Instrumental Methods Of Analysis Research Articles

Evaluating the detection of barbiturates in dried blood spots: A comparative analysis using gas chromatography-mass spectrometry, gas chromatography-tandem mass spectrometry, and liquid chromatography-tandem mass spectrometry with different extraction methods

Rapid and accurate characterization and quantitation of blood barbiturates and their combination drugs are very important for the clinical treatment of acute barbiturate poisoning. A comparison of dried blood spot (DBS) and traditional liquid-liquid extraction (LLE) in the pre-treatment stage, as well as a comparison of gas chromatography-mass spectrometry (GC–MS), gas chromatography-tandem mass spectrometry (GC–MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) as instrumental analysis methods, revealed differences in the analysis results of barbiturates and their combination drugs under different conditions. Based on these findings, we introduce a DBS-GC–MS/MS method. The developed and validated method showed good selectivity, sensitivity (LOD: 0.1 μg mL−1, LOQ: 0.2 μg mL−1), linearity (R2>0.9992), trueness (<15 %, except for carbamazepine, at 29.4 %), and precision (<15 %). Recovery was also good for most target compounds, but significant matrix effects were evident. Compared with the LLE method, the DBS method has the benefits of easy sample collection, storage, and transport, as well as simple pre-treatment and reduced reagent and energy consumption. Compared to LC-MS/MS, GC–MS/MS requires no switching between positive and negative ion modes and uses the MRM detection mode, meaning that more information about the sample compounds can be obtained in less analysis time. Using actual sample analysis, we have demonstrated the advantages of the DBS-GC–MS/MS method for the qualitative and quantitative analysis of barbiturates and poisoning events due to combinations of these drugs. Comparison of the three instruments and the two treatment methods revealed their analysis characteristics. From the perspective of practical application, the broad practical value and advantages of DBS should be embraced in more applications, and future analytical laboratory development should continue to recognize GC–MS/MS as a useful supplement to LC-MS/MS.

Dissolution‐Recrystallization: A Novel Mechanism for Fluorochromic Detection of Th4+ Using Color‐Tunable Luminescent Metal–Organic Frameworks

AbstractThorium, a predominant actinide in the Earth's crust, presents significant environmental and health risks due to its radioactive nature. These risks are particularly pronounced during the mining and processing of monazite for rare earth elements (REEs), which contain substantial thorium concentrations. Current instrumental analysis methods for thorium, offer high accuracy but require laborious sample preparations and expensive instruments, making them unsuitable for on‐site analysis. Herein, we present a class of color‐tunable luminescent lanthanide‐based metal–organic frameworks (Ln‐MOFs) as fluorochromic sensors for Th4+ cations. Utilizing a heterobimetallic Eu3+/Tb3+ doping strategy, the luminescence colors of EuxTb1‐x‐BDC‐OH can be finely tuned from red, to orange, and to green. More intriguingly, the higher Lewis acidity of Th4+ facilitates the transformation of EuxTb1‐x‐BDC‐OH into a UiO‐type Th‐MOF via a dissolution‐recrystallization mechanism. This process results in a gradual reduction of characteristic Ln3+ emissions and the emergence of blue color ligand‐based fluorescence, thereby leading to selective fluorochromic responses with increasing Th4+ concentrations and enabling visible detection of Th4+ cations. Additionally, a custom‐built portable optoelectronic device is fabricated, which directly converts luminescence colors into red‐green‐blue (RGB) values. This device enables easy quantification of Th4+ concentrations without the need for complex instrumentation.

Dissolution-Recrystallization: A Novel Mechanism for Fluorochromic Detection of Th4+ Using Color-Tunable Luminescent Metal-Organic Frameworks.

Thorium, a predominant actinide in the Earth's crust, presents significant environmental and health risks due to its radioactive nature. These risks are particularly pronounced during the mining and processing of monazite for rare earth elements (REEs), which contain substantial thorium concentrations. Current instrumental analysis methods for thorium, offer high accuracy but require laborious sample preparation and expensive instruments, making them unsuitable for on-site analysis. Herein, we present a class of color-tunable luminescent lanthanide-based metal-organic frameworks (Ln-MOFs) as fluorochromic sensors for Th4+ cations. Utilizing a heterobimetallic Eu3+/Tb3+ doping strategy, the luminescence colors of EuxTb1-x-BDC-OH can be finely tuned from red, to orange, and to green. More intriguingly, the higher Lewis acidity of Th4+ facilitates the transformation of EuxTb1-x-BDC-OH into a UiO-type Th-MOF via a dissolution-recrystallization mechanism. This process results in a gradual reduction of characteristic Ln3+ emissions and the emergence of blue color ligand-based fluorescence, thereby leading to selective fluorochromic responses with increasing Th4+ concentrations and enabling visible detection of Th4+ cations. Additionally, a custom-built portable optoelectronic device was fabricated, which directly converts luminescence colors into red-green-blue (RGB) values. This device enables easy quantification of Th4+ concentrations without the need for complex instrumentation.

Detection methods for antibiotics in wastewater: a review.

Antibiotics are widely used as fungicides because of their antibacterial and bactericidal effects. However, it is necessary to control their dosage. If the amount of antbiotics is too much, it cannot be completely metabolized and absorbed, will pollute the environment, and have a great impact on human health. Many antibiotics usually left in factory or aquaculture wastewater pollute the environment, so it is vital to detect the content of antibiotics in wastewater. This article summarizes several common methods of antibiotic detection and pretreatment steps. The detection methods of antibiotics in wastewater mainly include immunoassay, instrumental analysis method, and sensor. Studies have shown that immunoassay can detect deficient concentrations of antibiotics, but it is affected by external factors leading to errors. The detection speed of the instrumental analysis method is fast, but the repeatability is poor, the price is high, and the operation is complicated. The sensor is a method that is currently increasingly studied, including electrochemical sensors, optical sensors, biosensors, photoelectrochemical sensors, and surface plasmon resonance sensors. It has the advantages of fast detection speed, high accuracy, and strong sensitivity. However, the reproducibility and stability of the sensor are poor. At present, there is no method that can comprehensively integrate the advantages. This paper aims to review the enrichment and detection methods of antibiotics in wastewater from 2020 to the present. It also aims to provide some ideas for future research directions in this field.

Generation of specific aptamers for constructing CoOOH nanozymes-based colorimetric aptasensor for detection of fleroxacin in milk

The misuse or abuse of fleroxacin (FLE) in livestock and aquaculture can result in elevated levels of FLE in animal-derived foods, posing significant health risks to humans. Detection of FLE has been relying on instrumental analysis methods that need expensive equipment and longer analysis time. Herein we report the first isolation of two specificity aptamers against FLE (FLE-9 and FLE-51) by capture-SELEX, characterized them well and explored the binding mechanism. Furthermore, FLE-9 was selected to construct a CoOOH@Apt based biosensor. The catalytic activity of the biosensor was evaluated using the Michaelis equation, revealing a Vmax of 4.87×10−8 M s−1 and a Km of 0.11 mM. These results suggest that the affinity of CoOOH@Apt is higher than that of CoOOH nanozymes. In the present of FLE, the aptamer FLE-9 specifically binds to FLE, distancing itself from CoOOH nanozymes and thereby reducing the catalytic activity of the biosensor. Finally, the label-free colorimetric aptasensor was successfully applied to detect FLE, with a detection limit of 4.26 ng/mL. The recovery rates ranged from 96.70 % to 101.70 %, with a relative standard deviation (RSD) below 3.02 %. This study presents promising probes and a novel strategy for the determination of FLE in milk samples, contributing to improved food safety monitoring.

Methods for analysis and monitoring of heavy metals in the environment

This review surveys capabilities of modern instrumental analytical methods that provide low limits of detection for a wide range of elements. Some elements have their own toxic forms, so their identification is of particular importance. Researchers pay increased attention to the content of cadmium and lead due to their high immediate and delayed toxicity.It should be noted that those instrumental methods of analysis that are used to determine these important ecotoxicants are often used to determine other heavy metals. The following objects of analysis are considered – natural, river, sea waters; brines; bottom sediments; plants, including medicinal ones; precipitation; soil; as well as whole blood and blood serum; hair and animal fur; animal organs and tissues. Special attention is paid to eliminating matrix influences and reducing limits of detection using concentration procedures. Various types of extraction, sorption, precipitation, chemical transformation (hydride generation, etc.) are considered and applied to biological and environmental objects.The capabilities of modern instrumental methods of analysis for the determination of heavy metals and important ecotoxicants are considered and compared – single‐element (ETAAS, IVA, etc.) and multi‐element (ICP AES, ICP MS, XRF, etc.). The data is structured in the form of a table, which shows specific analysis methods, indicating the method of sample preparation and/or features of instrumental determination, a list of elements to be determined and the limits of detection.

Development and application of a comprehensive measurement equation for the direct comparator standardization method of Instrumental Neutron Activation Analysis

A comprehensive model equation for the measurement of elemental mass fractions in solid materials using the direct standardization method of Instrumental Neutron Activation Analysis was developed. The extensive modelling established for the single comparator standardization was revised and changed for the direct standardization to obtain a complete mathematical description of the measurand by physical and chemical quantities having dimensions in SI units. The model equation is presented both in case measurement and standard samples are measured in the same γ-counting position and in different γ-counting positions. The first was successfully applied for the quantitative determination of As mass fraction in a seafood matrix with a percent level relative uncertainty. The SI traceability of the result is established by a traceable standard via the measurement equation and the uncertainty budget compiled to highlight the input quantities that contribute most to the combined uncertainty.

Synthesis of phenyl esters 2-oxo-2H-1-benzopyran-3-carboxylic acids as promising antimicrobial agents

Corresponding chloroanhydrides were synthesized by the interaction of coumarin-3-carboxylic and 6-methoxycoumarin-3-carboxylic acids with an excess of thionyl chloride under heating. Due to the quantitative yields and the formation of volatile products within the reaction, chloroanhydrides were used without additional purification in acylation of substituted phenols for the synthesis of phenyl esters of 2-oxo-2H-1-benzopyran-3-carboxylic acids. The reaction was carried out by heating in anhydrous dioxane environment in the presence of pyridine as a catalyst. The structure of the obtained esters was proven using instrumental methods of analysis. The antimicrobial and antifungal activity of the synthesized compounds was studied in vitro by the method of two-fold serial dilutions in liquid and solid nutrient environments. Antimicrobial activity screening showed that the synthesized esters have a moderate activity against gram-negative microorganisms and C. albicans. It was found that the 4-methyl-2-chlorophenyl ester of coumarin-3-carboxylic acid had the greatest bacteriostatic activity against Ps. aeruginosa and Pr. vulgaris, 2-chlorophenyl ester of coumarin-3-carboxylic acid against Ps. aeruginosa and E. coli, coumarin-3-carboxylic acid 4-hydroxyphenyl ester against Pr. vulgaris, and coumarin-3-carboxylic acid 2-isopropyl-5-methylphenyl ester against E. coli at a concentration of 31.25 g/ml. 2-Chlorophenyl ester also showed a bactericidal effect against E. coli. The synthesized compounds also have an antifungal effect against the C. albicans. strain used in the experiment. Thus, 4-methyl-2-chlorophenyl ester, 4-fluorophenyl ester, 4-hydroxyphenyl ester, 2,3-dihydroxyphenyl ester, 2-isopropyl-5-methylphenyl ester of coumarin-3-carboxylic acid are active at a concentration of 31.25 g/ml.

SAFETY ASSESSMENT OF A RANGE OF PLANT METABOLIC TOVES – ADVANCED GEROPROTECTORS IN VIVO RESEARCH

Background. Ageing is associated with progressive impairment of physical functions and increased risk of age-related chronic diseases. Polyphenols such as mangiferin, quercetin and trans-cinnamic acid are also used for the treatment and prevention of chronic diseases. Toxicological research was important in biomedical research, as some high-dose extracted polyphenols could contribute to the development and progression of cancer and other diseases. This study is aimed at assessing toxicological safety of previously isolated phenolic compounds from plants of the Siberian Federal District. Materials and methods. Rodents have been chosen as the model organism. The study of mutagenic and antimutagenic properties was carried out using a micronuclear test of bone marrow cell. Cytotoxicity in vitro was assessed using the MTT test. Results. Polyphenols studied at doses of 50.0 and 100.0 mg/kg are not mutagenic. Mangiferri and quercetin at a dose of 50.0 mg/kg do not have anti-thagenic effects. In this case, trans-cinnamic acid in the same concentration has antimutagenic effect. Mangiferin in concentrates from 4.2 to 16.7 ug/ml has a cytotoxic effect. Trans-cinnamic acid is not cytotoxic (at 2.1-33.3 ug/ml). Quercetin has a cytotoxic effect in concentrations of 0.21 and 1.67 ug/ml, and at concentrations of 3.33 ug/ml increases the viability of splenocytes, presumably due to antioxidant properties. Conclusion. Safety or low toxicity is a decisive advantage of the continued use of polyphenols as advanced heroic flow agents. Further study of biologically active substances (mangiferin, quercetin and trans-cinnamic acid) has been found to be ce-woody. The work was carried out by the state task on the topic «Development of biologically active additives consisting of metabolites of plant objects in vitro to protect the population from premature aging» (project FZSR-2024-0008) using the equipment of Center of Collective Use «Instrumental methods of analysis in the field of applied biotechnology» on the basis of KemSU.

Association between gut microbiota and hepatocellular carcinoma and biliary tract cancer: A mendelian randomization study

BACKGROUND An increasing number of studies have begun to discuss the relationship between gut microbiota and diseases, yet there is currently a lack of corresponding articles describing the association between gut microbiota and hepatocellular carcinoma (HCC) and biliary tract cancer (BTC). This study aims to explore the relationship between them using Mendelian randomization (MR) analysis method. AIM To assess the relationship between gut microbiota and HCC and BTC. METHODS We obtained Genome-wide association study (GWAS) data for the gut microbiome from the intestinal microbiota genomic library (MiBioGen, https://mibiogen.gcc.rug.nl/ ). Additionally, we accessed data pertaining to HCC and BTC from the IEU open GWAS platform (https://gwas.mrcieu.ac.uk/ ). Our analysis employed fundamental instrumental variable analysis methods, including inverse-variance weighted, MR and Egger. To ensure the dependability of the results, we subjected the results to tests for multiple biases and heterogeneity. RESULTS During our investigation, we discovered 11 gut microbiota linked to an increased risk to BTC and HCC. The former included the genus Eubacterium hallii group (P = 0.017), Candidatus Soleaferrea (P = 0.034), Flavonifractor (P = 0.021), Lachnospiraceae FCS020 (P = 0.034), the order Victivallales (P = 0.018), and the class Lentisphaeria (P = 0.0.18). The latter included the genus Desulfovibrio (P = 0.042), Oscillibacter (P = 0.023), the family Coriobacteriaceae (P = 0.048), the order Coriobacteriales (P = 0.048), and the class Coriobacteriia (P = 0.048). Furthermore, in BTC, we observed 2 protective gut microbiota namely the genus Dorea (P = 0.041) and Lachnospiraceae ND3007 group (P = 0.045). All results showed no evidence of multiplicity or heterogeneity. CONCLUSION This study explores a causal link between gut microbiota and HCC and BTC. These insights may enhance the mechanistic knowledge of microbiota-related HCC and BTC pathways, potentially informing therapeutic strategies.

A methodological study of the hardness of cooked Chinese noodles based on the texture analyzer

Abstract A generic instrumental analysis method, matched with sensory evaluation, for the hardness test of Chinese dried noodles after cooking, was established in this study. The cut and compression mode was compared at first, followed by an analysis of the hardness response curve obtained from cut code with three-stage. Then the reliability of this method was verified with 20 commercially available noodles. Results showed that the hardness difference between the two samples obtained using compression mode was only 0.087 %. In contrast, a 6.34 % difference was obtained using cut mode with the hardness value of 296.12 ± 6.10 g and 278.47 ± 12.22 g, respectively. Three parameters, including initial hardness (F 1), material hardness (K), and final hardness (F 2), were extracted from the shear curve to characterize the hardness of cooked noodles. A ranking difference of F 1, F 2, and K between 20 commercially available noodles was found, which illustrated various characteristics of cooked noodles. In summary, the cut mode was more suitable for determining the hardness of cooked noodles; F 1, F 2, and K, obtained from a three-stage analytical method for the inner and outer hardness of cooked noodles characterization, had excellent performance to match with sensory evaluation.

Phenotyping Wheat Kernel Symmetry as a Consequence of Different Agronomic Practices

The use of instrumental methods of analysis in the assessment of indices that record changes in symmetry in the structure of grains to evaluate the quality of durum and soft wheat grain is currently considered a search tool that will allow us to obtain previously unavailable data by finding correlations associated with differences in the shape and ratio of starch granules in conditionally symmetrical and asymmetrical wheat fruits (kernels) formed in different field conditions and with different genotypes. Indicators that had previously shown their effectiveness were used to analyze the obviously complex unique material obtained as a result of growing under critically unique sowing conditions in 2022, which affected the stability of grain development and filling. For the evaluation, a typical agronomic comparative experiment was chosen, which was used to evaluate the soil tillage practices (fallow, non-moldboard loosening, and plowing) and sowing dates (early and after excessive rainfalls), which made it possible to analyze a wider range of factors influencing the studied indices. The soil tillage methods were found to affect the uniformity of kernel fullness and their symmetry, and the sowing dates did not lead to significant differences. This study presents detailed changes in the shape of the middle cut of a wheat kernel, associated with assessing the efficiency of kernel filling and the symmetrical distribution of storage substances under the influence of external and internal physical factors that affect the formation of the wheat kernel. The data obtained may be of interest to breeders and developers of predictive phenotyping programs for cereal grain and seeds of other crops, as well as plant physiologists.

Extraction Optimization, Structure Analysis and Antioxidant Activity of Polysaccharide from Sanghuangporus baumii

Introduction: In this study, we optimized the extraction process, analyzed the structure and assessed the antioxidant activity of Sanghuangporus baumii polysaccharide (SBP). The present results provide important information for the Sanghuangporus baumii polysaccharides in potential natural antioxidant effects. Background: The extraction and structural analysis of polysaccharides from Sanghuangporus has gained significant attention in the fields of chemistry, medicine, and life sciences. There is great significance in maximizing the extraction of polysaccharides from Sanghuangporus and developing their potential products in a scientific and rational manner. Objective: The study was designed to establish an efficient and practical extraction process for SBP, and then investigated the structure and the antioxidant activity. Methods: The Response Surface Methodology (RSM) based on Box-Behnken design was used to explore the ultrasound-assisted extraction of SBP, and the structure of SBP was studied by ultraviolet spectroscopy, infrared spectroscopy and other instrumental analysis methods. The total antioxidant capacity of SBP was studied by the Ferric Reducing Ability of Plasma (FRAP) method, and the scavenging capacity of ABTS+·, DPPH· and OH· was carried out as the index to investigate its antioxidant activity in vitro. Results: The statistical analysis results showed that the optimal conditions for extracting SBP were an ultrasound time of 20.74 min, ultrasound power of 268.40 W and material-liquid ratio of 1:25.71. Under optimal conditions, the experimental yield of SBP was 3.36 ± 0.01%. The RSM optimization process was applied to the experiment of complex enzyme extraction of SBP, and the yield increased to 4.72 ± 0.03%. Structural analysis showed that SBP mainly consisted of glucose, a small amount of mannose and galactose, and the molecular weight distribution was uneven, mainly concentrating in the three parts of 24.5,6.4,2.5 kDa. Moreover, SBP exhibited dose-dependent and strong reducing power and radical scavenging activity. For DPPH·, ABTS+· and OH· radical scavenging assays, IC50 values were 1.505 ± 0.050 mg/ml, 0.065 ± 0.036 mg/ml and 0.442 ± 0.007 mg/ml, respectively. Conclusion: In the present study, a β-linked heteroglucan (SBP) was extracted using the optimized process combining enzymes from the fruiting bodies of Sanghuangporus baumii. SBP exhibited effective and dose-dependent antioxidant activities. Our findings were of great value in terms of developing polysaccharides with potential natural antioxidants.

Development of methods for assessing the safety of specialized food products

Control of the safety of specialized food products (SFP) as an actively developing market segment requires constant attention of researchers due to previously unknown risks, which makes it important to develop new approaches to solving this problem. The main factors infl uencing the SFP safety assessment are considered, and the advantages of several promising methods of instrumental analysis are characterized.

Impact of rice variety, cooking equipment and pretreatment method on the quality of lightly milled rice

Lightly milled rice is a healthier choice compared to refined white rice. In this study, the effects of variety, cooking equipment and pretreatment method on the quality of six varieties of lightly milled rice from China after cooking was investigated through physics, chemistry and instrumental analysis method. Nanjing-No.5055 has the best eating quality, Xiadao-No.1 has higher appearance score, and Fengliangyouxiang-No.1 has the lowest glycemic index. Compared with microwave oven and electric cooker, steamer has a more significant positive impact on component retention, eating quality and sensory quality, but the former has lower cooking time and higher glycemic index. Soaking can effectively improve the water absorption rate, thus reducing hardness. Cleaning affects component retention but is beneficial for sensory quality. The most obvious variation in organizational structure can be observed in the steamer and soaking processes. These findings could serve as a valuable reference for the processing of lightly milled rice.

ОСОБЕННОСТИ ПРЕПОДАВАНИЯ ДИСЦИПЛИНЫ ТОКСИКОЛОГИЧЕСКАЯ ХИМИЯ СТУДЕНТАМ, ОБУЧАЮЩИМСЯ ПО СПЕЦИАЛЬНОСТИ 32.05.01 МЕДИКО-ПРОФИЛАКТИЧЕСКОЕ ДЕЛО

The question of organizing the learning process for students of the medical and preventive faculty at the Institute of Pharmacy is significant for the teacher. Compared to students of the Faculty of Pharmacy, they do not have sufficient knowledge in chemistry, so it is necessary to search for additional teaching methods. After the transition to training according to the Bologna system, classroom lessons were reduced and student independent work was increased. The classroom load of students is 36 hours a week, leaving almost no time for independent work. Because students are poorly prepared in chemistry, instructors typically upgrade their knowledge to proficiency levels by providing preparatory materials in toxicological chemistry. According to the curriculum in toxicological chemistry, 42 contact-hours of work are allocated (10 hours of lectures + 32 hours of seminars and practical classes). How can a teacher at the Institute of Pharmacy motivate a medical student to study a medical discipline? One of the possible ways to increase interest in this way is through research work in a medical laboratory and, as an option, involving students in joint scientific work at university departments. The training was organized on the basis of lectures, seminars (round table) and practical exercises. The lectures covered only problematic and review material intended to test theoretical knowledge about compliance with remote disciplinary measures. At the Institute of Pharmacy of Kazakh State Medical University, the round table method was used when conducting seminars. Students go into the topic in advance. When preparing for employment, use scientific and professional information from a variety of sources. In practical classes, students acquired sample preparation skills for identifying toxic substances, developed skills in isolating toxic substances, and used chemical and instrumental methods of analysis. Students mastered modern physicochemical and chromatographic methods of analysis used in the system of general and private screening of chemical substances. During the last lesson, educational and research work is carried out. Based on the results of mastering the discipline, students of the Faculty of Preventive Medicine acquired a colossal amount of knowledge, which they will later use in practical work.

FT-IR combined with oscillatory rheology: How to evaluate chemical structure of ester derivatives of MA-containing compatibilizers

Ester derivatives of experimental olefin-maleic anhydride copolymers synthesized at the University of Pannonia have been investigated by both classical and instrumental analytical methods that contribute to a deeper understanding of how that type of additives functions as compatibilizers for plastics and rubbers.Titration-based acid and saponification numbers have provided limited information about the chemical structure of the experimental copolymer compounds. A prompt, precise and low-cost method or combination of methods has been required to access to the ratio of the various derivatives not only straight after esterification but also for quality control during long-term storage considering the even stricter sustainability aspects either. Reproduction and scaling-up synthesises can be also followed by the combined measuring techniques of Fourier-transform infrared spectroscopy (FT-IR) and oscillatory rheometry. Structural changes occurred in the additives could be followed through monitoring their Ester Indices (EI) during the measurement, which can be connected also to the long-term properties. Experimental additives (AD) like AD-1 and AD-2 types with lower EI values of 21.5 % and 32.1 %, respectively, resulted in higher upper limits of the linear viscoelastic (LVE) range (15 % and 10 %). Conversely, the higher EI values of AD-3 and AD-4 led to significantly lower or even immeasurable upper limits of the LVE range. Additives with solid behaviour showed slight dependence on frequency above the crossover point that indicated strong connections disappearing.

Optimization and Applications of Instrumental and Preconcentration Neutron Activation Analysis Methods for Rapid Determination of Selected REE by Utilizing their Short‐Lived Activation Products**

AbstractDetermination of Rare Earth Elements (REEs) using spectroscopic methods is challenging. Conventional Instrumental Neutron Activation Analysis (INAA) method utilizing Pneumatic Carrier Facility (PCF) of Dhruva research reactor has been optimized with the short‐lived isotopes such as 161Gd, 165mDy and 153/155Sm for quantification of Gd, Dy and Sm respectively. Such isotopes are difficult to observe by conventional INAA with longer cooling periods owing to their very short half‐lives (1–3 mins). In this work, such isotopes are not only observed but also utilized as activation product for rapid determination of these REEs. The standardized method has been utilized for the first time in liquid samples involving nuclear fuel like U3O8 wherein TBP/n‐dodecane has been applied for chemical separation of Uranium prior to analysis. The INAA method has also been applied for validating the stoichiometry of Gd in Gd3+ co‐doped Zn2P2O7:Tb3+ green emitting solid‐state phosphors, which plays a very pivotal role in sensitizing the terbium ion in its performance for solid state lighting. We believe with huge current demand of REEs in research, science and technology; INAA can be a game changer wherever needed for quantification with high precision and accuracy and can also be extended to other REEs of interest.

Engine Oil Degradation in the Real-World Bus Fleet Test Based on Two Consecutive Operational Intervals

The literature on the subject and the results of numerous research experiments indicate that single replacement cycles do not reflect the actual state of oil quality in the context of its degradation. Monitoring the operational quality of the oil in several successive stages allows for a more accurate diagnosis of the optimal oil change time. Therefore, it was decided to investigate the relationship between two consecutive periods of changing the operating oil in an engine. Comparative tests of seven buses included in the fleet were carried out. An important division criterion was taken into account—the operation of city and intercity buses. The HDXRF instrumental chemical analysis method was used to determine changes in the content of abrasive metals, and additives in engine oils. Additionally, the oxidation, nitration, sulfonation, and soot content were assessed using infrared spectroscopy (FTIR) based on the ASTM E2414-10 standard and kinematic viscosity at 40 °C and 100 °C using a Stabinger viscometer according to ASTM D7042. The course of these changes was analyzed in terms of their dynamics. The comparative study aimed to identify trends and sources of differences between the tested oils, as well as to demonstrate the number of exceedances of limit values for the selected parameters.

Prospects of the development and harmonization of hygienic standardization taking into account the risk of odour in the ambient air

Introduction. The presence of a specific odour in the ambient air in the areas where various enterprises are located with formal compliance with environmental legislation indicates the need to update the methodology of hygienic standardization of odourous substances.&#x0D; The purpose of the work is to analyze modern methods of the establishment of standards for odourous complex multicomponent mixtures of substances in the atmospheric air and substantiate ways to harmonize them in this field of knowledge.&#x0D; Materials and methods. The paper systematizes existing approaches to regulating the quality of atmospheric air in areas where odourous emissions sources are located, taking into account certain provisions of regulatory and methodological documents, publications on approaches, and criteria for quantitative sanitary and hygienic assessment of the quality of the environment and public health, as well as the authors’ long-term experience in this field.&#x0D; Results. The basic principles of hygienic standardization of the permissible content of odorous mixtures of substances in the atmospheric air taking into account their odour are formulated. The substantiation of hygienic standards is carried out with the allocation of substances identified as priority (indicator), based on the results of studying the production technology and the formation of emissions, olfactory properties of the mixture under experimental conditions, with the possibility of monitoring the established standard in atmospheric air by certified instrumental methods of analysis.&#x0D; Limitations. The limitations of the study are due to the fact that this article does not fully reflect the issues of the development of the entire atmospheric air quality management system taking into account the risk of odour outside the focus of this work, which will be covered in the preparation of the following articles.&#x0D; Conclusion. The ongoing process of harmonization of domestic and foreign approaches used in hygienic standardization including the field of regulation of atmospheric air pollution by specific odours makes it necessary to significantly expand approaches to the issues of rationing and assessment of environmental pollution by complex multicomponent emissions of odour-source enterprises taking into account modern experience.