Inorganic Materials (v.46, #14)

Determination of platinum and palladium in dead catalysts using inductively coupled plasma atomic emission spectrometry after sample digestion by high-temperature fusion by T. M. Malyutina; T. Yu. Alekseeva; A. V. D’yachkova; G. S. Kudryavtseva; L. D. Berliner; Yu. A. Karpov (1479-1482).
A technique for the determination of platinum and palladium in dead catalysts using ICP-AES after sample digestion by high-temperature fusion with potassium pyrosulfate is described. The technique is universal; it offers the possibility to analyze various brands of catalysts and their mixtures at a content of platinum and palladium of 0.1% to whole units of percent in a short time. The accuracy of results of determination of platinum and palladium is confirmed by comparison with the data of interlaboratory control. The relative standard deviation in the developed technique is 4–2.5% for the content of platinum and palladium of 0.1 to 0.5% and 2–1% for higher concentrations of these elements.

Determination of impurities in high-purity germanium dioxide using atomic emission spectrometry by T. A. Chanysheva; I. R. Shelpakova; A. I. Saprykin (1483-1486).
A technique for the determination of the impurity composition of soluble germanium dioxide and one containing up to 0.1% insoluble in 12 M HCl is described. The technique offers the possibility to control the content of 31 impurities simultaneously after preconcentration with detection limits of about 10−6 to 10−8 wt % and with an intralaboratory precision not exceeding 20 rel. %.

Laser-induced breakdown method for code detection (identification) in explosion products of coded explosives by Yu. K. Karasevich; A. Yu. Kulagin; A. M. Skripkin; P. A. Khatyushin; Yu. A. Karpov (1487-1492).
The results of a study on the development of a method for coding explosives are presented. As coding additives (CAs), it is proposed to use aluminum alloy powders with dosed amounts of rare-earth coding elements (CEs). This choice is dictated by the fact that aluminum alloys are commonly used as efficient additives in explosive compositions, while rare-earth elements are used as additives in technological operations, but are absent in the composition of standard explosives. In this case, the key to information on a given explosive and its manufacturer is the ratio of CE concentrations determined when analyzing explosives, e.g., when investigating an act of terrorism. Examples of explosion product decoding using a LIES laser-spark express analyzer.

Catalytic kinetic methods for determining osmium (review) by D. B. Petrenko; O. A. Tyutyunnik; Yu. M. Dedkov (1493-1498).
Catalytic kinetic methods for determining osmium are reviewed. It is shown that almost all indicator reactions used for catalytic kinetic determination of osmium are redox ones. As oxidizers, Ce (IV) ion, bromate, periodate, and iodate ions, and hydrogen peroxide are used, as a rule. As reducers, organic dyes are used in most cases; inorganic reducers, mainly arsenous acid and its salts, are used slightly less often. It is found that the pyrogallolphthalein oxidation reaction in the presence of polyoxyethylene glycol dodecyl ether is characterized by the best sensitivity for determining Os (VIII) (the detection limit is 5 × 10−5 ng/cm3). Techniques based on the reactions of As (III) oxidation by bromate, iodate, and periodate ions and N-methyl-n-aminophenol oxidation by hydrogen peroxide are very sensitive and selective. The most promising ways to improve the catalytic kinetic techniques for determining osmium are found.

Atomic absorption determination of mercury in solid samples of placer gold by N. V. Ivannikova; O. A. Shiryaeva; Yu. A. Karpov (1499-1502).
The possibility of atomic absorption determination of mercury in solid samples of placer gold is shown. Mercury-gold compounds with a variable composition are assumed to be found in the process of thermal atomization. The conditions that contribute to an increase in the degree of atomization of mercury in the process of heating of a solid sample in the range of concentrations above 10−7 wt % are selected.

Techniques of selection from several variants of the optimal method of sample preparation with the use of modifications of clustered ranking are considered. Algorithms of construction and improvement of rational schemes of sample preparation and atomic-absorption analysis to solve series of geochemical problems are suggested. Application of rational schemes of analysis constructed as individual blocks of methodical techniques decreases the economic cost for analysis and achieves an increase of reliability of the obtained results.

Analysis of silicate materials using the microwave-assisted sample preparation by N. V. Korsakova; E. S. Toropchenova; L. V. Krigman; N. V. Budarina; I. V. Kubrakova (1513-1517).
A technique of microwave-assisted preparation of natural and commercial silicate materials for subsequent spectrophotometric determination of the major rock-forming components (silicon, aluminum, iron, titanium, and phosphorus) is described. The total duration of analysis is several times less than for a standard technique. In particular, the time taken for the digestion is shortened to 1 h for ten samples undergoing digestion simultaneously; the time of complexation of aluminum with aluminon and of phosphorus with molybdenum heteropoly acid is reduced from a few hours to 12 min.

The results of applying heterogeneous chemiluminescent analysis for determination of micro-components are generalized, and the possibility of using this method for determination of toxic anions in waters is demonstrated. Anions undergo conversion beforehand, which causes formation of new analytical forms, i.e., derivates being active in chemiluminescent reactions with luminol. If volatile products are generated as analytical forms, they undergo gas extraction from the matrix with detection using a chemiluminescent indicator in the carrier gas stream at the interface gas-liquid (aqueous solution of luminol). Thus, the techniques for determination of Cl, Br, I, ClO 3 , BrO 3 , IO 3 , NO 3 , NO 2 , S2, CrO 4 2− , AsO 2 , Cl2 and chloramines are developed. The detection limit (DL) is 0.5–5.0 μg/l, and the analysis time is 2–9 min. In another case, products of conversion are sorbed from the solution on a solid sorbent, and detection is carried out by a luminol solution on the solid surface. A series of heteropoly acids (phosphorus, arsenic, silicon, and germanium) and their ion associates with cation surfactants, along with other large anions, are determined in the form of sorbable ion associates. The DL is 0.02–0.7 μg/l, and the analysis time is 30 min. The advantages of application of heterogeneous chemiluminescent analysis over analysis in homogeneous media are indicated, and the prospects for development of the theoretical bases and field of application are demonstrated.

X-ray diffraction determination of the composition of In x Ga1 − x Sb solid solution by Yu. N. Parkhomenko; A. A. Shlenskii; V. F. Pavlov; G. V. Shepekina; T. G. Yugova (1526-1528).
A procedure to determine the composition of In x Ga1 − x Sb solid solution by X-ray diffraction is described. In order to calculate the indium content in a solid solution, an expression is proposed which relates the cell size of an undeformed layer with the dimensions of a tetragonally distorted unit cell of the layer under strain caused by a discrepancy in the dimensions of the layer and substrate lattices. The procedure yields results that well agree with measurements of the solid solution composition in a layer by energy dispersive spectroscopic control performed using an electron microscope.

Computer diagnostics of the mesoscopic structure of nanoporous aluminas by N. M. Yakovleva; A. N. Yakovlev; M. M. Gafiyatullin; A. I. Denisov (1529-1535).
A method based on the computer analysis of electron microscopic images of the surface of porous anodic aluminas is described for deriving quantitative information about the mutual arrangement of cells and pores (mesoscopic structure). The developed package of programs is used to calculate dimensional parameters of a cellular-porous structure, the size distribution of the image objects, and the morphological functions of the radial distribution of cells/pores, which are analogs of the function of the radial distribution of atoms characterizing the short- and medium-range orders of atoms in amorphous materials. A quantitative analysis is performed for the first time using the method of pair functions, which was used earlier for identification of the atomic structure in amorphous films. The developed package of Spot Calculator and MFRD programs for processing electron microscopic images of the surface can be used to study the mesoscopic structure of not only porous aluminas but also any materials if characteristic features can be distinguished on their surface.

Grain-size analysis of silicon powder by A. E. Stolina; N. V. Pimenova (1536-1540).
The results of the silicon powder grain-size composition found with the use of an optical microscope, Analysette-22 NanoTec laser diffraction microanalyzer, and SF-2 scanning photosedimentometer are presented. Choosing the dispersion conditions, in particular, the properties of a dispersive liquid and the ultrasonic generator power, is of great importance in setting a powder sample for analysis. Comparing three analytical procedures, one may note that the laser diffraction method offers a number of advantages over the other two; a wide measurement range, considerable number of processible particles, and short analysis time are among the advantages. Obtaining an undistorted image of an object under investigation is an advantage of optical microscopy.

Control over the substructure of single-crystal blades of gas-turbine engines by F. A. Sidokhin; A. F. Sidokhin; E. F. Sidokhin (1541-1542).
The methods of “rocking curves” used for industrial control and investigation of single-crystal articles is shown to be unable to provide reliable data. The reason is attributed to the fact that the employed conditions of obtaining “rocking curves” are unsuitable for solving this problem and, as a result, the instrumental half-width of the peaks turns out to be too large and uncontrollable since it depends on the size of the subgrains that are the object of the investigation.

Measurement of specific surface and porosity of catalysts by R. M. Khafizova; I. A. Borisova (1543-1544).
The specific surface of solids is necessary to analyze surface processes involving molecules or atoms (adsorption, catalysis, and others). In these cases, it is very important to have data not only on the geometrical surface of a solid but also on its actual surface for particular molecules. The difference between these surfaces for coarse-grained systems can be neglected; however, it can be significant for fine-grained and microporous materials.

It is shown that the positron annihilation spectroscopy (PAS) method is one of the most effective ways of determining the sizes of nanoobjects (vacancies, vacancy clusters, free pore spaces, cavities, and voids) and their concentrations in the place of annihilation of positrons in porous systems and in a wide range of technically important materials and nanomaterials. The possibilities of the method are demonstrated by example of porous silicon and silicon irradiated with protons.

Wavelet processing of nanocomposite images obtained by scanning tunnel and electron microscopes by V. A. Tkal’; N. A. Voronin; V. G. Solov’ev; N. O. Alekseeva; S. V. Pan’kova; M. V. Yanikov (1555-1557).
The technique of digital processing of images obtained using a nanotechnological complex on the basis of a Umka-02-E scanning tunnel microscope and Philips XL30 scanning electron microscope is described. It is capable of efficient elimination of factors complicating the analysis, such as weak contrast ratio and background nonuniformity of images. Experimental images of nanocomposite material opal-InSb, which includes nanoparticles of indium antimonide in the porous dielectric matrix of opal, underwent wavelet processing. In addition to enhanced quality of the analyzed images, the technique makes it possible to reduce the aliasing effect (discrete structure of the image being reconstructed) in wavelet processing.

Fracture toughness and hydrogen embrittlement of pipes with notches by Zh. Kapel’; Yu. G. Matvienko; G. Pluvinage (1558-1563).
A technique for experimental determination of fracture toughness and hydrogen embrittlement of pipes made of API 5L X52 steel is described. The tests were performed using arc-shaped specimens with a notch cut out from pipes under the conditions of a three-point bend. The fracture toughness was determined in terms of the J-integral and the stress intensity factor at the notch tip. The value of K ρ,c was established using the volumetric method based on the experimentally measured critical load and the results of the FEM calculation of the distribution of elastic-plastic stresses ahead of the notch tip, and J ρ,c was determined using the method of separable functions. The effect of hydrogen embrittlement was studied using electrolytically prehydrogenated specimens.

A method is described for estimating the ultimate state of structural materials in terms of variations of microhardness. The method includes investigations of the effect of low temperatures on the strength of cracked specimens made of grade 16G2SAF steel, as well as tests on low-cyclic fatigue of specimens made of grade 15 steel. After cyclic stressing, the specimens are exposed to uniaxial extension up to destruction, and then the microhardness is measured on the specimen fracture. Then the ultimate curve of elasticity losses is plotted, from which the coefficient of elasticity loss is determined. The curve of microhardness as a function of coefficient of elasticity loss is used for estimation of the ultimate state of a material.

Prediction of damage under multicycle loading by V. L. Kolmogorov; B. G. Burdukovskii; I. S. Kamantsev (1567-1569).
The processes of damage accumulation and failure in a strained metal under multicycle fatigue are described. Fatigue failure is regarded as a process of gradual accumulation of scattered microdefects in each material particle of a strained piece under cyclic loading. In terms of the phenomenological theory of damage accumulation, a technique for calculating the damage is described.

High-cycle fatigue failure of low-carbon steel after long-term aging by L. R. Botvina; I. M. Petrova; I. V. Gadolina; V. P. Levin; Yu. A. Demina; A. P. Soldatenkov; M. P. T’utin (1570-1577).
The characteristics of nucleation and development of fatigue cracks under high-cycle loading of plane samples of low-carbon steel are studied after its natural aging for 15 years. Cumulative distributions of the number of microcracks with respect to their length are constructed and the fracture microrelief is studied. It is found that the fatigue strength of the steel decreases considerably in the high-cycle region (>107 cycles) at a stress less than the fatigue strength.

The specific character of requirements for standard and reference samples in electron probe X-ray microanalysis (EPMA) defined by locality of the method is considered. It is noted that availability of standard samples for all necessary and possible determinations using EPMA is a rather acute problem. Possible ways of examining the suitability of substances for the use in EPMA as reference and standard samples are described.

Problems of providing traceability of measurements obtained using physicochemical measurement instruments during their production and operation are discussed in the article. The main condition of provision of traceability is the presence of a standard, calibration procedure, and calibration instruments, the role of which standard samples play for physicochemical measurement instruments, as a rule. Results of analysis of the state of measurement traceability during production and operation of physicochemical measurement instruments, performed according to data of descriptions of the types of measurement instruments included in the State Register of Measurement Instruments, are presented.

The article discusses the features of analytical control of secondary raw materials containing precious metals. The classification of such material is developed. The procedures of sampling and analysis in the certification of secondary precious metals are described. Special attention is paid to the certification regulations at the Shchelkovo Factory of Secondary Precious Metals, control of analytical accuracy, and application of statistical data in estimation of the raw material quality. It is mentioned that the analytical division of the Shchelkovo Factory of Secondary Precious Metals is a certified entity and provides sufficient quality of analytical control.