The quality of chemical analysis is inextricably linked with such concepts as the methodology of analysis, unification, certification and standardization. In essence, a modern analysis technique is a type of software that allows quality control of the specific types of substances and materials in chemical composition. The methodology is a formalized regulatory document implemented at different levels — in the form of a certified procedure, in the form of an enterprise standard method, in the form of a unified industrial method, in the form of a national (state) and international standard. It is through the use of analysis techniques provides consumers, product manufacturers, and scientists with the most important information about the composition of a huge variety of substances and materials, the reliability of which allows their specific use and determines the cost of production. Therefore, the development and application of the methods need legal regulation both at the national and international levels. Features of standardization of analytical methods are considered in the case study of the quality control of metallurgical products.

The main sources of spectral interferences in atomic emission spectral analysis (AESA) are considered, including both wide-range (bremsstrahlung and recombination continuum, radiation of hot condensed particles and electrode ends, scattered light in the spectrometer, overlapping of the analytical line by the wings of the neighbor strong spectral lines of interfering elements, imposition of the components of molecular bands with the very close lines) and narrow-band (partial or complete overlapping of the analytical line with atomic or ionic lines of the sample elements, electrodes and discharge atmosphere; superposition of spectra from higher orders of reflection in conventional diffraction spectrometers and from neighboring orders in two-dimensional echelle spectrometers). The features of their manifestation in various sources of spectrum excitation (flames, DC arc, spark discharges, arc plasma discharges, inductively coupled plasma, microwave plasma, low-pressure electric discharges, laser spark) are considered. The possibilities of reducing the level of spectral interferences or elimination of the spectral noise at the stage of design and manufacturing of AESA devices, as well as upon selecting and adjusting of operation conditions of the analysis are shown. Much attention is paid to the most easily implemented in practice off-peak correction of wide-range spectral interferences. The modern methods of background correction under the spectral peak (under-peak) using a software for atomic emission spectrometers and providing creation of various mathematical models of the background signal in the vicinity of the analytical line at the stage of developing a specific AESA technique are considered. The issues of the choice of spectral lines for analytical measurements, tables and atlases of spectral lines, electronic databases used for this purpose are considered in detail. Specific features of application of the method of inter-element correction with direct spectral overlapping of the lines are given. The operating sequence for taking into account spectral interferences when developing the analysis techniques is proposed.

A system of the set rules, procedures and regulatory documents is developed in the Central Analytical Laboratory of the JSC «EZ OCM» for the method of atomic emission spectral analysis of precious metals with arc excitation of the spectrum to meet all the requirements of the accrediting body «Rosakkreditatsiya». The features of managing the measuring instruments — spectrometers with MAÉS analyzers, auxiliary equipment and microclimate are considered. The requirements to the personnel of the laboratory for spectral analysis are considered. The rules for developing measurement procedures, instructions for laboratory technicians, measuring programs, methods for performing routine analysis of the samples, and ensuring the traceability of measurement results are specified. The availability of using «ATOM3.3» software for solving everyday problems of the laboratory is shown.

The concentrations of the impurities in brown coals some of Kazakhstan deposits — «Kulan», «Shoptikol’», «Oi Karogai», «Sarykum» — were determined. Surface inclusions in coals were studied using optical USB microscopes. The composition of inclusions and total composition of coals were analyzed by both X-ray spectrometry with energy dispersion and atomic emission spectrometry using «Grand-Potok» complex with sample introduction by the spill-injection method into an arc discharge and recording spectra with an analyzer MAÉS. Gold was determined on a «Grand-Potok» complex using scintillation method. The coals of «Oi Karogai», «Sarykum», and «Kulan» deposits exhibited inclusions of pyrite in crystalline form. It was shown, that both gold and silver are present only in the coals of the «Shoptikol’» deposit in the form of flat round inclusions. Inclusions formed particles of gold-silver alloy upon melting according to data of scintillation analysis. The average concentrations of gold and silver in the coal samples of the «Shoptikol’» deposit are 0.007 and 0.03 ppm, respectively. It is shown that scintillation determination of precious metals in brown coals of Kazakhstan on a «Grand-Potok» complex with MAÉS analyzer is more rapid compared to the methods of inductively-coupled plasma-mass spectrometry (ICP-MS), atomic emission spectrometry (AES) and atomic absorption spectrometry (AAS) at comparable detection limits.

An additional photodetector array BLPP-369 was installed on a «Grand-Potok» complex for rapid atomic-emission determination of the fluorine concentration in fluorite samples. Introduction of fluorite samples was carried out using the spill-injection method simultaneously with high pure calcium oxide introduction using the second conveyor belt. The use of an additional photodetector array with a spectral range of 528 – 536 nm provides the possibility of expanding the spectrum of CaF molecular lines with the intensity sufficient for determination of fluorine concentrations in fluorite samples. A calibration curve for fluorine determination in a concentration range of 0.12 – 47.63% was plotted using measurement results for 200 fluorite samples. Integration of the additional photodetector array provided increased detection limit for the mass fractions of fluorine up to the maximum possible concentrations in fluorite samples. The observed effect simplifies and speeds up the analysis in the absence of the necessity to dilute the sample, thus reducing the error of measurements. The results show that there is no need to introduce additional buffer mixtures (except CaO) and use reference lines to determine the fluorine concentration, which also simplifies the measurement procedure.

A method for trace element concentration in the microwave accelerated reaction system MARS 5 is developed. The vapor-phase distillation was used to remove high-purity germanium dioxide matrix as volatile germanium tetrachloride (GeCl₄). We specified operating conditions of the microwave system and chose a halogenating agent and its volume. The method of quantitative chemical analysis of germanium dioxide by direct current arc atomic emission spectrometry (DCA AES) was developed. The unit for analysis is equipped with a multichannel spectrum analyzer MAÉS produced by «VMK-Optoélektronika». We also determined the residual content of germanium in the resulting solutions after vapor-phase distillation. The limits for detection of 46 trace elements in DCA AES analysis of germanium dioxide with preconcentration of trace elements ranged from 0.5 ng/g to 1 μg/g. We carried out validation of the combined procedure using «spike test».

An arc atomic emission technique of hafnium determination in zirconium is developed and tested. The study was carried out on a PGS-2 spectrometer equipped with MAÉS analyzer and information processing software «Atom 3.3». («VMK-Optoélektronika», Novosibirsk). Excitation of spectra of pre-oxidized metal was carried out using a medium-frequency generator «Vesuvius» («VMK-Optoélektronika», Novosibirsk). Analytical line of hafnium was free of spectral overlap with the lines of zirconium. We have set a current of the AC arc discharge (20 A), exposure time (30 sec) and the form of the electrode into which the sample is placed («narrow crater») are selected. The effect of buffering additives (graphite powder, bismuth fluoride) on the intensity of the analyte lines was studied. It is shown that high sensitivity of the analyte is observed for oxidized material without additives. Reduction of the random error attributed to the influence of conditions of spectrum excitation and sample preparation is achieved using the intensity ratio of the analyte line and zirconium as an analytical signal. Recommendations regarding preparation of the samples for calibration are given. The lower limit of the determined concentration is 0.01% with a relative standard deviation in repeatability 3%.

Study of macro- and microelement composition of the ash of plant raw materials revealed the prevailing matrix elements, their chemical form and content. It is shown that direct determination of the impurities in mineral residues by the method of arc atomic emission spectroscopy with a multichannel analyzer of emission spectra (MAÉS) is complicated by the impact of the macro component and its chemical form on the intensity of the spectral lines of the impurities. Introduction of a corrective additive is proved to eliminate this effect. A technique for measuring the mass fraction of macro elements and trace elements in plant ash is proposed and metrological certification of the procedure is carried out.

Features of determination of trace elements in saliva samples by atomic emission spectrometry with excitation of the spectrum of the sample dry residue from the end of the carbon electrode in AC arc discharge are studied. The samples were analyzed directly after sampling, additional manipulations (including digestion) were not performed. The spectra of dried residues of the samples were recorded on a spectral device MFS-8, modernized with a MAÉS photodiode array. It was found that experimental distributions of P and Ca contents in saliva samples obey the normal law. Concentrations of Mg, Si, Fe, Ti, Mn, Al, Cu, Zn, and Cr correspond to the log-normal distribution and the geometric mean value should be used in this case as an average value of the concentration. Statistical processing of the results for Cd, Ag, and Pb was not performed, since these elements could not be detected in all the samples. The obtained data on the content of elements in 60 saliva samples of various donors are in satisfactory agreement with the literature data. The overestimated results obtained for Mg, Ca, and P can be attributed to the difference in the sample preparation stage, including preliminary centrifugation and storage of samples at negative temperatures.

150 years ago D. I. Mendeleev revealed the Periodic law to the world and since that time periodic dependencies have been increasingly used in various fields of basic and applied sciences. For the first time we consider the regularities of periodic dependences of the concentration of chemical elements in the ash residue of human hair on the number of the element. Such dependencies for various regions of Russia reveal strictly individual character. It is shown that distributions of the chemical elements for men and women also differ, as well as the distributions determined for the same groups in inhabitants of different regions of residence and depend to a significant extent on the genetic and physiological characteristics of human organism, variability of environmental conditions, earlier diseases and other impacts. This means that population of different urban regions (e.g., Siberian region) is characterized by a strictly individual distribution of biogenic elements. A hypothesis has been put forward that extrema observed on the studied dependences can be a kind of code for a given locality, reflecting correlation with various factors of genetic and ecological nature.

The goal of the study is the choice of algorithms for optimization of arc atomic emission spectral analysis with MAÉS to elaborate the techniques of quantitative spectral analysis of different objects. The choice of the algorithms is performed on an example of geologic objects with alumosilicate matrix. Determination of the elemental composition of such geological objects is important for obtaining markers, studying geochronological processes, and searching for mineral deposits.

It has been shown that «Grand» spectrometers based on a hybrid assembly of BLPP-2000 photodetector arrays produced by «VMK-Optoélektronika» can be used for atomic emission spectral analysis of solutions using inductively coupled plasma atomic emission spectroscopy (ICP-AES). For the prototype of a «Grand-ICP» spectrometer consisting of «Grand» spectrometer, microwave plasma generator, and RF (radiofrequency) generator, the following analytical characteristics were determined: element detection limit, long-term stability, linear ranges of calibration graphs for several elements, and optimal operating parameters of the microwave generator. The linear concentration range of analyte elements is 10⁵ when using a single analytical line of the element. The long-term stability is less than 2% in 6 h without using an internal standard. The detection limits are comparable to those of modern ICP spectrometers with an axial plasma survey and lie in a range of sub-microgram per liter. It has been found that the effect of superposition of the spectral lines of the plasma background, for example, OH molecular lines or others, on the analyte lines can be eliminated by subtracting the blank sample spectrum from the analyte spectrum using Atom software. The analytical characteristics of the spectrometer allow the use of the device both for developing new ICP- based systems and restoring the performance of defective ICP spectrometers.

Modernization of «Grand-Potok» atomic emission complex with MAÉS analyzer («VMK-Optoélektronika», Novosibirsk, Russia) first designed for analysis of powder samples is considered in view of the possibility of analysis of solutions and aqueous aerosols avoiding changes in the sample injection. It is shown that upgraded input system equipped with a nebulizer provides determination of platinum and gold in aqueous solutions with detection limits 1 – 5 ppm. Analysis of water aerosols with silver nanoparticles by scintillation method revealed the possibility of detecting separate silver nanoparticles about 200 nm and more. Thus we have demonstrated that modernization of the complex provides the possibility for analysis of solutions and aerosols obtained upon electro-spark and laser ablation of various materials, as well as for microanalysis of the objects.

It is known that the working properties of motor oil are determined by the presence of some elements of the periodic table. The properties of oil can vary significantly over time due to exposure to both high and extremely low pressures and temperatures. To ensure uninterrupted long-term operation of equipment, it is necessary to monitor various indicators of oil, including the determination of wear metals on a regular basis. Two methods of determining wear metals are most widely used: an electric arc with a rotating graphite disk and inductively coupled plasma. The goal of the work was to determine wear metals in oil using a microwave nitrogen plasma source and an «Ékspress» spectrometer according to ASTM D5185-09 method. Microwave plasma was produced using an industrial magnetron with a frequency of 2.5 GHz and a microwave resonator which provided toroidal plasma shape. Nitrogen (purity of 99.6%) was used as a plasma-forming gas. In accordance with the mentioned procedure, a series of wear metal samples was prepared by adding metal oxides to the base oil for comparison with the control experiment. After that, the solutions were diluted 1:10 by weight with kerosene to eliminate the difference in viscosity of the samples and ensure their spraying using a pneumatic spray. The spectrometer allows simultaneous recording of spectra in the region of 190 – 360 and 390 – 540 nm with an integration time of 70 msec. The intensity of C₂ and CN molecular bands was reduced by introducing air into the intermediate flame of the burner. The constructed calibration graphs for determination of Al, Pb, Fe, Cu, Cr, Cn were used in analysis of the control sample. It is shown that wear metals in oil can be determined using microwave plasma as a source of spectrum excitation.

The main directions in the development of the spectral systems for scintillation atomic emission analysis of powdered geological samples are aimed at increase in the sensitivity, spectral resolution, and speed of the spectrum analyzers to reduce the detection limits. The goal of the study is developing of high-speed MAÉS analyzers with hybrid assemblies of the arrays of 14 multichannel photodetectors of two types: high-sensitivity BLPP-2000 and BLPP-4000 photodetector array with high spatial resolution and theoretical estimation of the signal-to-noise ratio when recording scintillation and integral spectra with aforementioned photodetectors. The high-speed MAÉS analyzers with BLPP-2000 and BLPP-4000 photodetector arrays are designed so as to provide parallel readout of photodetectors in hybrid assemblies. They consist of 14 BLPP 2000 or BLPP 4000 photodetectors and records the spectra in the 190 – 350 nm wavelength range on a «Grand» spectrometer. The minimum exposure time is 0.9 and 1.7 msec, respectively. It is shown that in measurements of spectral-line intensities using BLPP-2000, the signal-to-noise ratio is 3 times higher in integral analysis and 5 times higher in scintillation analysis compared to measurements with BLPP-4000 photodetector array.

«Atom» software is used in integrated spectral devices for atomic emission and atomic absorption analysis produced by «VMK-Optoélektronika». Development of the new spectral instruments and upgrading of existing devices, birth of new mathematical methods and algorithms for processing spectral information, as well as user stories motivate and promote improvement of the software. This paper presents the main developments and most noticeable changes in «Atom «software for the period 2017 – 2018. The developed 64-bit version of «Atom» software removed the limitation on the amount of recorded sequences of spectra and significantly speeded up their processing by parallelizing the calculations on the processor cores (rather important step, for example, in scintillation atomic emission spectrometry). To implement continuum source electrothermal atomic absorption spectrometry for simultaneous multi-element analysis, we have developed the «Automatic Dispenser» and «Absorption Spectrometer» tools and have implemented the method proposed by D.A. Katskov to linearize calibration dependences in a wide range of concentrations. The possibility of spectrophotometric determination of substances in the solutions of their mixtures has been also implemented. The «Barcode Scanner» and the «Automatic Start of Measurement» tools have been developed to speed up and automate the analysis procedure. The software is supplemented with a set of useful functions designed for further development of analytical methods and programs of analysis.

The width of a spectral line in atomic emission spectral analysis with arc radiation sources is, as a rule, much smaller than the hardware function of the spectral device. Thus, the spectral line shape is determined by the hardware function of the spectral device and can be approximated, for example, by the Voigt function. However, when analyzing standard samples with a wide range of element concentrations, the problem of self-absorption often occurs, due to which the analytical line has to be changed, which is not always possible. We propose to modify the Voigt function by adding a factor that describes self-absorption, by analogy with the Bouguer-Lambert law. The possibility of using the proposed function was evaluated in analysis of standard samples of rocks, ores and sandstones on a Grand-Potok spectral system with a MAÉS analyzer and BLPP-2000 linear photodetector arrays. The use of proposed approximating function is shown to provide an increase in the working range of the calibration curves of Cu 327.3954 nm, Cu 324.7532 nm, Pb 287.3311 nm, Ni 305.0818 nm, and Mo 313.2594 nm by 1 – 3 orders of magnitude.

Modern small-sized spectrometers are designed mainly by Czerny – Turner scheme with a flat diffraction grating, and with the goal of the maximum aperture at the expense of resolution — by the scheme with a concave diffraction grating with a flat field. Spectrum registration in such spectrometers is carried out by linear photodiode array. The aim of the work is to inform professionals about the characteristics of the compact spectrometers developed by the authors. These spectrometers use unpackaged linear photodiode arrays for spectrum registration that eliminate the reflection of radiation from the cover glass of the photodiode array and reduce stray-light. The tightness of the spectrometer housing increases their service life. The modification parameters of the spectrometer designed according to Czerny – Turner scheme are given. The main advantage of the spectrometer is the low stray-light inside the device and the same spectral resolution throughout the spectral range. The working aperture in Czerny – Turner scheme is limited by aberrations to 1/6. The scheme with a flat field allows operation with a larger working aperture. Three modifications of the spectrometer are developed according to this scheme (description of their main parameters is given). The results of experimental comparison of the spectrometers with different optical schemes in the light intensity and spectral resolution are presented, along with the examples of their application. Devices designed according to Czerny – Turner scheme are used in atomic emission, atomic absorption spectral analysis, and in spectrophotometry for registration of absorption spectra of condensed media. Luminescence and Raman spectra of minerals are recorded on a flat-field spectrometer. The developed compact spectrometers have an operating spectral range 190 – 1100 nm with the possibility of registering spectral regions from 70 to 1000 nm, the best resolution being 0.1 nm and the stray-light level less than 0.05% with the minimum recorded optical density of more than 3. Flat field spectrometers have an increased aperture due to the large working aperture 1/2.1.

The operation speed of commercially available spectral-ratio pyrometers and brightness pyrometers often appears insufficient for control of fast-changing temperature (e.g., in a graphite cell of an AES electrothermal atomizer, the rate temperature change is 10⁴ °C/sec). An advantage of spectral pyrometers is high speed and ability to measure the temperature of objects with unknown emissivity. The goal of this study is to develop a high-speed spectral pyrometer based on a «Kolibri-2» spectrometer with BLPP-2000 photodetector array that provides a wide working wavelength range 400 – 1050 nm, and minimum basic exposure time of 0.4 msec. The temperature was calculated by plotting the emission spectrum of the object in Wien coordinates (with allowance for calibration of the spectral pyrometer using radiation source of the known temperature) and measuring slope of the obtained graph. The relative error of temperature measurements on a spectral pyrometer estimated by comparing measurement results and data obtained with a calibrated Termokont-TN5S1M (Termokont company) single-channel pyrometer was not more than 1.5% in a temperature range of 1000 — 2400°C and higher, and rapidity up to 2500 measurements/sec. The results of measuring temperature of the graphite cell of the electrothermal atomizer using a spectral pyrometer during sample atomization at a rate of temperature change up to 10 000°C/sec are presented.

Features of training specialists, bachelors, and masters in the field of atomic emission spectral analysis at the Department of Physical and Chemical Methods of Analysis [Ural Federal University (UrFU)] are considered. When training bachelors, coverage of the specialty course «Methods of atomic spectral analysis» is reduced almost by half compared to the same course for specialist. Length of practicals and research trainings is also significantly reduced. Therefore, students graduated with a bachelor degree can be incorporated into the actual practical activities of the laboratories at the enterprises and research companies only in laboratory positions. Master’s program is deeper in theoretical knowledge and research training and practicals become of particular importance. Thus, only a full cycle of two-level education can be comparable with the previous engineering training of specialists. The structure of the curriculum and features of setting up advanced training courses (additional professional education) for specialists in analytical laboratories focused in particular on a detailed study of the features of recording atomic emission spectra by the MAÉS analyzer using the ATOM program is presented. The experience of advanced training of the personnel of industrial laboratories conducted at the training centers of UrFU is described. This form of additional professional education is recommended for advanced and refresher’s training of the laboratory personnel at large enterprises.

This publication gives brief information about the system of reference materials (RM) in the Russian Federation, particularly in the field of legal and regulatory support for the production and use of RM. The role of the State service for reference materials of composition and properties of substances and materials is discussed along with the components of state regulation in view of formation of the national market of reference materials. The aspects of «search» for RM that are necessary for implementation of the measurement tasks assigned to the laboratory are shown. The information about large producers of RM in metallurgy, nuclear energy and geology is presented.

A study of the repeatability and long-term stability of elemental content measurements in a UG20 standard sample using a vacuum atomic emission spectrometer «Grand-Expert» was carried out on time scales of 10 min and 1 h. The values of standard and expanded uncertainty of the results of carbon, chromium, manganese, nickel and silicon determination which characterize the repeatability and long-term stability of measurements were calculated. It has been shown that a vacuum atomic emission spectrometer «Grand-Expert» provides determination of the content of alloying elements in steel with a relative expanded uncertainty of 1 – 2% whereas measurements of carbon content are characterized by higher relative expanded uncertainty of about 3%.

A two-jet plasma is used for direct atomic emission analysis of powdered samples. It is characterized by relatively weak matrix effects, which allows using unified calibration samples on the basis of graphite powder for analysis of the samples with inorganic, organic, and organomineral matrix. In the present paper the effects limiting the usage of the unified approach due to different thermal stability and evaporation efficiency of the samples are discussed. The understated concentrations of a set of elements (Al, Ba, Ca, La, Mg, Mn, Sr, Ti, and Y) were obtained in analysis of certified reference materials of geological samples. It was shown that determination of rare earth elements should be carried out in the region behind the jet confluence providing their complete evaporation. For other elements, registration of the spectra in this region improves the results to some extent but they do not achieve the certified values. To speed up evaporation of these elements, the experimental conditions were chosen for plasma chemical reactions which provide conversion of the matrix elements into more volatile compounds. Addition of ammonium hydrofluoride to powdered sample considerably increased the line intensities of Al and Ca strongly associated with the silicon matrix. Incomplete evaporation was observed in analysis of biological samples with particle size more than 100 μm. A decrease in consumption of carrier argon is quite enough for effective decomposition of the organic matrix in plasma; the value of gas consumption depends on thermal stability and particle size of the sample. Preliminary sample carbonization is another way to improve evaporation of biological samples.

The degree and nature of the violation of local thermodynamic equilibrium (LTE) in the analytical zone of a plasma jet generated by an argon arc two-jet plasmatron (TJP) was estimated using an unconventional method based on determination of the nonequilibrium parameter b_i equal to the ratio of the experimentally determined actual population of the energy level (n_i) of the element to the population of the same level calculated from the Saha equation (n_is). Partial ionizing deviation of plasma under study from the equilibrium state takes place only when low-lying atomic levels are overpopulated. The distinct dependence of b_i on the ionization potential of the considered element (e.g., Ca, Mg, and Be) is shown. The results were interpreted in the light of the increasing role of radiation processes upon excitation of spectra in the argon arc two-jet plasmatron.