Emission Spectroscopy Method Research Articles

DETERMINATION OF ECOTOXIC SUBSTANCES IN WASTEWATER FORMED IN THE PURIFICATION PROCESS OF PETROLEUM OILS WITH HYDROGEN BY SPECTRAL METHODS

The article analyzes the determination of the amount of dissolved ecotoxicants in the sample taken from the industrial wastewater obtained during the process of hydrogen treatment of petroleum oils. During the hydrogenation process, different types of wastes are formed, depending on the nature of each compound contained in petroleum distillates. Every gas, liquid, solid waste formed during the process of hydrogen purification of petroleum distillates by the oil refining industry has a negative impact on the environment in various ways. One of the main directions of our scientific research is the ecological assessment of the environmental impact of wastewater formed in the process of hydrogen treatment of petroleum distillates.Based on the results obtained, the environmental impact of the wastewater was assessed. The amount of volatile ecotoxicants in the wastewater sample was determined by spectral methods and is shown in the table. We used gas chromatography-mass spectrometry method for the polycyclic aromatic hydrocarbons; optical emission spectrometry method for metals; spectrometry method for phenols, dyes and fluorine; nephelometry method for turbidity; the gravimetry method for total suspended particles. Based on the results obtained, it is possible to assess the environmental impact of wastewater generated during the technological process at the hydrogen treatment plant. According to the results of the research, it can be noted that the industrial wastewater discharged from the oil refinery's facility № 501 has a content that will damage the ecosphere and biosphere, despite the fact that the discharge standards meet the permissible discharge limits

NO BIOMARKER: TRANSMISSION AND EMISSION METHODS FOR ITS POTENTIAL DETECTION IN EXOPLANET ATMOSPHERES WITH SPEKTR-UF (WSO-UV)

Among all habitability factors for terrestrial exoplanets, one of the most important is the presence of a secondary N2–O2 dominant atmosphere in an exoplanet. This factor can potentially indicate the already existing geological and biological processes on the exoplanet. Meanwhile, direct characterization of the N2–O2 atmospheres of terrestrial exoplanets is a difficult observational task. There are only a few indicators (molecules) of such an atmosphere, among which one can single out a potential biomarker – a molecule of nitric oxide NO. The strongest spectral features of this molecule in the ultraviolet range are γ-bands (203–248 nm). An important role in the search for potential biomarkers on exoplanets, including the registration of NO γ‑bands, can be played by planned for the launch WSO-UV space observatory. In the paper estimates of the possibility of detecting the transmission of light in γ-bands in the atmospheres of exoplanets with this observatory are presented. The methods of emission and transmission spectroscopy are compared as applied to the detection of NO. Based on the results of this work, it is shown that there is a potential possibility of detecting a transmission signal in the NO γ-bands in the atmospheres of nearby exoplanets (10 pc) using the LSS spectrograph of the WSO-UV observatory. At the same time, the imposed restrictions for the registration of this signal on more distant exoplanets are presented.

STUDYING THE CHEMICAL COMPOSITION OF WASTE WATER FOR THE PRODUCTION OF GLYCORRICE ROOT AND GLAUCONITE FROM KARAKALPAKIA

In the article, the amount of micro-and macro-elements in two types of glauconite produced during the industrial processing of licorice root from Beruni district of Karakalpakstan was studied based on the inductively coupled coil optical emission spectrometry method and compared with those in the literature. The obtained results were used to study the amount of macroelements K and R necessary for plants in the composition of soil and glauconite, and it was shown that it is possible to produce new types of organomineral fertilizers based on them. It has been shown that the processing of licorice root in our republic can solve the problems of disposal of industrial waste.Based on the obtained results, the scientific basis of organomineral fertilizer production was developed based on the studied glauconite and wastewater and licorice root industrial waste.

RISK QUOTIENT OF ZINC (Zn) AND CHROMIUM (Cr) LEVEL IN DUG WELL WATER IN THE COMMUNITY LIVING AROUND LANDFILL SITE

ABSTRACT Background: Zinc and chromium are heavy metals that can contaminate community-dug well water that is used by people around landfills, and can cause public health problems. This study aimed to analyze the risk level of zinc (Zn) and chromium (Cr) content in the dug well water of the community around Sukawinatan landfill site. Methods: This research was an observational study using a cross-sectional design with an environmental health risk analysis approach, It was conducted in February–May 2021. The sample was water from the dug wells of the community that lives around the Sukawinatan landfill. The examination of zinc and chromium level in dug well water was used the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) method. Results: Zinc and chromium level in community dug well water was found to range from 0.03 mg/l to 0.09 mg/l for zinc concentration and from 0.0030 mg/l to 0.04 mg/l for chromium concentration, respectively. The results of calculating the potential dose (intake) for the two metals are still below the dose reference value, and for calculating the level of risk, the result is less than 1, which can be interpreted as not being risky. Conclusion: Zinc and chromium level in the community's dug-well water around the landfill site was still below the quality standard. The potential dose (intake) and Risk Quotient were safe for the next few years.

Promoting densification and grain growth of BaCe0.65Zr0.2Y0.15O3-δ

BaCe0.65Zr0.2Y0.15O3-δ (BCZ20Y15) has raised great interest due to its good protonic conductivity and chemical stability. However, the sintering of the material is considerably challenged by its refractory nature. In the current work, almost fully densified single-phase BCZ20Y15 with grain sizes exceeding 10 μm was successfully fabricated by sintering at 1500 °C by using calcined powders consisting of naturally separated perovskite phases and 0.5 wt% NiO. The role of NiO as sintering aid was elucidated by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Atom Probe Tomography (APT) methods, concerning global and local material composition. Furthermore, the mechanism leading to the promoted densification and grain growth is elucidated based on current experimental results and a comprehensive review of the literature.

Interaction of Cold Atmospheric Pressure Plasma with Soybean Seeds: Effect on Germination and DNA, Seed Surface Characteristics and Plasma Diagnostics

This study investigates the relation between cold atmospheric pressure plasma (CAPP) effect on seeds and the plasma parameters. As a source of CAPP, the diffuse coplanar surface barrier discharge (DCSBD) generated in nitrogen, ambient air, and oxygen at atmospheric pressure was used. Results of germination and the level of DNA damage of soybean seeds (Glycine max L.) treated in plasma and plasma gaseous products showed that the most advantageous is the use of ambient air plasma treatment. The water contact angle (WCA) of samples treated directly in plasma was significantly smaller than that of samples treated with gaseous products. Using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), we did not observe significant changes between the spectra of individual samples, what indicates that there is no damage on the surface of the samples during the treatment, only the binding of polar groups. The method of optical emission spectroscopy (OES) and Fourier transform infrared spectroscopy (FTIR) were used to study the plasma parameters. The most radiant system observed in ambient air and nitrogen plasma is the second positive system of nitrogen N2C3∏u→B3∏g\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{N}}_{2} \\left( {{\ ext{C}}^{3} \\prod _{{\ ext{u}}} \ o {\ ext{B}}^{3} \\prod _{{\ ext{g}}} } \\right)$$\\end{document}. FTIR measurements showed the presence of reactive oxygen and nitrogen species O3, NO2, N2O, NO, HNO2 depending on the working gas. Finally, it can be assumed that the positive effect of plasma on the seed is caused not only by the individual components of the plasma, but also by their synergistic effect, while the ratio of the individual active particles as well as the plasma exposure to the seeds are important.

Highly selective adsorbents based on silica gel chemically modified with sulfur-containing groups of arched structure for preconcentration and determination of palladium(II) in products of processing of sulfide copper-nickel ore

Adsorbents based on silica gel chemically modified with arch structure 2-aminophenyl disulfide (DSS) and bis[3-(triethoxysilyl)propyl]tetrasulfide (TSS) groups have been synthesized. The proposed adsorbents quantitatively extracted (extraction ∼99 %) only palladium(II) among all platinum metals from solutions of 2 M HCl - pH 4. Quantitative extraction of Pd(II) was not interfered with 106-fold excesses of alkaline, alkaline-earth, 104-fold excesses of non-ferrous metals and iron, 102-103-fold excesses of other platinum metals. Pd(II) was eluted quantitatively (desorption ∼99 %) from the adsorbents surface with 5–10 % thiourea solutions and could be determined in the eluate by inductively coupled plasma optical emission spectrometry (ICP-OES). The adsorption capacity of DSS and TSS adsorbents was not changed after 5 adsorption-elution cycles. The limit of detection of palladium in the analyzed solution, calculated using the 3 s-criterion, was 0.1 μg/L for solid-phase extraction-inductively coupled plasma optical emission spectrometry (SPE-ICP-OES) method with a preconcentration factor of 50. Intensive yellow-orange color of the palladium surface complex was used in the development of express test-methods for its determination. SPE-ICP-OES and test methods were used in the determination of palladium in certified reference materials of sulfide copper-nickel ore and products of its technological processing.

The Identity and Mineral Composition of Natural, Plant-Derived and Artificial Sweeteners.

The qualitative X-ray phase analysis of natural and artificial food sweeteners was applied to trace the authenticity of such food additives. The mineral composition of different sweeteners commonly added to foods was studied to estimate their mineral profiles and assess the risk related to the toxic elements intake caused by sweetener consumption. The concentration of twenty elements (Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sr, Ti, V, and Zn) was measured using the inductively coupled plasma-optical emission spectroscopy (ICP-OES) method after the representative samples were wet-digested with a concentrated nitric acid and hydrogen peroxide mixture in a closed-vessel microwave-assisted system. Differences between the mineral compositions of the examined sweeteners were statistically evaluated and discussed. The relationships between the concentrations of the elements determined in the analyzed sweeteners were also investigated. The successful application of the X-ray powder diffraction method proved the identity of all investigated sweeteners; all the analyzed products contained the expected sweetening agent. The results of the quantification of all the elements in the examined sweeteners indicated that these products cannot be considered nutritionally dense. Hence, the presence of toxic elements like Cd, Cr, Ni, and Pb distinctly indicates the need to test such products to guarantee their quality and ensure consumer safety.

Selective depolymerization of sugarcane bagasse anaerobic digestate to highly stable phenols-rich bio-oil with the iron-doped K-feldspar catalyst

Sustainable implementation of thermochemical conversion of biomass to targeted products is dependent on innovations in catalyst design and tuning of structure–property relationships. This study details the use of potassium feldspar (K-feldspar) as a support doped with different iron (Fe) concentrations via wet impregnation (WI) method for hydrothermal liquefaction (HTL) of sugarcane bagasse anaerobic digestate. The Fe/K-feldspar supported catalysts were synthesized and characterized using X-ray diffraction, Inductively Coupled Plasma Optical Emission spectroscopy, Brunauer-Emmet-Teller and Scanning Electron Microscopy analytical methods. Amongst all the catalysts, K-feldspar dopped with 10 wt% Fe (WI-10) was more effective, producing 51.2 wt% bio-crude. The catalyst’s activity has been related to the balanced proportion of the microcline: sanidine: haematite (2.8:3.3:1) phases of Fe present on the catalyst, the surface area (porosity), and the surface functionality, thus conferring desirable activity properties. In addition, the WI-10 catalyst had a better selectivity towards substituted phenols that can potentially be used for higher-value applications such as the production of Nylons 6 and 66, and bioplastics. The bio-oil produced with WI-10 has also been demonstrated to be highly stable. The catalyst was reusable up to four times maintaining moderate catalytic performance, and a simple regeneration protocol was shown to restore the activity of the catalyst. The resulting solid residue also exhibited promise as a viable material for use in electrodes for Lithium-ion batteries (LiB). Therefore, this research has demonstrated a promising and sustainable resource recovery strategy for valorising wet biomass wastes into streams of useful products for valuable chemical production and energy application.

An improved analytical method for the quantification of iron, copper and manganese in non-centrifugal sugars (NCS)

Many of the food commodities have dedicated sample preparation, analysis and standard reference methods to determine the multi-element composition using different spectrometry techniques. The composition of elements in non-centrifugal sugars (NCS), like Ca, Fe, Mg, K, and Zn have been reported in the literature by several investigators, however, the analytical protocol is not standardised. NCS serves as a good source of Fe, Cu and Mn sharing considerable percentages of the recommended daily allowance (RDA). The mineral content in NCS varies significantly depending on the feedstock and production process employed. In the present work, we have developed an integrated sample preparation and analytical method for Cu, Fe and Mn in NCS. Response surface methodology (RSM) was employed for the optimization of microwave-assisted digestion. Central composite design (CCD) helped to elucidate the optimum conditions and interactive effects of independent variables like acid volume (12 ml, HNO3), hold time (17.5 min), microwave power (750 W) and sample weight (0.55 g) in the digestion process. Furthermore, the inductively coupled plasma optical emission spectrometry (ICP-OES) method was developed for the quantification of the said trace elements. Analytical curves were drawn for the respective elements and the limits of detection (LOD (mg/kg); 0.006 (Cu), 0.005 (Fe) and 0.005 (Mn)) and limits of quantification (LOQ (mg/kg); 0.020 (Cu), 0.023 (Fe) and Mn (0.016)) were determined. Moreover, the repeatability and reproducibility of the method were examined. The precision and accuracy of the method were found to be well within the recommended limits as per the literature. The proposed method would help to determine the nutritional value of a given NCS sample in a reliable manner.

A xenon collisional-radiative model applicable to electric propulsion devices: III. Determination of the ionization fraction in low-temperature xenon plasma by using ionic and atomic 6p lines

The ionization fraction is a key figure of merit for optimizing the performance of plasma device. This work presents an optical emission spectroscopy (OES) method to determine the ionization fraction in low-temperature xenon plasma. The emission line-ratio of xenon ionic and atomic 6p–6s transitions is used in this method. A comprehensive collisional-radiative model developed in our previous work is employed to describe the relationship between the line-ratios and the plasma parameters. It is found that some special line-ratios have a sensitive relationship to the ionization fraction, e.g. the ratio of the 460.30 nm line and 828.01 nm lines. These line-ratios are selected for the diagnostic method. The method is demonstrated in a magnetized discharge chamber. The axially-resolved emission spectra of the ionization chamber are measured, and from those the ionization fraction along the chamber axis is determined via the OES method. The axially-resolved ionization fraction is found to be dependent on the magnetic field and agrees well with those obtained from a Langmuir probe. In the experiment, the probe is overheated under some conditions, possibly due to the bombardment by energetic particles. In this case, no results can be obtained from the probe, while the OES method can still obtain reasonable results. Combined with optical tomography and spectral imaging technology, the OES method can also provide the spatial distribution of the ionization fraction, which is needed for revealing the discharge mechanisms of plasma devices.

An optical emission spectroscopy method for determining the electron temperature and density in low-temperature xenon plasma by using a collisional-radiative model considering the hyperfine structure of emission line into metastable state

Optical emission spectroscopy (OES) is an important technique for the diagnostics of plasma parameters in the development of plasma devices and material processing technology. OES depends on the collisional-radiative model which can accurately describe the kinetics of excited species in plasma. Metastable species usually have higher density (2–4 orders of magnitude) and longer lifetime (3–6 orders of magnitude) compared to other excited species, thus play important roles in the reaction kinetics. However, the kinetic of metastable species can be complex due to the transport and self-absorption processes, which may lead to coupling of the plasma reaction kinetics in the adjacent areas. Moreover, the line splitting of some elements make the description of metastable kinetics more complex. This work presents an OES method based on a collisional-radiative model considering the hyperfine splitting of emission lines into metastable levels. The density distribution of metastable state is determined by the self-absorption effect. It is then taken into the rate balance equations of other excited species to make an accurate description of metastable related kinetics. The electron density and temperature are determined based on this model. The OES method is demonstrated on a miniaturized electron-cyclotron-resonance ion thruster. The metastable density, electron density and electron temperature are determined along the radial direction of the ion thruster, which can be useful for revealing the physics of discharge phenomenon and optimizing the performance of the plasma source. This method can be used to determine electron parameters in a large pressure range.

Coumarin Based Fluorescent Probe for Detecting Heavy Metal Ions.

Heavy metals such as Iron, Copper, and Zinc are micro-essential trace metal and involve animportant biological role, but it quickly turns toxic at exceeding the permissible limit, causing gastrointestinal irritation, liver, bone, and kidney damage, as well as disorders including Wilson's, Parkinson's, and Alzheimer's. It is important to detect the metal ions as well as their concentration quickly and affordable cost using organic probes. Among the organic probes,the coumarin fluorescent probe shows a very prominent candidate with heavy metal ions. Therefore, in the present review, we reviewed the very recent literature the identify the heavy metals using modified coumarin fluorescent probes. Readers will get information quickly about the method of preparation of modified coumarin core and their use as fluorescent probes with heavy metals using absorption and emission spectroscopic methods along with the probable mechanistic pathway of detection.

An approach for measurement of the magnetic field near the surface of plasma-facing components in tokamak by laser induced breakdown spectroscopy based on Zeeman effect

Laser-induced breakdown spectroscopy (LIBS) has been demonstrated to diagnose the surface element distribution of plasma-facing components (PFCS) in fusion devices. However, the magnetic field intensity and polarity near the wall surface change frequently and cannot be measured in real time, which will affect the analytical accuracy of LIBS results. The determination of the strength and polarity direction of the magnetic field near the surface will be conducive to the quantitative analysis of LIBS and provide valuable information for the distribution of the magnetic field near the surface of PFCs. In this work, the effects of magnetic fields on the characteristics of laser-induced Mo plasma, such as the ablation depth and mass, the spatio-temporal evolution behavior of spectrum and the plasma parameters, were first systematically investigated. The different phenomenon of continuum radiation, Mo I line and Mo II line under the magnetic field were mutually verified by optical emission spectroscopy and fast plasma imaging methods. Meanwhile, an approach for measurement of the magnetic field intensity and polarity near the surface of PFCS by LIBS method has been proposed and investigated. When the magnetic field polarity is changed, the spatial distribution profile of Mo spectrum will drift in the opposite direction affected by of the Lorentz force, which realizes the measurement of magnetic field polarity. Moreover, the splitting distance of Mo I line caused by Zeeman effect with the variable magnetic fields were preliminarily calculated. The experimental values of splitting distance agree well with the theoretical values that calculated by the known magnetic field strength. These results confirm the feasibility of measuring the magnetic field intensity and polarity of PFCs surface by LIBS approach.

Влияние биогумуса на основе отходов птицеводства на физико-химические свойства дерново-подзолистых почв и выращиваемых растений

Introduction. The current phase of mass production in the poultry products sector creates large volumes of waste in the form of chicken manure. This waste contributes to the negative environmental impact on the neighboring territories. To address the issue of storing chicken manure, several methods have been developed, of which incomplete combustion and composting with gradual decay are two major ones. The application of both technologies results in the production of fertilizers such as mineral biochar and organic humus. The role of these fertilizers is particularly important for regions that face the challenge of insufficient fertility of the zonal soil type, a concern that is common in some mountainous regions. The goal of the study is to develop a method and analyze the results of its application to successfully solve the problem of excess chicken manure by producing a substance that improves the physicochemical properties of sod-podzolic soils and increases their biological efficiency. Materials and methods. The laboratory facilities of the Ecosystem Research Center at St. Petersburg Mining University were used in this study. The physicochemical properties of soils and plants were analyzed based on a standard method for determining the organic content of soils using gravimetric, thermogravimetric, and optical emission spectrometry methods. Results and discussion. Given the relatively low fertility of sod-podzolic soils, which are common in mixed forest regions, the article proposes a modified version of composting as a priority for processing poultry manure. This method accelerates the biochemical processes of manure decay by using a specially bred subspecies of the earthworm Eisenia fetida. The article provides a detailed description of this method for processing poultry manure, which results in the production of an organic fertilizer. To evaluate the effect of the biofertilizer produced by the proposed method on the physicochemical properties of sod-podzolic soils and the plants grown on them, we conducted an experiment involving the addition of the biofertilizer to the soil, followed by sowing ryegrass and spring onion seeds, followed by an analysis of soil and plant samples. The results of the experiment showed that the presence of the biofertilizer in the soil increases its moisture content, improves moisture retention, and reduces ash content. The addition of the biofertilizer significantly increases the contents of humus, organic carbon, total nitrogen, phosphorus, and potassium, also promoting the removal of heavy metals. The use of the proposed biofertilizer enhances the uptake of carbon, nitrogen, and potassium into plants. The proposed method is adapted to residential area conditions and can be used by agricultural companies in various regions of Russia. A future line of research includes experiments to find the rational biofertilizer application rates for growing more common vegetable and grain crops in soils of different types. Conclusions. The study has developed a comprehensive method for investigating the processes of transfer of organic matter and chemical elements from the proposed biofertilizer into soils and plants. This method includes laboratory tests of the physicochemical properties of soils before and after the experiment and those of fertilizers and plants after the experiment. The results demonstrate that the presence of the biofertilizer in dry sod-podzolic soils increases their fertility and improves the physicochemical properties of both the soils and the plants. Resume. The proposed method is adapted to residential area conditions and can be used by agricultural companies in various regions of Russia. A future line of research includes experiments to find the rational biofertilizer application rates for growing more common vegetable and grain crops in soils of different types.

Методические подходы к определению географического происхождения вин. Обзор

Wines with a clear geographical origin are more attractive for customers. The geographical origin of wine is stated on its label, but no official standards guarantee its reliability. The present research objective was to analyze the existing methodological approaches to wine authentication.
 The study featured domestic and foreign publications indexed in Dimensions and Elibrary in 2017–2022 with such keywords as wine authentication, geographical origin of wine, and chemometrics.
 The research revealed no single methodological solution to wine authentication because food science knows a wide range of parameters, methods, analytical equipment, and data processing models. Chemometric methods are reliable because they are able to process large arrays of analytical research results structured in a data bank using the so-called fingerprint principle. They involve 2–65 markers that are individual for each geographical region, country, zone, or terroir. Another promising method is the quantitative and qualitative nuclear magnetic resonance spectroscopy (qNMR) of protons 1H and deuterium 2H(D) nuclei, as well as other elements (13C, 17O, 31P, 14N). The review resulted in an integrated approach based on a combination of isotopic testing with cation-anionic profiling. The analytical support involved the methods of atomic absorption and atomic emission spectroscopy, spectrometry with inductively coupled plasma, isotope ratio mass-spectrometry, and quantitative and qualitative nuclear magnetic resonance spectroscopy. This combined approach could provide background for an all-Russian state standard with a single algorithm for wine authentication tests. 
 The new approach will be used to develop enochemical profiles of wines from a particular region, as well as to choose the most effective chemometric models for geographical authentication.

Assessment of concentration of the potentially toxic elements and associated human health risk from particulate matter exposure along road intersections in Ibadan, southwestern Nigeria

The harmful health effect of suspended particulate matter (PM10) is mostly associated with its mass concentrations and chemical compositions. Therefore, this study focuses on the determination of the particulate matter (PM10) concentrations and their potentially toxic elements (PTEs) composition from different road networks in Ibadan southwestern, Nigeria. In addition, human health risk assessment was estimated from the PTE data. The PM10 samples were collected from different road networks such as national highway roads (NHR), inner-city major roads (ICR), and remote roads (RRD) in Ibadan, Nigeria. The sampling was carried out with a high-volume air sampler (model #15000 manufactured by Science Resource, Walboro, USA) with a PM10 cut-off on a Whatman cellulose filter during the harmattan period. The PM10 concentrations and PTEs compositions (Al, Ba, Cd, Cu, Fe, La, Mo, Mn, Ni, Pb, V, and Zn) were determined by gravimetry and inductively coupled plasma-optical emission spectrometry (ICP-OES) methods (VISTA-MPX manufactured by Varian Incorporation), respectively. The PM10 concentrations in all three road networks were more than 3 folds higher than World Health Organization (WHO), United State Environmental Protection Agency (USEPA), and United Kingdom Environmental Protection Agency (UKEPA) standards (50 µg/m3) for 24 h. The maximum average contents of Ba, Cd, Cu, La, Mn, Pb, and V, were observed at NHR, while that of Al, Fe, Mo, and Zn, were found at ICR. The principal component analysis (PCA) showed that PC1 (Ba, Cd, Cu, La, Mo, Pb, and V) and PC4 (Zn) were characterised by elemental markers of both exhaust emission and non-exhaust emissions, while PC2 (Mn) and PC3 (Al, Fe) were characterised by crustal elements. The Enrichment factor (EF) analysis classified all the PTEs as moderately to very highly enriched, especially in NHR and ICR, except Al, Fe, and to some extent Mn. Both the maximum and average hazard quotient (HQ) levels of Cd, Cu, Mn, Pb, and Zn were < 1, which was within the permissible level. Also, the carcinogenic risk (CR) was also within the permissible limit.

Detection of sulfur mustard simulants using the microwave atmospheric pressure plasma optical emission spectroscopy method.

Sulfur mustard (SM) is one kind of highly toxic chemical warfare agent and easy to spread, while existing detection methods cannot fulfill the requirement of rapid response, good portability, and cost competitiveness at the same time. In this work, the microwave atmospheric pressure plasma optical emission spectroscopy (MW-APP-OES) method, taking the advantage of non-thermal equilibrium, high reactivity, and high purity of MW plasma, is developed to detect three kinds of SM simulants, i.e., 2-chloroethyl ethyl sulfide, dipropyl disulfide, and ethanethiol. Characteristic OES from both atom lines (C I and Cl I) and radical bands (CS, CH, and C2) is identified, confirming MW-APP-OES can preserve more information about target agents without full atomization. Gas flow rate and MW power are optimized to achieve the best analytical results. Good linearity is obtained from the calibration curve for the CS band (linear coefficients R 2 > 0.995) over a wide range of concentrations, and a limit of detection down to sub-ppm is achieved with response time on the order of second. With SM simulants as examples, the analytical results in this work indicate that MW-APP-OES is a promising method for real-time and in-site detection of chemical warfare agents.

Study of matrix interference in the determination of selenium and tellurium in ICP-AES in metallurgical materials

The content of selenium and tellurium used in steels and alloys as alloying additives is strictly regulated by the current state standards. The methods of analysis used in state standards are often lengthy and laborious and do not provide their simultaneous determination. Development of alternative methods for the determination of selenium and tellurium in metallurgical materials using modern analytical equipment is an urgent goal. The method of atomic emission spectrometry with inductively coupled plasma (ICP-AES) is widely used in analysis of metallurgical materials. However, the components of the sample base can significantly affect the results of ICP-AES analysis. We present the results of theoretical and experimental study of the effect of the components of the base of samples of metallurgical materials (iron, nickel, chromium, molybdenum, cobalt, copper, tungsten) on the spectral analytical lines of selenium and tellurium. Thermodynamic modeling was used for theoretical prediction of the processes occurring during atomization of the analyzed solutions in argon plasma. It is shown that matrix non-spectral noise on the selenium line is attributed to chromium (at chromium concentrations above 50 mg/dm3), whereas the matrix non-spectral noise on the tellurium line is not observed. It is also shown experimentally that the spectral lines of selenium and tellurium are not free from spectral overlaps attributed to macrocomponents (iron, nickel, chromium, molybdenum, cobalt, copper and tungsten). To reduce the limits of detection and improve the reliability of ICP-AES determination of selenium and tellurium, it is necessary to separate them from the components of the sample base.

Evaluation of an Inductively Coupled Plasma–Atomic Emission Spectrometry (ICP-AES) Method for the Determination of Macro and Microelements in Trifolium L. Species

This study aimed optimizes the inductively coupled plasma–atomic emission spectrometry (ICP-AES) conditions for the determination of macro and microelements in the flowers and leaves of Trifolium species. After the optimization of instrumental parameters, plasma robustness was achieved under the following conditions: RF power 1350 W, nebulizer flow rate 0.5 L min−1, coolant gas flow rate 12 L min−1, auxiliary gas flow rate 0.5 L min−1, flush pump rate 100 rpm, analysis pump rate 50 rpm, sample flow 0.5 mL min−1, and sample uptake delay 30 s. The limits of detection (LOD) and limits of quantification (LOQs) were lower than literature values. The most abundant microelement in leaves is Ca, followed by K, Mg, P, and Na, and in flowers was K, followed by Ca, P, Mg, and Na. The average contents of microelements decreased in the orders S > Fe > Si > Al > Zn > Mn > Cu > Ni > Co > Pb > Cr > As > Cd for flowers and S > Fe > Si > Mn > Al > Zn > Cu > Ni > Co > Pb > Cr > As > Cd for leaves. Chemometrics were used for grouping samples based upon the elemental contents.