Inorganic Materials (v.54, #14)

The Analytical Control as an Integral Part of Material Diagnostics by Yu. A. Karpov; V. B. Baranovskaya (1363-1370).
Analytical control is an applied subdiscipline of analytical chemistry that involves representative sampling, identification of the chemical (elemental, phase, molecular, isotopic, etc.) composition, metrological characterization of the obtained results, and statement of conformity of the objects under analysis to the imposed requirements. The article provides a description of the above basic components of analytical control alongside important aspects such as unification and standardization and accreditation of analytical laboratories. Special attention is paid to the methodology as the basic component of analytical control, its metrological characteristics, and metrological support of the analysis.
Keywords: analytical control; metrology of chemical analysis; approval of analytical techniques; accreditation

The effect of laser radiation parameters on the sensitivity and relative sensitivity coefficients of element determination in the analysis of various materials by inductively coupled plasma mass spectrometry in combination with laser ablation is studied. It is found that, when the power density of laser radiation is increased above 2 × 1010 W/cm2 for the samples based on silicate glass, basalt glass, and polymetallic sulfides, the laser ablation mechanism changes from thermal to “phase explosion.” It is shown that the coefficients of relative sensitivity of determination of impurity elements with respect to the matrix elements change by no more than 3–5% when the power density varies in the range of 5 × 109–1.5 × 1011 W/cm2. For most impurity elements, the coefficients of the relative sensitivity of determination in different matrices differ by no more than 10–15%, but for a number of elements, a significant difference up to 1.5–2 times is observed. A comparative study of two ablation modes is carried out: when the laser beam is moved along the surface of the sample and during ablation at a “point.” It is shown that the sensitivity of determination of the elements in the first case is 2–3 times higher, while the coefficients of the relative sensitivity of determination are the same for both cases.
Keywords: laser ablation; inductively coupled plasma mass spectrometry

On the Features of Sorption Concentration of Ru on Super-Crosslinked Polystyrenes during the Analysis of Rocks by the Method of Inductively Coupled Plasma Mass Spectrometry by A. S. Dubenskiy; E. D. Yakurnova; I. F. Seregina; L. A. Pavlova; M. P. Tsyurupa; V. A. Davankov; M. A. Bol’shov (1379-1386).
New sorption systems based on a series of super-crosslinked polystyrenes of brands HP and Styrosorb for the concentration of Ru from the solutions obtained after decomposition of rocks are studied. To extract Ru according to a reversed-phase mechanism, aromatic amines (methylbenzylamine (MBA), dimethylbenzylamine (DMBA), dibenzylmethylamine (DBMA)), as well as aliphatic tributylamine (TBA), are used for the first time. It is shown that reverse 60% extraction of Ru from the standardized test solution can be reached in the Styrosorb-514–TBA–1M HCl sorption system in ethanol as a desorption agent. An important role of sample preparation of a solid sample is revealed by the analysis of the reference standards (RSs) of ultrabasic and basic rocks. It is found that, for the quantitative (100%) extraction of Ru in the selected sorption system, the only suitable way of transferring a solid sample to a solution is smelting to NiS matte followed by dissolving of the matte in aqua regia and transferring it to concentrated HCl. The influence of Ni during the mass spectrometric determination of Ru by 99Ru in a broad range of concentrations (20–2000 μg/L) is studied; it is shown that the presence of Ni does not make the Ru concentration too high. The conducted experiments have displayed the possibility for using the sorption system based on Styrosorb-514 when estimating the low content of Ru in rock samples, which is confirmed by the analysis of the reference standards of ultrabasic and basic rocks GPt-5, GPt-6, and SARM-7. The obtained data on Ru content in these objects coincide with the certified values within the confidence interval.
Keywords: ruthenium, sorption concentration, super-crosslinked polystyrene; reversed-phase sorbents, tributylamine, ultrabasic rocks, smelting to NiS matte, inductively coupled plasma mass spectrometry

Use of Piezoelectric Sensors for the Determination of Oleic and Palmitic Acids in Vegetable Oils by O. V. Duvanova; I. A. Krivonosova; A. N. Zyablov; A. V. Falaleev; V. F. Selemenev; S. A. Sokolova (1387-1391).
Piezoelectric sensors based on molecularly imprinted polymers (MIPs) for sensing oleic (MIP-Oleic) and palmitic (MIP-Palmitic) acids were tested in the analysis of vegetable oils. When creating the MIP sensors, electrodes were modified with the PM polyimide (dianhydride of 1,2,4,5-benzenetetracarboxylic acid and 4,4′-diaminodiphenyl oxide). Values of the imprinting factor and selectivity coefficients of the molecularly imprinted polymers for sensing fatty acids were compared. Chromatography mass spectrometry was used as a comparison method. The difference between the results of the determination of acids by using a piezoelectric sensor and by chromatography mass spectrometry does not exceed 10%. It is established that sensors modified with molecularly imprinted polymers are selective to the acid that served as a template for the polymer synthesis.
Keywords: molecularly imprinted polymers; oleic acid; palmitic acid; polyimide PM; piezoelectric sensor; vegetable oils

In this paper, we developed a methodology for the determination of Al2O3, SiO2, CaO, and Fe2O3 in siliceous refractories by using inductively coupled plasma atomic emission spectroscopy (ICP-AES) with microwave sample preparation in an autoclave. We proposed the composition of the acid mixture and the stepwise microwave heating regime that ensure the completeness of sample dissolution and exclude the decompression of the autoclave leading to the loss of analytes in the form of volatile compounds. Cd was anticipated to be used as an internal standard. Calibrated dependences for the determination of normalized macro- and microelements in terms of oxides by ICP-AES were obtained using the method of three standards. The correctness of the developed methodology was confirmed by the analysis of state standard samples and comparison with the results of the Al2O3, SiO2, CaO, and Fe2O3 determination in accordance with GOST. The developed technique makes it possible to reduce both the time required for the analysis by 11 times and the consumption of concentrated acids by 8 times.
Keywords: siliceous (dinas) refractories; microwave sample preparation; inductively coupled plasma atomic emission spectrometry

Contemporary Methods of Detecting Heavy Metals in Waste Waters (Review) by O. A. Dal’nova; G. I. Bebeshko; V. V. Es’kina; V. B. Baranovskaya; Yu. A. Karpov (1397-1406).
The necessity of monitoring the quality of waste waters and their specific features require the presence, development, and improvement of an instrumental analytic base, as well as the implementation of methods of detecting pollutants, including heavy metals. This review article characterizes methods of elemental atomic absorption, optical emission, and mass-spectral ecoanalytical monitoring of waste waters, which are of greatest practical interest. Particular attention is paid to methods using operations on separating and concentrating trace heavy metals.
Keywords: waste waters; sorption; separation; concentration; extraction; toxic elements; metals; atomic absorption spectrometry; optical emission spectrometry; mass spectrometry

Voltammetric Determination of Betulin in the Extracts of Plant Origin by S. S. Kaliyeva; G. B. Slepchenko; Yu. A. Akeneev; Ye. E. Nurpeiis; A. K. Tashenov; E. A. Mamaeva; A. A. Bakibaev (1407-1411).
The electrochemical activity of betulin (the ability to undergo electrochemical oxidation) in aqueous solutions is determined by voltammetry on carbon-containing (glassy-carbon) electrodes. The suggested identification method is based on measuring the values of currents corresponding to the oxidation peaks of active functional groups of betulin, their heights being linearly dependent on the betulin concentration within a range of 1 × 10–6–8 × 10–5 mol/L. The developed voltammetric procedure makes it possible to determine betulin in plant extracts. Voltammetric curves for dry betulin extracts prepared using different purification procedures are obtained to demonstrate the possibility of betulin determination. The results are confirmed in spiking tests.
Keywords: betulin; voltammetry; glassy-carbon electrode; oxidation; methodology

Electron Probe X-Ray Spectral Analysis of Nanoparticles by S. A. Darznek; V. B. Mityukhlyaev; P. A. Todua; M. N. Filippov (1412-1416).
Two approaches for improving the resolution via electron probe X-ray spectral microanalysis (EPXRSMA) are considered for the characterization of the nanoparticle composition. The first approach implies the use of L and M series as the analytical ultrasoft X-ray lines of the characteristic radiation of elements to be detected, which are excited by the low-energy electrons (less than 5 keV). The quantitative EPXRSMA, involving a new way for calculating the matrix element correction, is elaborated for this approach. The extrapolation route for the construction of the calibration characteristic is extended to all elements with Z > 40. The second approach is based on the use of the analytical signal caused by only the excitation by electrons of the probe. The achieved lateral resolution is about 2 nm, and the depth resolution is 20–60 nm. The minimal determined mass of the substance is approximately (1–2.5) × 10–21 g, which corresponds to 10–30 atoms of the detected elements.
Keywords: electron probe X-ray spectral microanalysis (EPXRSMA); resolution; detection limit; nanoparticles

Electron Probe X-Ray Analysis of Nanofilms at Off-Normal Incidence of the Electron Beam by S. A. Darznek; V. B. Mityukhlyaev; P. A. Todua; M. N. Filippov (1417-1420).
The frontier of the electron probe X-ray spectral method in the determination of trace metal quantities on a silicon substrate is studied. The experimental data are acquired for ultrathin chromium films on a silicon substrate. It is shown that the signal-to-noise ratio significantly increases at a noticeable sample inclination (80°), which allows one to determine an extremely low (available by this approach) chromium content. The calibration curve for the inclined sample position is plotted using the Monte Carlo method. The surface concentration of chromium atoms (2.2 ± 0.4) × 1014 cm–2 and the chromium detection limit (5 × 1013 cm–2) are measured under the given experimental conditions. For the electron probe X-ray microanalysis of bulk samples, it is a record value. The equivalent weight of chromium at the aforementioned surface concentration is approximately 4 × 10–18 g. The proposed technique requires no changes in the design of the device to be applied.
Keywords: electron probe X-ray analysis; nanofilms; detection limit; chromium; silicon substrate

Current State and Problems of Analytical Control of Spent Automobile Catalysts (Review) by T. Yu. Alekseeva; Yu. A. Karpov; O. A. Dal’nova; V. V. Es’kina; V. B. Baranovskaya; L. D. Gorbatova (1421-1429).
Abstract—Spent Automobile Catalysts (SACs) hold a special place among secondary raw materials containing precious metals. Accurate determination of platinum group metals in SACs plays an important role influencing the economic efficiency of the utilization process. In this work, we review the methods of analysis of SACs available in the literature, as well as methodological developments of the Giredmet Institute in collaboration with Anserteko and NUST “MISiS”. The main emphasis is placed on the use of modern tools for chemical preparation of hard-to-break objects like SACs, including autoclave and microwave opening of the samples. The advantages of the assay concentration method based on developments at the Yekaterinburg Non-Ferrous Metals Processing Plant for analysis of SACs are considered. We discuss certified spectroscopic and chemical methods which have been developed for analysis of spent automobile catalysts and outline the ways of their further improvement.
Keywords: analytical control; spent automobile catalysts; platinum group metals

ICP-AES Analysis of Secondary Tungsten-Containing Raw Materials for Production of Hard Alloys by A. V. Vyacheslavov; V. B. Bichaev; A. D. Titova; D. S. Rybin; T. N. Ermolaeva (1430-1434).
A method for ICP-AES determination of Ti, V, Cr, Fe, Co, Ni, Cu, Zn, and Ta in recycled cemented tungsten carbide is developed including preliminary microwave sample decomposition in a steam pressure vessel (autoclave). We have specified the composition of the reaction mixture for sample dissolution and optimized the parameters of microwave heating in the autoclave. Correctness of the results is proved by the method of sample weight variation and spike tests. The results of analysis are compared with the data obtained by standardless method of X-ray fluorescence spectrometry. The technique is characterized by good reproducibility and allows significant reduction of the analysis time owing to the combination of the multielement method of ICP-AES and microwave sample preparation.
Keywords: secondary tungsten-containing raw; recycle cemented tungsten carbides; cemented tungsten carbide; microwave sample preparation; ICP-AES (inductively coupled plasma atomic emission spectrometry)

Application of Statistical Methods for Classification of Varietal and Regional Origin of White Wines by V. O. Titarenko; A. A. Khalafyan; Z. A. Temerdashev; A. A. Kaunova; E. A. Ivanovets (1435-1442).
White wines of four wine-growing regions of Krasnodar region were studied by the ICP-AES method. Nineteen elements were identified in 153 samples of white wines of the Chardonnay, Riesling, and Muscat brands. Methods of statistical analysis demonstrated that, despite the complicated technological cycle of wine production (soil–grapes–juice–wine), information about the grape variety and the region of its origin is preserved in the totality of trace elements. Probabilistic statistical models were constructed to identify the grape variety and the region where it was grown by the concentrations of a certain set of microelements contained in wine. The proposed models are based on the assumption that the soil origin is an important factor determining the microelement composition in wine.
Keywords: identification of regional and varietal origin of white wines; content of trace elements in wines; methods of classification trees; discriminant analysis

New Spectral Complexes Based on MAES Analyzers by V. A. Labusov; V. G. Garanin; I. A. Zarubin (1443-1448).
A review of spectral complexes produced by the company VMK-Optoelektronika for atomic emission spectral analysis is presented: Grand-Globula, Grand-Kristall, and Ekspress for the direct atomic emission spectral analysis of solid metal and powder samples; Grand-Potok for the express analysis of powders by a spill–injection technique; Grand-Ekspert and Favorit for the express analysis of metals and alloys; a facility for spark sampling Aspekt for the analysis of metal samples with the help of ICP-AES and ICP-MS; Ekspress-Oil for the direct analysis of oils; and Pavlin for the express determination of sodium, lithium, potassium, calcium, barium, cesium, and rubidium in solutions. The composition and technical characteristics of the spectrometers are reported.
Keywords: atomic emission spectral analysis; spectral complexes; spectrometers; spectrum analyzers; multielement solid-state detectors; linear arrays of detectors; spectrum excitation sources

In the article, a method and tools for the automatic estimation of the content of chemical elements using a single spectrum of a sample are described. The presence of the elements in the sample is determined by the technique of cross-correlation qualitative analysis, featuring a low probability of false detection and high speed. The content of the detected elements is calculated using the method of emergence and strengthening of spectral lines modified for the use in an automatic mode in modern spectral complexes. The tools need tuning to a certain complex with the help of the results of quantitative spectral analysis obtained using this complex earlier. The tool operating efficiency is demonstrated with the estimation of the content of the elements of the basis of geological powder samples (Si, Ti, Al, Mg, Fe, Ca, Mn) using the spectra obtained with two different spectral complexes.
Keywords: cross-correlation function; qualitative analysis; estimation of the content; atomic emission spectra; multielement solid-state detectors

Optical Efficiency and Spectral Resolution of the Grand, Grand-1500, and STE-1 Spectrometers by A. A. Dzyuba; V. A. Labusov; I. E. Vasil’eva; E. V. Shabanova (1456-1460).
For comparing the characteristics of the Grand, Grand-1500, and STE-1 spectrometers, which are used as a part of a scintillation atomic emission complex in a combination with an electric arc setup Potok for analysis of powdered samples by the spillage-injection method, their optical efficiency, reciprocal linear dispersion, and spectral resolution are measured in the 235–344 nm region. The spectral resolution of the Grand-1500 spectrometer is 1.5–2 times better than that of the other studied spectrometers. The resolution of the Grand and STE-1 spectrometers in the fifth diffraction order is practically the same, whereas in the fourth order the resolution of the Grand is significantly better. In the 240–270 nm region, the optical efficiency of the Grand exceeds that of the STE-1 by an order of magnitude, and by a factor of 4 in the 342 nm range. The optical efficiency of the Grand-1500 near 240 nm is slightly higher than of the STE-1, whereas at 267 and 342 nm it exceeds it by a factor of 2 and 5, respectively.
Keywords: MAES; spectrometer; arc atomic emission spectrometry; spectral resolution; optical efficiency

Capabilities of a Two-Jet Arc Plasma for Direct Analysis of Samples of Different Nature by N. P. Zaksas; A. F. Veryaskin; V. A. Labusov (1461-1464).
The capabilities of a two-jet arc plasma for solving analytical tasks that are difficult to do by other spectral methods have been shown. We have proposed procedures, both direct and after heat treatment of the sample, for the atomic emission spectroscopic analysis of brown coal and protein complexes of low weight using graphite-powder-based reference samples and simple sample preparation (dilution of the sample with spectroscopic buffer). Owing to the ability of the ATOM program to record the spectra of each base exposure, a method for detecting inclusion elements in diamond particles weighing less than 1 mg has been proposed. The advantages of this method over other spectral methods in solving specific analytical tasks are discussed. All the techniques described in the work have been performed using a new design plasmatron developed by VMK-Optoelektronika.
Keywords: two-jet plasma; brown coal; protein; diamond; inclusion elements

A fast multichannel analyzer of emission spectra (MAES) for the Grand spectrometer with a combined hybrid assembly of 12 BLPP-369M1 arrays (for the 190–350 nm spectral range) and one BLPP-2000 array (for the 258–269 nm spectral range) has been created. The minimum exposition time of the analyzer is 3 ms. It is shown that, at the base exposition time of 3 ms, the signal-to-noise ratio for the flashes of the analytical Au 267.595 nm line is a factor of 10 higher when recorded using the BLPP-2000 array as compared to the BLPP-369M1 array.
Keywords: time-resolved spectroscopy; atomic emission analysis; powdered geological sample; scintillation; solid-state light detector; lowering the detection limit of element