and demonstrated the incorporation of the manganese and strontium ions into the structure of TCP.

An approach to the determination of the composition of novel biocompatible materials based on cerium-containing calcium phosphates by TXRF is proposed. The ranges of analyte contents in solutions for the correct determination of Ca, P, Ce by the external standard method were determined. A systematic underestimation of the calcium signal at a Ca content in the analyzed composite sample above 30 mg/liter is noted. The Compton scattering spectra for the ceramic sample solution were analyzed to assess the compliance of the sample with the thin layer criterion, the maximum value was 16. 8 keV (96°). According to the graph of the mass attenuation coefficient for a film of a given composition, the attenuation of the calcium line is not related with the absorption effect of the sample. The internal standards (Gd and Cu) were selected and conditions for the determination of micro- and macro-components in solutions and suspensions of samples were determined. It is shown that with a calcium content up to 50 mg/liter in the sample, it is possible to determine correctly Ca, P, and Ce by TXRF method in solutions and suspensions with S r 0.05 and 0.09, respectively. The convergence of the results obtained is noted by the methods of external and internal standards with appropriate dilutions of solutions and suspensions.

A polydisperse nanopowder of iron oxide, consisting of hematite α-Fe2O3 and magnetite Fe3O4, was obtained by the method of solid-phase reduction of iron hydroxide Fe(OH)3. On the basis of the obtained iron oxide nanopowder, aqueous suspensions were prepared in the concentration range of 0.25 – 1.25 mg/l with a particle dispersion of 100 – 400 nm. To assess the biological activity of iron oxide nanopowder, pre-sowing treatment of corn seeds Zéa máys was carried out. It has been established that the treatment with nanoparticles has a stimulating effect on the development of the plant organism, making it possible to achieve an increase in germination by 15% and root mass by 23%. Determination of the quantitative content of iron in different parts of the plant was carried out using atomic emission and atomic absorption spectroscopy. It was shown that as a result of treatment of plants with iron nanoparticles, its accumulation in the root mass with subsequent redistribution to the leaves to stimulate the process of photosynthesis is observed.

Твердофазным синтезом при 1200°С получены трикальцийфосфат и Mn,Sr-замещенный трикальцийфосфат (ТКФ). Синтезированные соединения охарактеризованы методами РФА, ИК-спектроскопии, СЭМ. Показано, что в результате твердофазного синтеза ТКФ и Mn,Sr-ТКФ формируются соединения со структурой витлокита. Определены параметры кристаллической решетки и установлен факт внедрения ионов марганца и стронция в структуру ТКФ.

A study is performed of dispersion processes for obtaining selenium colloidal solutions via laser ablation, an ultrasonic bath, an ultrasonic rod vibration system, and mechanical action in order to determine the effectiveness of using colloidal solutions of nanosized selenium. Means are developed for quantitatively determining concentrations of selenium and inorganic components of plant feedstock through inductively coupled plasma atomic-emission spectrometry (ICP–AES) and atomic absorption spectroscopy (AAS). Analytical parameters are obtained for the determination of elements, and the conditions of spectrometer operation are optimized. The chosen means of sample preparation are stepwise microwave heating in a Mars 5 autoclave system. Matrix interference is revealed, and ways of allowing for it are determined. It is established that using ICP–AES and AAS analysis with complementary analytical techniques allows control of the Se content and mineral composition of the feedstock for functional food—matrix elements (Ca, K, Na, Mg, Al, Si, and Fe), concomitant microelements (Ag, B, Ba, Co, Cu, Mn, Mo, Ni, Sr, and Zn), and toxic elements (As, Be, Bi, Cd, Cr, Li, Pb, Sb, Sn, Ti, V, and W)—in a wide range of concentrations—1 × 10−6 to n × 10%—with no matrix separation or use of certified solid reference samples. It is shown that the proposed means of analytical control can be used to create fundamentally new ways of enriching feedstock for functional food with nanosized selenium.

Using atomic-emission analysis with inductively coupled plasma (AES – ICP) and atomic absorption spectroscopy (AAS) were developed methods, which allow rapidly, with good metrological characteristics without prior separation of the matrix and without the use of standard composition samples to determine impurity elements (Ag, Cu, Fe, Zn) of concentrations from 0.0005 to 10 % in medical materials based on calcium phosphate. The relative standard deviation (Sr) is 0.05 – 0.005 at the elements contents from 1 to 10 % and does not exceed 0.15 at the elements contents from 0.0005 to 0.1 %. New analytical control methods have provided research on the development of medical composite materials based on substituted calcium phosphates exhibiting antibacterial activity.

Abstract Determining the presence of impurities, carcinogenic and harmful elements in the synthesized materials is a necessary step to identify the field of application, especially for medicine. Methods have been developed for the atomic emission with inductively coupled plasma (AES-ICP) for simultaneous quantifying of impurities contents: Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Si, Ti, Y, Yb, Hf, V, Zn in new zircon-alumo-ytterbium ceramic materials for medical use. Various schemes for dissolving samples were offered for different types of ceramic compounds. Elements were determinate with founded optimal analytical parameters. The influence and methods elimination of matrix elements (Zr, Al, Yb) were studied. It allowed to determine elements with good metrological characteristics in a wide range of concentration from 1·10-3 to n·10% without preliminary separation of the matrix and without using solid standard samples. The relative standard deviation (Sr) does not exceed 0.12.

It is shown that the molecular composition of the vapor–gas phase of many chemical compounds and their mixtures, including carbides, nitrides, and oxides, is substantially more complex and diverse than it appeared before. In addition to monomeric molecules, various gaseous molecules of these compounds are detected in the vapors of carbides, nitrides, and oxides. Data on the composition of the vapors of nitrides of almost all the chemical elements from the periodic system as well as thermodynamic properties of gaseous nitrides are presented in this work.

Приведены данные по термодинамике испарения вольфраматов щелочных металлов.

Methods of quantitative determination of the platinum content in high-salt solutions have been developed using atomic absorption spectroscopy (AAS). Definitions were carried out for small volume bioassays during the research of functionalization of calcium phosphate substitute materials with anticancer drug, cisplatin. The conditions for the determination of Pt in the flame were optimized. The effects of the cisplatin matrix solutions, salt components and concentrations on the Pt absorption value were found out. The relevance of application of the flame version of the AAS method was shown in order to determine the platinum content in high-salt solutions, over 200 g/l, without matrix separation in a wide range of Pt concentrations from 0.1 to 50 µg/ml. This issue was targeted through the estimation of efficiency of Pt-containing drug incorporation and its dynamics release as an application method in the development of drug delivery systems for bone tumors treatment.