Inorganic Materials (v.53, #14)

Detection of Sodium in Highly Pure Graphite via High-Resolution Electrothermal Atomic Absorption Spectrometry with a Continuous Spectrum Source by V. V. Es’kina; O. A. Dal’nova; L. Kh. Tursunov; V. B. Baranovskaya; Yu. A. Karpov (1379-1381).
This study is dedicated to elucidating the analytical abilities of electrothermal atomic absorption spectrometry with a continuous spectrum source (ETAAS-CSS) to detect the presence of sodium in highly pure graphite powder. In order to plot the calibration dependence for sodium detection, a special technique based on argon dilution of the atomic vapor obtained by introducing the aqueous reference solution in the atomizer is applied. The conditions for thermal pretreatment of highly pure graphite powder and atomization of sodium are established, and the sodium detection threshold is evaluated via ETAAS-CSS (2.6 × 10–4 ng) as well. The validity of the results is confirmed via the sample variation method.
Keywords: sodium; detection; electrothermal atomic absorption spectrometry with a continuous spectrum source; highly pure graphite

Time-Efficient LC/MS/MS Determination of Low Concentrations of Methylphosphonic Acid by T. M. Baygildiev; I. A. Rodin; A. N. Stavrianidi; A. V. Braun; D. I. Akhmerova; O. A. Shpigun; I. V. Rybal’chenko (1382-1385).
A time-efficient protocol for quantification of methylphosphonic acid (MPA), a final hydrolysis product of nerve agents in aqueous environments, via liquid chromatography mass spectrometry is described. Chromatographic separation and mass spectrometry detection conditions are optimized to enable high sensitivity, selectivity, and accuracy of the approach and to eliminate impeding matrix effects associated with the analysis of water samples of natural origin. The developed technique is tested by analyzing the samples of natural waters that are spiked with a known quantity of MPA. With direct LC/MS/MS, the detection limit for MPA in natural waters is 10 ng/mL.
Keywords: nerve agent degradation products; methylphosphonic acid; LC/MS/MS; water analysis

It is shown that the employment of a quartz capillary column with carbon adsorbent provides an effective separation of impurities of permanent gases, carbon dioxide, nitrous oxide, C1–C2 hydrocarbons, and carbon dioxide in monogermane. The effect of the injected volume of monogermane specimen on the determination of ethane and carbon dioxide is studied. Chromatography mass spectrometry detection limits of impurities are (1–10) × 10–6 mol %. The detection limit of the limiting impurity represented by ethane is decreased by the factor of seven as compared to the published data.
Keywords: high-purity monogermane; adsorption capillary column; impurities; detection limit; accuracy; chromatography mass spectrometry

Advanced Techniques for Sample Processing of the Reusable Metal-Containing Raw Material (Review) by M. S. Doronina; Yu. A. Karpov; V. B. Baranovskaya (1391-1398).
A review of the sample processing of different types of reusable metal-containing material (catalytic agents, e-wastes, cuttings, etc.) is given in the article; the purpose of the sample processing is the further analysis in the form of solutions: dilution in the mineral acid mix, alloying with different fluxes, leaching, etc. Increase in the temperature and pressure, ultrasonic impact, and microwave radiation are applied for the purpose of sample processing intensification. Methods of sample processing with application of sorbate concentration for the further definition of not only the noble, nonferrous, and rare metals but also the toxic elements are described. The review shows that the stage of sample processing is very important for achieving the potential of the applied analytical methods.
Keywords: reusable metal-containing raw material; sample processing; noble metals; toxic elements; sorbate concentration

Determination of the Mode of Occurrence of V, Fe, and Mn in Slags and Charge of Vanadium Production by X-Ray Spectroscopy by P. A. Zhdanov; I. F. Seregina; K. B. Osipov; M. A. Bol’shov; E. A. Skryleva; A. I. Volkov; A. N. Seregin (1399-1404).
Samples of technogenic raw materials are studied by spectroscopic methods. The chemical composition of a roast slag and a charge of vanadium production is analyzed by the X-ray fluorescence method (XRF). The possibilities of X-ray photoelectron spectroscopy are studied for determination of the oxidation state of elements in technogenic raw materials. It is found that ~30% of V occurs in the slag as V(III), whereas, in the charge, the content of V(V) and V(IV) is ~80 and 20%, respectively; no V compounds with the lowest oxidation states are found. Iron in the slag and charge samples is present as Fe3O4, and Mn mostly occurs as Mn(III). The oxidation state of V in the slag and charge can be determined by the intensity ratio of the K and L lines of the XRF spectra; however, this method is not recommended because of its low accuracy.
Keywords: vanadium slag; vanadium charge; element shapes; X-ray fluorescence analysis; X-ray photoelectron spectroscopy

Determination of Main Components of Glass-Forming Cu–Zr Alloys by N. V. Pechishcheva; O. V. Evdokimova; A. V. Maiorova; K. Yu. Shunyaev (1405-1410).
A rapid procedure is developed for determination of copper and zirconium in their binary alloys Cu100–x Zr x in the content ranges corresponding to the region of bulk amorphization (x = 30–70) using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The spectrometer operating conditions are optimized, and the analytical spectral lines (Cu II 224.700 nm and Zr II 354.262 nm) are selected, as well as calibration method and sampling procedure: dissolution in the mixture of HNO3 and HF with addition of HCl, providing for the minimum standard deviation of the analytical signal. A procedure of oxygen determination by inert gas fusion technique and a procedure for determination of copper by spectrophotometry and zirconium by gravimetric analysis in a single sample together with quality control of ICP-AES are developed for the considered alloys. The results of analysis of Cu100–x Zr x alloys according to the developed procedures agree well between themselves and accounting for adjustment of oxygen content agree within the error limits (not more than 0.5 wt %) with the added content of copper and zirconium upon synthesis.
Keywords: copper–zirconium alloys; chemical analysis; inductively coupled plasma atomic emission spectroscopy; gravimetric analysis; spectrophotometry; inert gas fusion technique

Combined Methods of Analysis of Metal-Containing Raw Material (Review) by M. S. Doronina; Yu. A. Karpov; V. B. Baranovskaya (1411-1417).
Methods of analysis of reusable metal-containing material (RMR) are considered in the review: X-ray fluorescence, atomic absorption spectrophotometry, and atomic emission and mass spectrometry with inductively coupled plasma. Peculiarities of the applied methods are shown, and a method of analysis with consideration of the specificity of RMR should be developed for every object. In the most cases, the methods of sample processing harmonized with the applied method of analysis and sample content.
Keywords: metal-containing raw material; X-ray fluorescence; atomic absorption spectrophotometry; ICP-MS; ICP-AES; platinum group metals; determination

A procedure for decomposing samples and determining rhodium in environmental objects by the catalytic method according to the reaction of sulfarsazen oxidation with periodate is proposed. The accuracy of the results is confirmed by determining rhodium using the method of inductively coupled plasma mass spectrometry. It is established that the rhodium content in the samples of road dust in Moscow is 0.01–0.04 g/t depending on the place of sampling. The standard deviation of repetition of the results of rhodium determination does not exceed 0.05.
Keywords: rhodium; kinetic catalytic method of analysis; urban environment

Application of Microwave Plasma Atomic Emission Spectrometry and Hydride Generation for Determination of Arsenic and Selenium in Mineral Water by I. V. Mikheev; E. A. Karpukhina; L. O. Usol’tseva; T. O. Samarina; D. S. Volkov; M. A. Proskurnin (1422-1426).
The ability to determine arsenic and selenium at their maximum acceptable concentrations (MAC) in drinking water via microwave plasma atomic emission spectrometry (MP-AES) and hydride generation is shown in this study. The determination of these elements is possible even in samples with a high degree of mineralization (up to 12 g/L). To provide the required sensitivity of determination of both elements, certain operating modes of the spray chamber for hydride generation are chosen. The conditions for the determination of these elements in mineral and medical-table waters are proposed.
Keywords: microwave plasma atomic emission spectrometry; generation of hydride species of elements; mineral water; selenium; arsenic; determination

Voltammetric Determination of Carmoisine in Soft Drinks by O. I. Lipskikh; E. I. Korotkova; E. V. Dorozhko; K. V. Derina; O. A. Voronova (1427-1431).
A voltammetric study of the electrochemical behavior of red food azo dye Carmoisine on a glassy carbon electrode (GCE) is performed. The influence of various factors on the cathode signal of the dye is shown: pH and values of accumulation time and potential sweep rate. The operating conditions of Carmoisine identification in model media are selected: pH = 1.65, E acc = –0.1 V, t acc = 10 s, W = 100 mV/s. A linear dependence of the electrolytic reduction current of the dye on its concentration at –0.15 V is observed within 0.05–0.5 mg/L; detection limit of Carmoisine is 0.02 mg/L. A comparative determination of Carmoisine in soft drinks is performed by voltammetric and spectrophotometric methods.
Keywords: azo dyes; Carmoisine; voltammetry; spectrophotometry; soft drinks

Stable Highly Enriched Isotopes in Routine Analysis of Rocks, Soils, Grounds, and Sediments by ICP-MS by V. K. Karandashev; V. A. Khvostikov; S. V. Nosenko; Zh. P. Burmii (1432-1441).
Two procedures of acid digestion in an open system and in autoclaves are developed for routine ICP-AES and ICP-MS analysis of rocks, soils, grounds, and sediments. Proposed is a technique based on the use of stable highly enriched isotopes produced in Russia which enables the control (although with certain limitations) over the digestion procedure for each analyzed sample.
Keywords: isotope dilution; mass spectrometry with inductively coupled plasma; autoclave digestion; rocks; grounds; soils; bottom sediments

Specific Features of Application of Different Methods of Analytical Control of Spent Catalysts of the Petrochemical Industry by L. D. Gorbatova; Yu. N. Godovykh; A. A. Shtukina; G. R. Iskhakova; Yu. A. Karpov (1442-1447).
A method of analysis of samples of spent petrochemical catalysts based on acidic decomposition of samples with further determination of platinum by inductively coupled plasma mass spectrometry is developed. The method allows analyzing various brands of catalysts, mixtures, and waste of catalysts formed during regeneration. A comparative study of the results of platinum determination obtained by different analytical methods in samples of several types of catalysts is performed. It is shown that spectrophotometric method of platinum determination in spent alumo-platinum catalysts recommended for certification of batches of catalysts and umpire analysis is not universal. At comparable accuracy indices, the analytical method should be selected taking into account the specific features of a particular batch of catalysts and restrictions of the applied method.
Keywords: spent alumo-platinum catalysts; precious metals; analytical control; restrictions in application of analytical methods; spectrophotometry; inductively coupled plasma mass spectrometry; accuracy indices

Determination of Microelements in Oil by Combined Sample Preparation Technique by E. Yu. Savonina; T. A. Maryutina; O. N. Katasonova (1448-1453).
The determination of a wide spectrum of microelements in four oil samples from the Arlanskoye, Labaganskoye, Priobskoye, and Romashkinskoye oil fields of the Russian Federation by inductively coupled plasma mass spectrometry (ICP-MS) is described. The following two techniques have been used for the sample preparation: microwave decomposition of oil for determination of Be, Na, Mg, Al, S, Ca, Ti, V, Cr, Co, Ni, Cu, Zn, Ga, Se, Rb, Sr, Zr, Mo, Cs, Ba, W, Re, and U; and extraction concentrating with rotating helix columns (RHC) for determination of Nb, Ru, Rh, Ag, Cd, Sb, Te, Hf, Ir, Pt, Te, and rare earth elements. Concentrating of the oil microelements with RHC has been shown to result in significant improvement of the ICP-MS detection limits.
Keywords: extraction; microwave decomposition; sample preparation; rare earth elements; oil; inductively coupled plasma mass spectrometry

Analysis of the Samples with an Unknown Matrix Using Data Mining Algorithms by E. I. Molchanova; E. N. Korzhova; T. V. Stepanova; V. V. Kuz’min (1454-1457).
In determining a limited number of analytes in samples having a complex chemical composition with an unknown matrix, the combination of data mining algorithms (problems of clustering and regression) is proposed. This makes it possible to compensate for the influence of the components of the host medium on the intensity of the analytical line of an element being determined. The technology developed is tested in the X-ray fluorescence determination of S, Fe, Cu, Zn, and As in float concentrate samples during processing of polymetallic ores and V and Fe in synthetic film samples that are adequate in physicochemical properties to samples of welding fumes deposited on a filter. The error of the results of analysis has decreased by a factor 1.5–5 compared to the use of the Lucas-Tooth classical regression equation. The developed technology considerably increases the rapidity of analysis when it is used with X-ray spectrometers of consecutive action.
Keywords: data mining algorithms; cluster; heterogeneous materials; X-ray fluorescence analysis; models of calibration functions; regression equations; least-squares method; calibration samples; adequacy error

Synthesis of ZnO Thin Films Doped with Ga and In: Determination of Their Composition through X-Ray Spectroscopy and Inductively Coupled Plasma Mass Spectrometry by D. G. Filatova; N. A. Vorobyeva; M. N. Rumyantseva; V. B. Baranovskaya; A. E. Baranchikov; V. K. Ivanov; A. M. Gaskov (1458-1462).
An approach is proposed to study the composition of synthesized thin zinc films doped with In and Ga through local X-ray spectral analysis (LXSA) and inductively coupled plasma mass spectrometry (ICP-MS). A relationship between the amount/distribution of additives in the sample and synthesis conditions on rotating substrates is found. The results of determining the dominant impurities in film solutions with ICP-MS are used to validate those obtained with the LXSA method without sample preparation. To find doping impurities at an amount less than 1 at % is possible only through the ICP-MS method.
Keywords: new materials; thin films; inductively coupled plasma mass spectrometry; X-ray spectroscopy; zinc; gallium; indium

Evaluation of the Component of Bias of X-Ray Microanalysis Related to Surface Relief of the Specimen by A. L. Vasil’ev; V. B. Mityukhlyaev; A. A. Mikhutkin; P. A. Todua; M. N. Filippov (1463-1466).
A semiempirical approach to the a priori evaluation of the effect of the surface relief on the results of X-ray spectral analysis of binary compounds is proposed. Dimensionless parameter k characterizing the effect of the relief on the intensity of intrinsic X-ray radiation is determined using the experimental data obtained for reference monocrystal specimens GaAs with known geometrical parameters of the relief.
Keywords: X-ray microanalysis; surface relief; bias