Optical Emission Spectrometer Research Articles

A screening study of elemental composition in legume (Fabaceae sp.) cultivar from Serbia: Nutrient accumulation and risk assessment

The study is the first analytical approach to evaluate thirteen elements’ profiles of 4 different species (Phaseolus spp., Vicia spp., Pisum spp. and Lathyrus spp.) comprising 38 varieties of legumes cultivated in Serbia. The inductively coupled plasma with an optical emission spectrometer (ICP-OES) was used to determine the levels of macro-, micro- and trace elemental contents, namely, P, K, Ca, Mg, Fe, Cu, Zn, Mn, Cd, Pb, Ni, Cr and As, after microwave-assisted digestion. MANOVA was utilized to reveal significant differences in elemental composition within and between groups, while PCA to reveal the underlying patterns. Among the macroelements, the most abundant was K (8980.7–14177.4 mg kg−1), followed by P, Mg and Ca, being the highest in Phaseolus spp. The data revealed that the studied legumes generally contained a high amount of Zn and Fe, with Lathyrus spp. being the richest in Zn. The mean concentration of trace elements in the analyzed legume samples was in the following order: Ni (24.2–57 mg kg−1) > Cr (0.8–4.1 mg kg−1) > Pb (0.07–1.2 mg kg−1) > Cd (0–0.07 mg kg−1). The determined Pb and Cd contents in all cultivars exceeded the set maximum limits by European and Serbian legislation, having a potential for human health risk. Pattern recognition techniques applied to the data did not distinguish among the species, revealing a similar elemental profile. In conclusion, this study highlights legumes as an extremely valuable source of macro- and microelements, but also the importance of monitoring the level of heavy metals in this commonly consumed foodstuff.

Zirconium sponge production: an integrated approach for chemical characterization of process intermediates using ICP-OES

Abstract The present paper discusses about the method developed for complete chemical characterization of Zirconium Washed and Dried Frit (WDF) and Reactor Grade ZrO2 powder which includes nonmetallic element sulphur using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Studies have been carried-out on several important aspects of method development such as effect of matrix on determination of analytes, removal of matrix using different solvents, selection of interference free & sensitive wavelengths, calibration strategies like internal standard & standard addition, optimization of several instrumental parameters which includes RF power, plasma gas flow, nebulizer gas flow, nitrogen purging etc., and are discussed. A % RSD of less than 1 % for Zr and up to 3 % for other elements has been achieved in this method. The developed method has been validated using standard recovery of spiked real time samples with known amount of reference materials. Integrated approach adopted in the development of this method has resulted in reduction of analytical waste generated and also enabled to give quick analytical feedback to production plant for downstream processing.

Assessing the Bioaccumulation of Heavy Metals in Cabbage Grown under Five Soil Amendments

Increased heavy metal pollution worldwide necessitates urgent remediation measures. Phytoremediation stands as an eco-friendly technique that addresses this issue. This study aimed to investigate the applicability of phytoremediation in agricultural practices. Specifically, to evaluate the impact of five soil amendments (chicken manure, sewage sludge, leaf compost, cow manure, and vermicompost) on three cabbage (Brassica oleracea var. capitata) varieties (Capture, Primo vantage, and Tiara) yield, quality, and the accumulation of Cd, Cu, Mo, Ni, Pb, and Zn in cabbage heads. The bioaccumulation efficiency of cabbage was determined using an inductively coupled plasma–optical emission spectrometer (ICP-OES). Analysis revealed that soil enriched with chicken manure exhibited the highest cabbage yield. Each cabbage variety demonstrated very high bioaccumulation factor (BAF) indicating substantial heavy metal accumulation. These findings underscore the potential of utilizing crops for phytoremediation to mitigate heavy metal pollution. Additionally, the concentrations of metals below the permissible limits suggest that employing crops for phytoremediation can simultaneously ensure food productivity. This study emphasizes the necessity for further research into the use of crops for remediation strategies.

High-Temperature Steam and Atmospheric Oxidation Characteristic of a Heat-Resistant SP2215 Steel

The high-temperature oxidation performance of SP2215 has become an important issue when they were used as superheaters and reheaters exposed to two different high-temperature environments. In this study, the oxidation behavior of SP2215 steel was investigated under steam and an atmosphere of 650–800 °C for 240 h. The microstructural and chemical characterization of the samples were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), a glow discharge optical emission spectrometer (GD-OES), and atomic force microscope (AFM). The kinetic curves of oxidation revealed excellent oxidation resistance under both environments, but significant different oxidation characteristics, oxide film composition, and structure were obvious. In the steam experiment, selective intergranular oxidation was evident at relatively low temperatures, which was attributed to the preference absorption of supercritical water molecules at the grain boundary. Conversely, a double-layer structure of outer Fe2O3 and a small amount of Fe3O4 and inner Cr2O3 was formed uniformly at 800 °C. In the high-temperature atmosphere experiment, a protective chromium film was dominant at 650–700 °C, and a loose multicomponent oxide film was formed at 750–800 °C, primarily consisting of Cr2O3, spinel FeCr2O4, and CuO.

Non-thermal, atmosphere pressure and roll-to-roll plasma treatment for improving the surface characteristics and antistatic solution absorption in polyester fabrics

Here, atmospheric pressure, Roll-to-Roll and non-thermal plasma treatment was utilized to modifying the surface characteristics of polyester fabric. Optical emission spectrometer (OES) of the plasma medium, revealed presence of N and O contained species such as N2, OH and CO that their emission lines were increased with the increase of plasma power. The results of AFM and SEM analysis showed the increased roughness in nano dimensions on the fabric surface. Also, ATR-FTIR analysis exhibited the higher peak intensities of C = O, NH and OH functional groups in the treated sample compared to the parent sample. Contact angle and capillarity tests revealed the increased wettability of fabric after plasma treatment that can be due to the increase of physical (confirmed by AFM and SEM) and chemical (confirmed by ATR-FTIR) changes in the fiber surface. By using the variance analysis of capillary results, the optimum (669/2 m min−1/26n) and average (461w/7m min−1/13n) condition of plasma treatment were determined. Finally, the treated sample absorbed antistatic solution at the much faster rate compared to the parent one which can be an advantage for better chemical treatment of fabrics. Moreover, the antistatic treatment of plasma-modified fiber led to change of its resistance from 9.9 × 1010 to 1.8 × 108 Ω. Also, the same values of surface resistance after 30 days, confirmed the good durability of resistance test.

Experimental study on metal removal characteristics of Zhundong coal to produce ultra-clean coal using acid-alkali method

The large-scale application of coal-based deash carbon materials has put forward growing requirements for the removal technology of ash within coal. Extensive research has demonstrated that the contents of ash and metal elements have a large influence on the performance of the coal-based electrodes made from ultra-clean coal. However, there is a lack of research on the ash and mental elemental removal characteristics of Zhundong coal. In the present study, one kind of Zhundong coal characterized by a comparatively low ash content, was utilized to examine the characteristics of ash and metals removal during the acid-alkali ash removal process. An inductively coupled plasma optical emission spectrometer (ICP-OES) was utilized to analyze the metal element concentrations in the solution during ash removal and the metal element contents within the coal samples. The removal characteristics of metal elements were further analyzed based on the detection results. The experimental results indicate significant improvements in the removal of ash and metals through acid-alkali multi-stage leaching. Under the specific experimental condition here, a two-stage acid-alkali ash removal process achieves coal with the lowest ash content of 1.6% and the removal of 98.0% of Fe, 95.2% of K, and 94.6% of Na, with the removal of Al reaching up to 40%. In addition, the Fe removed in the acid leaching step accounted for 95% of the total amount removed, and adding an acid pretreatment step based on acid-alkali leaching can remove 90.2% of Fe within coal. Both the acid leaching and alkali leaching steps exhibit a certain removal proportion for Al, K, and Na elements, which are closely related to the existing form of these elements within the coal. Iron-containing minerals are mostly acid soluble and distributed on the surface of coal particles. Potassium-containing minerals are mainly alkaline soluble, resulting in a removal rate of over 60% in the alkali leaching step of acid-alkali leaching combined with acid pretreatment. The low removal rate of Al (∼40%) is due to the wide variety of Al-containing minerals, such as kaolin, illite, and aluminates, which are less removed during the reaction with alkali due to temperature limitations. The present study can offer improved knowledge on mineral removal to obtain ultra-clean coal for utilization as function materials.

Heterotrophic Selenium Incorporation into Chlorella vulgaris K-01: Selenium Tolerance, Assimilation, and Removal through Microalgal Cells

Chlorella has been applied in the production of selenium (Se) enriched organic biomass. However, limited information exists regarding heterotrophic selenium tolerance and its incorporation into Chlorella. This study aimed to investigate the potential of using Chlorella vulgaris K-01 for selenium biotransformation. To assess the dose-response effect of Se stress on the strain, time-series growth curves were recorded, growth productivity parameters were calculated, and Gaussian process (GP) regression analysis was performed. The strain’s carbon and energy metabolism were evaluated by measuring residual glucose in the medium. Characterization of different forms of intracellular Se and residual Se in the medium was conducted using inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometer (ICP-OES). The EC50 value for the strain in response to Se stress was 38.08 mg/L. The maximum biomass productivity was 0.26 g/L/d. GP regression analysis revealed that low-level Se treatment could increase the biomass accumulation and the carrying capacity of Chlorella vulgaris K-01 in a heterotrophic culture. The maximum organic Se in biomass was 154.00 μg/g DW. These findings lay the groundwork for understanding heterotrophic microalgal production of Se-containing nutraceuticals, offering valuable insights into Se tolerance, growth dynamics, and metabolic responses in Chlorella vulgaris K-01.

Antitumor efficacy of silver nanoparticles reduced with β-D-glucose as neoadjuvant therapy to prevent tumor relapse in a mouse model of breast cancer

Introduction: Neoadjuvant therapy constitutes a valuable modality for diminishing tumor volume prior to surgical resection. Nonetheless, its application encounters limitations in the context of recurrent tumors, which manifest resistance to conventional treatments. Silver nanoparticles (AgNPs) have emerged as a promising alternative for cancer treatment owing to their cytotoxic effects.Methods: Cellular viability was assessed by Alamar blue assay in 4T1 breast cancer cell line. Silver biodistribution was detected by an inductively coupled plasma optical emission spectrometer in an in vivo mice model. For neoadjuvant evaluation, mice were randomized and treated intratumoral with AgNPs-G or intraperitoneally with doxorubicin (DOX) as a control. Recurrence was determined after 170 days by counting lung metastatic nodules (dyed with Bouin solution) with histological confirmation by H&E. Masson’s stain, Ki67 immunohistochemistry, and a TUNEL assay were performed in lungs from treated mice.Results: AgNPs-G reduced 4T1 cell viability and in an ex vivo assay the AgNPs-G decreased the tumor cell viability. After intravenous administration of AgNPs-G were detected in different organs. After intratumor administration, AgNPs-G are retained. The AgNPs-G treatment significantly reduced tumor volume before its surgical resection. AgNPs-G reduced the development of lung metastatic nodules and the expression of Ki67. TUNEL assay indicated that AgNPs-G didn’t induce apoptosis.Conclusions: We concluded that intratumor administration of AgNPs-G reduced tumor volume before surgical resection, alongside a reduction in lung metastatic nodules, and Ki67 expression. These findings provide valuable insights into the AgNPs-G potential for intratumor and neoadjuvant cancer therapies. However, further research is needed to explore their full potential and optimize their use in clinical settings.

Boosted hydrophobic properties of leather surfaces by atmospheric pressure plasma brush reactor

In this article, we demonstrate the application of an atmospheric pressure plasma brush (APPB) reactor for improving the hydrophobic properties of leather surfaces treated with organo-silane precursors for the first time. A comprehensive investigation was conducted to analyze the influence of various process parameters, including plasma access current, treatment duration, nozzle height, and gas flow rate, on the observed outcomes effects. The dispersion of active particles in the APPB was scrutinized using an Optical Emission Spectrometer (OES), while the underlying reaction mechanism was elucidated through the integration of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), cross-sectional Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM) analysis. The findings unveiled that the resultant polysiloxane polymers bestowed a remarkable degree of hydrophobicity upon the leather, persisting steadfastly even following a 90-day aging period (WCA >140°). This APPB treatment combined with organosilane strategy may open a new design avenue for the development of surface treatments for intricate and temperature-sensitive substrates materials.

Enhancing S45C steel for the primary component of an automatic coupler using quench-tempering techniques

Coupling links and hooked plates constitute the primary components of automatic couplers in trains, enduring substantial tensile and compressive loads during train connections. This study endeavours to enhance the strength of S45C material through heat treatment techniques. The research commenced with the preparation of JIS S45C tensile test specimens adhering to ASTM E8 standards. The material's chemical composition was validated using an Optical Emission Spectrometer (OES). Six heat treatment variations were employed, including quench oil without tempering (QO), quenching water without tempering (QW), quenching oil tempered at 660°C (QOT660), quenching water tempered at 660°C (QWT660), quenching oil tempered at 550°C (QOT550), quenching water tempered at 550°C (QWT550), alongside untreated conditions (NT) for comparison. The efficacy of heat treatment was evaluated through tensile testing, optical metallographic analysis, and micro-Vickers hardness tests. QO and QW scenarios were excluded from the tensile tests. Results revealed that QWT550 demonstrated the most substantial enhancement in material yield, exhibiting a 115% increase. Moreover, hardness testing indicated superior hardness in QWT550 specimens compared to other tempered variants. The metallographic analysis illustrated the formation of identical and smooth martensitic structures. Overall, the combination of cooling heat treatment and tempering proved sufficient to meet the design requirements of hooked plates and coupling links for automatic couplers.

Waterborne metal levels in four freshwater lakes from Harmony Point, Nelson Island, Antarctica.

The aim of this study is to analyze the waterborne metal levels in four lakes (one endorheic and three exorheic) of Harmony Point, Nelson Island, Antarctica. Water samples were analyzed by using a quadrupole type inductively coupled plasma mass spectrometer and an inductively coupled plasma optical emission spectrometer. The levels of As, Cu, Mn, Mo, and V were significantly lower and those of Cr, Mg, Na, and Sr were significantly higher in the endorheic lake than in the other lakes. Most water samples presented levels of Ag, Be, Cd, Pb, Se, Tl, and U below the limit of quantification, while for Ba, Co, and Ni around half of the samples were below this limit. The waterborne metal levels were not significantly different between the exorheic lakes. Waterborne metal levels in the freshwater lakes from Harmony Point did not show any clear relationship with their levels in the soil of the region or with bird guano, and overall, their levels indicate an environment without anthropogenic influence. Apparently, the Na levels are influenced by salt spray from the ocean, as they are related to the distance of the lakes from the ocean.

Synthesis, Characterization of Dy2NdSbO7/Bi2WO6 Heterojunction Photocatalyst and the Application for the Photocatalytic Degradation of Chlorpyrifos under Visible Light Irradiation

A groundbreaking photocatalytic nanomaterial, Dy2NdSbO7, was fabricated smoothly using the hydrothermal synthesis technique for the first time. Apart from that, Dy2NdSbO7/Bi2WO6 heterojunction photocatalyst (DBHP) was initially fabricated using the solvothermal fabrication technique. X-ray diffractometer, Fourier-transform infrared spectrometer, Raman spectrometer, UV-visible spectrophotometer, X-ray photoelectron spectrometer, inductively coupled plasma optical emission spectrometer, transmission electron microscope, and X-ray energy dispersive spectroscopy have been applied to evaluate and investigate the thetastructure, morphology, and physicochemical properties of synthesized samples. The results confirmed that the pyrochlore-type crystal structures of Dy2NdSbO7 belonged to the Fd3m space group with the cubic crystal system and the β-pyrochlore-type crystal structures of Bi2WO6 which belonged to the Pca21 space group with orthorhombic crystal system. Under visible light exposure for 155 min (VLP-155min) using DBHP in the capacity of the photocatalytic nanomaterial, the removal efficiency of chlorpyrifos (CPS) saturation reached 100%. Comparison of CPS removal efficiency after VLP-155min revealed that DBHP exhibited higher removal efficiency than Dy2NdSbO7, Bi2WO6, or N-doped TiO2 photocatalyst, with removal efficiency 1.15 times, 1.23 times, or 2.55 times higher, respectively. Furthermore, the oxidizing capability of free radicals was investigated using trapping agents. Results demonstrated that superoxide anions exhibited the strongest oxidative capability, followed by hydroxyl radicals and holes. The results presented in this study lay a robust groundwork for future investigations and advancements in the field of highly efficient heterostructure material. These findings have significant implications for the development of environmental remediation strategies and provide valuable insights into sustainable solutions for addressing CPS contamination.

Covalent Organic Framework Impregnated with Silver and Copper Nanoparticles: An Advanced Approach for Catalytic Degradation of Organic Pollutants in Wastewater.

In this study, we introduce an economically viable and scalable process for developing a novel covalent organic framework (COF), which is a cross-linked polymer. The resulting material, TzTFB-COF, is successfully functionalized with silver and copper nanoparticles, which show high adequacy in the degradation of nitroaromatic compounds (NACs). For the synthesis of TzTFB-COF, s-tetrazine diamine (Tz) and 1,3,5-triformylbenzene (TFB) are chosen as building blocks, which exhibit a high density of nitrogen-containing sites. TzTFB-COF shows good chemical and thermal stability (>300 °C). For functionalization of TzTFB-COF with silver and copper nanoparticles, a solution infiltration technique is used. The composite materials, i.e., Ag@TzTFB-COF and Cu@TzTFB-COF, have been characterized using various spectroscopic and analytical techniques, which show high activity, high selectivity, and excellent chemical and thermal stability up to 350 °C. The silver and copper contents of Ag@TzTFB-COF and Cu@TzTFB-COF are determined to be 9.6 and 12.4 wt % by inductively coupled plasma optical emission spectrometer (ICP-OES). The catalytic efficiency of the synthesized Ag@TzTFB-COF and Cu@TzTFB-COF materials is assessed in the context of catalyzing the hydrogenation of NACs. Experimental results reveal a remarkable catalytic performance when conducted in an aqueous medium, and notably, the materials demonstrate substantial potential for reusability across multiple catalytic cycles. The determined parameters for the catalytic hydrogenation reaction, i.e., the rate constants and Gibbs free energies, are found to be 0.0185 s-1 and 9.878 kJ/mol for Ag@TzTFB-COF and 0.0219 s-1 and 9.615 kJ/mol for Cu@TzTFB-COF. Thus, the catalytic reaction exhibits characteristics of endothermic, endergonic, and nonspontaneous nature.

Influence Mechanism of Water Content and Compaction Degree on Shear Strength of Red Clay with High Liquid Limit.

To investigate the influencing factors and mechanisms of shear strength of red clay with a high liquid limit, which was selected at different milepost locations based on the Nanning Bobai Nabu Section Project of the Nanning Zhanjiang Expressway, the basic physical properties of red clay were determined using a liquid plastic limit test, compaction test, inductively coupled plasma optical emission spectrometer (ICP-OES), and X-ray fully automatic diffractometer (XRD). Red clay with a high liquid limit was selected. Furthermore, the direct shear test was used to study the effect of different water contents and compaction degrees on the shear strength. The experimental results demonstrate that under the same compaction degree, the shear stress of the soil sample increases significantly with an increase in normal stress, and the greater the water content, the smaller the shear stress of the soil sample. At 200 kPa, the shear strength of soil samples with 24% water content is 57%, 46%, and 35% of the shear strength of soil samples with 15% water content under different compaction degrees(K) of 86%, 90%, and 93%, respectively. Under the same moisture content, the shear stress of the soil sample shows an increasing trend with an increase in the degree of compaction, and the greater the compaction degrees, the greater the shear stress of the soil sample. The cohesion c and internal friction angle φ of soil samples increase with an increase in the compaction degree, but the increase in cohesion c is also affected by the water content. Under the condition of low water content, the cohesion c of soil samples can be increased by 1.06 times when the water content is 15% and by 0.47 times when the water content is 18%. Under the condition of high water content, the cohesion c of soil samples with 21% water content only increases by 0.3 times, and that with 24% water content only increases by 0.35 times.

Improved Soil Amendment by Integrating Metal Complexes and Biodegradable Complexing Agents in Superabsorbents.

The superabsorbents' application as materials for the preparation of modern mineral fertilizers of controlled activity is presented. Under the static conditions, the commercial acrylic-based Agro® Hydrogel was used as a sorbent for Cu(II), Fe(III), Mn(II), and Zn(II) ions in the presence of three biodegradable complexing agents of the new generation: (N-1,2-dicarboxyethyl)-D,L-aspartate acid (IDHA), N,N-ethylenediaminedisuccinic acid (EDDS) and N,N-bis(carboxymethyl) glutamic acid (GLDA). The ions and complexes concentrations were determined by the inductively coupled plasma optical emission spectrometer (ICP-OES). The characterization of hydrogel before and after the adsorption process was made using the Fourier transform infrared spectroscopy (FT-IR), surface area determination (ASAP), scanning electron microscopy (SEM-EDS) as well as the thermogravimetric (TGA) methods. The influence of the phase contact time, initial concentration, and pH on the adsorption capacities was investigated. The kinetic and adsorption parameters were determined. The Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin adsorption models were applied to describe the experimental data. The Langmuir isotherm model accurately characterized the equilibrium process. The adsorption process was fast, and it reached equilibrium after 60 min of the phase contact time. The research on the adsorption of Cu(II), Fe(III), Mn(II), and Zn(II) onto Agro® Hydrogel with IDHA, EDDS, and GLDA indicates that these complexing agents improve process efficiency.

Comparison of plasma electrolytic oxidation coatings on Al alloy produced in diluted and concentrated silicate electrolytes for space thermal control application

In this work, a bright white oxide coating was successfully prepared on 6061 Al alloy by PEO process from an environmentally friendly and low-cost concentrated silicate electrolyte as an alternative for commonly used fluozirconate electrolyte. The characteristics of PEO processes and resulting coatings both in diluted and concentrated silicate electrolytes were investigated by using Optical Emission Spectrometer (OES), Scanning Electron Microscope (SEM), X-ray Energy Dispersive Spectrometer (EDS) and X-ray Diffraction Spectrometer (XRD). The thermal control properties of the coatings were evaluated by UV-VIS-NIR spectrophotometer and infrared emissivity spectrometer, respectively. The corrosion protection performances of the coatings were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. Results show that the discharges in diluted silicate electrolyte are more pronounced than those in concentrated silicate electrolyte. The more intensive discharges in diluted silicate electrolyte are related to plasma electrochemical reactions at the material surface or at the metal-oxide interface, facilitating to a relatively dense structure and complex oxides including α-Al2O3, γ-Al2O3 and mullite. The weaker discharges in concentrated silicate are associated with the fast silicate anions deposition process, resulting in the formation of amorphous SiO2 with a porous microstructure and high thickness. The coating prepared in concentrated silicate electrolyte is characterized by a bright white color in appearance and has much lower solar absorptance (αs) of 0.159 and higher emissivity (ε) of 0.90 than the coating prepared in diluted silicate electrolyte with αs of 0.429 and ε of 0.79. However, the coating prepared in concentrated silicate electrolyte has a little inferior corrosion protection performance compared with that prepared in diluted silicate electrolyte due to the more porous microstructure.

Interaction of Heavy Metals with Plastic Contaminated Soil

Microplastic (MP) contamination is a threat to soil and groundwater system. Disintegration of used plastic products under exposure to solar radiations, application of sewage sludge to the soil, plastic mulching in agricultural activities leads to the formation of microplastics in significant amounts in soil. Hence there is a need from the geo environment engineering perspective on microplastic contamination in soils. Landfills and industrial areas have microplastic pollution in abundance. The presence of microplastic may alter the behaviour of liner material and surface soil in terms of heavy metal retention capacity, shrinkage, permeability and various other properties. In the present study, the soil is artificially polluted with shredded polypropylene (Pp) fragments from single use facial mask which is extensively being used in post COVID-19 situation. Heavy metals such as Lead, Nickel, Copper and Zinc at different concentrations similar to an industrially polluted soil is applied to the plastic contaminated (Pc) and normal soil. The filtrates from the test batches are studied for Total Dissolved Solids (TDS) and concentration of heavy metals using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The obtained results concluded that plastic pollution significantly varied leached out heavy metals concentration to a maximum of 4.9 times that of normal soil. The TDS of the filtrate collected from plastic polluted soil varied by 31.29%.

Гигиеническая характеристика загрязнения воздуха рабочей зоны сварочного производства в судостроении (на примере верфей Санкт-Петербурга)

Laboratory tests of air pollution at shipbuilding enterprises have shown that dust particles of welding aerosol consist of both poorly soluble Al, Fe, Ti and Pb compounds and Co, Cr, Cu, Mn and V compounds that are highly soluble in an artificial solution, while their ratio varies depending on the welding method. The purpose of this article was to perform a hygiene assessment of the air pollution in the shipyards’ working areas, taking into account solubility test results for the metal compounds contained in the welding aerosol. Materials and methods. The object of the study were the welding processes of two shipyards in St. Petersburg, Russia. We collected 97 air samples from under the welder’s face shield using 5.0 µm membrane filters and SKC Sidekick personal pumps. The soluble and insoluble chemical compounds of the welding aerosol in the artificial solution were analysed using an inductively coupled plasma mass spectrometer (Thermo Scientific Element XR) and an inductively coupled plasma optical emission spectrometer (Perkin Elmer Optima 7300V). Results. Significant differences were established between the enterprises in the shift-weighted average concentrations of chemicals in the air of welding areas: by the factor of 19.6 for manganese (181.04 and 3563.80 µg/m3) and 1.5 for iron (1291.71 and 862.49 µg/m3). We recorded a wide range of shift-weighted average concentrations of welding aerosols with a complex chemical composition in the welding working areas. However, there were significant hygienic differences in the test results between the shipyards. One of the important characteristics of welding aerosol studied here is the solubility of its elements, which determines the ability of toxic substances to penetrate through the lung tissue into the bloodstream, causing acute or chronic health effects. Thus, hygiene assessments of the air pollution in the working areas in shipbuilding should be based on a personalized approach and take into account changes in the welding methods applied, types of welding materials, etc.

Flame‐retardant epoxy resin with good smoke‐suppression endowed by chitosan–cobalt/phosphorus complex

AbstractChitosan‐based flame‐retardant CS–Co–DOPA (CCD) was synthesized by the neutralization reaction of 10‐hydroxy‐9,10‐dihydro‐9‐oxo‐10‐phosphaphenanthrene‐10‐oxide (DOPA) with chitosan‐cobalt complex and fully characterized by scanning electron microscopy (SEM), energy‐dispersive spectrometer, x‐ray diffraction, X‐ray photoelectron spectroscopy (XPS), optical emission spectrometer, and Fourier transform infrared (FTIR) characterizations. The epoxy resin (EP) modified with CCD exhibited good flame retardancy. With the addition of 5 wt% CCD, the EP/CCD achieved UL‐94 V‐1 rating and possessed limiting oxygen index (LOI) value of 30%. Cone calorimetry (CC) test demonstrated that EP/CCD resulted in a remarkable reduction of peak smoke production rate (pSPR) and total smoke production (TSP) by 63% and 40%, respectively, showing an outstanding smoke suppression. The char residue obtained from the CC test was further characterized using SEM, FTIR, Raman, and XPS techniques. The results revealed that CCD facilitated the formation of a dense and compact char layer on EP during combustion, thereby impeding gas and heat transfer. In addition, TG‐IR was employed to investigate the gas‐phase flame‐retardant effect of EP/CCD composites, which revealed that CCD promotes the release of water, CO2, and other incombustible gases, altering the decomposition path of EP.

Influence of gender and combined estrogen-progestin oral contraceptive on parotid saliva flow rate, pH, and electrolytes concentration.

Endocrinal variations within an individual impact the electrolyte composition, pH, and flow-rate (FR) of saliva. The aim of this study was to evaluate the gender-specific differences and the effect of combined estrogen-progestinoral contraceptives(COCs) on FR, pH, and electrolyte concentrations in the parotid saliva (PS) of a group of healthy adults. Stimulated PS was collected from 20 healthy adults using a Lashley cup; 11 males, 8 females, and 1 female undertaking combined contraceptive therapy (levonorgestrel/ethinyloestradiol 0.1 mg + 0.02 mg). FR and pH were recorded for each saliva sample. Electrolytes concentrations (Na+ , Ca2+ , K+ , Mg2+ ) were measured using inductively coupled plasma optical emission spectrometer (ICP-OES). Statistical analysis was performed, and the significance level was set at p < .05. PS FR varied from 0.13 to 0.42 mL/min in females not taking any medication and from 0.08 to 0.5 mL/min in males not taking any medication. PS pH of females and males not taking any medication ranged from 6.23 to 7.50 and from 6.15 to 7.55. PS pH and FR of the female taking COCs were 6.5 and 0.1 mL/min. PS pH, FR, and electrolytes concentrations (Ca2+ , Na+ , K+ , Mg2+ ) were not statistically significantly different between females and males not taking any medication. PS concentrations of Ca2+ and Na+ were significantly higher in the females taking COCs than in the females not taking any medication. Whereas, concentrations of K+ and Mg2+ did not differ significantly between the females taking COCs and the females not taking any medication. There are no significant gender-specific differences in PS flow rate, pH, and electrolyteconcentrations of Na+ , Ca2+ , Mg2+ , and K+ . Combined hormonal oral contraceptive has a significant effect on PS flow rate, pH, Ca2+ , and Na+ concentrations. Whereas the PS concentration of K+ and Mg2+ are not influenced by COCs. These results warrant further investigation.