Concentrations Of Metal Elements Research Articles

CONTRIBUTION TO THE STUDY OF THE PHYSICO-CHEMICAL QUALITY OF THE SURFACE WATER OF THE RIVER SEYBOUSE

Like all parts of the North- east Algeria, the study area has considerable surface water wealth, to which attention must be reserved. River Seybouse, which is fed by a network of rivers, is one of the most important rivers of this region; it drains the Guelma basin towards West-East clearly on nearly 45 km with a total contribution estimated at 408 Hm3/ year to Boudraoua station (Bouchegouf). In parallel with the rapid population growth, record the development of agricultural and industrial sectors that knows the study area in recent decades, River Seybouse, became the seat of important illegal dumping and polluting discharges. For this purpose, samples of water samples were conducted at nine stations during wet periods and dry periods. A multidisciplinary analysis concerned in particular, the physicochemical parameters (T°, pH, CE, O<sub<2</sub<, Cl<sup<-</sup<, PO<sub<4</sub<, NO<sub<2</sub< and NO<sub<3</sub<), the evaluation of contamination by trace elements (Fe, Mn, Cu, Zn). The analysis results show that the waters of this river are characterized by high natural mineralization and concentrations substantially higher than the standards recommended by OMS and Algerian standards of the various parameters reflecting generally the waters of this course of water are of good quality. The concentrations of metallic elements are not alarming, and the degree of metal contamination differs from one site to another depending on the distance away from the source of pollution.

Conversion of waste non-chrome metal complex tanned leather shavings to dual-functional bio-additive for the high-performance biomass-derived aldehyde tanned leather processing

Waste collagen fiber (WCF) from non-chrome metal complex tanned leather shavings were converted to bio-additive (DCH) via catalytic peroxide oxidation for updating the performance of biomass-derived aldehyde (BAT) tanned chrome-free leather. The conversion degree of WCF was investigated, and four typical DCHs with different molecular weights (DCH-1: 19695 g/mol; DCH-2: 14942 g/mol; DCH-3: 8222 g/mol; DCH-4: 2959 g/mol), were selected for the post-tanning of BAT tanned leather. ICP-OES analysis indicated that DCH had similar metallic element content. FTIR showed that more carboxyl groups of DCH were formed as the decrease of its molecular weight (MW) due to the cleavage of peptide chains and de-tanning reaction, which was further verified by the decrease of isoelectric point (IEP) of DCH. During the post-tanning process, DCH had no obvious negative impacts on the overall uptake of post-tanning materials and the shrinkage temperature of leather, but it could perform a feasible filling effect. Besides, DCH could endow the crust leather with better dyeing uniformity, mechanical strengths, and organoleptic properties than commercial protein filler due to its special structure containing multivalent metal ions. This suggests that the as-prepared DCH has the capability for manufacturing high-performance chrome-free leather tanned by BAT.

Trace Element and Isotope Systematics in Vent Fluids and Sulphides From Maka Volcano, North Eastern Lau Spreading Centre: Insights Into Three-Component Fluid Mixing

Back-arc spreading centres and related volcanic structures are known for their intense hydrothermal activity. The axial volcanic edifice of Maka at the North Eastern Lau Spreading Centre is such an example, where fluids of distinct composition are emitted at the Maka hydrothermal field (HF) and at Maka South in 1,525–1,543 m water depth. At Maka HF black smoker-type fluids are actively discharged at temperatures of 329°C and are characterized by low pH values (2.79–3.03) and a depletion in Mg (5.5 mmol/kg) and SO4 (0.5 mmol/L) relative to seawater. High metal (e.g., Fe up to ∼6 mmol/kg) and rare Earth element (REE) contents in the fluids, are indicative for a rock-buffered hydrothermal system at low water/rock ratios (2–3). At Maka South, venting of white smoke with temperatures up to 301°C occurs at chimneys and flanges. Measured pH values range from 4.53 to 5.42 and Mg (31.0 mmol/kg), SO4 (8.2 mmol/L), Cl (309 mmol/kg), Br (0.50 mmol/kg) and Na (230 mmol/kg) are depleted compared to seawater, whereas metals like Li and Mn are typically enriched together with H2S. We propose a three-component mixing model with respect to the fluid composition at Maka South including seawater, a boiling-induced low-Cl vapour and a black smoker-type fluid similar to that of Maka HF, which is also preserved by the trace element signature of hydrothermal pyrite. At Maka South, high As/Co (>10–100) and Sb/Pb (>0.1) in pyrite are suggested to be related to a boiling-induced element fractionation between vapour (As, Sb) and liquid (Co, Pb). By contrast, lower As/Co (<100) and a tendency to higher Co/Ni values in pyrite from Maka HF likely reflect the black smoker-type fluid. The Se/Ge ratio in pyrite provides evidence for fluid-seawater mixing, where lower values (<10) are the result of a seawater contribution at the seafloor or during fluid upflow. Sulphur and Pb isotopes in hydrothermal sulphides indicate a common metal (loid) source at the two vent sites by host rock leaching in the reaction zone, as also reflected by the REE patterns in the vent fluids.

Preliminary studies of Volten VR4® Kaempferia parviflora herb extracts on blood glucose levels in human type-2 diabetes mellitus and its mineral element analysis

Summary Introduction Volten VR4® capsules containing herb extract of Kaempferia parviflora has been claimed to reduce blood glucose in patients with diabetes. Objectives This preliminary study is conducted to evaluate the efficacy of Volten VR4® on healthy individuals and type-2 diabetes mellitus volunteers. The extracts of 400 mg capsules of Kaempferia parviflora (KP) were used to measure the blood glucose level of 2-hour postprandial. Methods The healthy group consists of 15 young adults aged 20-30 with no history of serious diseases, while the diabetic group includes 12 individuals aged 35-75 diagnosed with type-2 diabetes mellitus. Data were validated through the Willcoxon and Friedman test statistics and error distribution. The investigation was continued to trace the capsules contents of elements using inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. Results It has been shown that KP reducing blood sugar levels has been associated with flavonoids and methoxyflavones components. The result specifically showed that consuming VR4® capsules can significantly reduce blood glucose, either at the state of fasting or postprandially. In the study the content of mineral and heavy metal elements in VR4® capsules has been evaluated. Conclusion Volten VR4® Kaempferia parviflora extract is safe to be consumed at a single dose of 400 mg. The study also has shown that the participants are free from adverse reactions and hypoglycaemia.

Spatial Distribution Characteristics and Risk Assessment of Nutrient Elements and Heavy Metals in the Ganjiang River Basin

The pollution of water bodies by nutrients and heavy metals can lead to a loss of biodiversity, environmental degradation, and harm to human health. During the two-month monitoring period (e.g., December 2019 to January 2020), variables such as trace metals (e.g., Cu, Zn, As, and Cr), nutrients (e.g., NH4+-N, TN, and TP), water temperature, pH value, dissolved oxygen (DO), chemical oxygen demand (COD) and five-day biochemical oxygen demand (BOD5) were measured at 102 monitoring points in the main stream and tributaries of the Ganjiang River in the Poyang Lake Basin. A variety of multivariate statistical techniques, including cluster analysis (CA), principal component analysis (PCA), and correlation analysis, were used to conduct risk assessments and source analyses of the nutrient elements and heavy metals in the Ganjiang River system. The results show that although the Ganjiang River Basin is polluted by human activities, its water chemistry characteristics and trace metal and nutrient elements concentrations were better than the national standards. Through principal component analysis, the water pollution sources could be divided into urban sewage, agricultural activities, industrial activities, and the sources of industrial activities and transportation activities. The comprehensive risks of noncarcinogens (Hc) and comprehensive risks of carcinogens (Rc) for adults and children due to drinking water indicated that the risk from drinking water for the children in the basin was greater than that for adults, and that the Hc for adults and children was acceptable. However, the Rc for adults and children was slightly higher than the acceptable values. This study provides a reference for the fine control of the environmental water pollution sources in the Ganjiang river basin and health risk assessments in the basin, which are of great significance for improving the environmental water quality standards in the river basin and for reducing the risk of carcinogenesis.

Human Activity in Antarctica: Effects on Metallic Trace Elements (MTEs) in Plants and Soils.

Colobanthus quitensis (Kunt) is one of the two vascular plant species present in Antarctica and develops under severe environmental conditions, being found in both pristine and human-threatened environments. We determined the Cd, Cr, Cu, Mn, Ni, Pb, and Zn levels in C. quitensis roots, leaves, and soils of origin using flame atomic absorption spectroscopy. In January 2017, we collected samples from four geographical zones on the longitudinal gradient along which C. quitensis is distributed, starting from Punta Arenas (PAR) at the extreme south of mainland Chile and moving southwards to the Antarctic territory from King George Island (KGI) to Hannah Point Peninsula (PHA) and finally Lagotellerie Island (LAT). We used certified reference material to validate the plant tissues and soil samples we collected. The highest concentrations of metals that we measured in the soils and in the C. quitensis roots and leaves were in samples we collected at the KGI station, the zone with the greatest human activity. The lowest concentrations we measured were at the LAT station, an island with little human intervention and scarce fauna. The mean concentrations of metals in the roots and leaves of C. quitensis followed a similar order at all sampling locations: Mn > Zn > Cu > Ni > Pb > Cr > Cd. In contrast, in soil, they followed the following order: Mn > Zn > Cu > Cr > Pb > Ni > Cd. The concentration levels obtained for the different metals in the soil and plants tissue samples in this region of Antarctica indicated that the area was non-polluted. However, the metallic trace element (MTE) concentrations may be at an early stage of contamination, as described in other areas of the Antarctic, being a new threat to this continent.

A metabolome-wide association study of in utero metal and trace element exposures with cord blood metabolome profile: Findings from the Boston Birth Cohort

BackgroundExposure to metals lead (Pb), mercury (Hg), and cadmium (Cd) and trace elements selenium (Se) and manganese (Mn) has been linked to the developmental origins of cardiometabolic diseases, but the mechanisms are not well-understood. ObjectiveConduct a metabolome-wide association study to understand how in utero exposure to Pb, Hg, Cd, Se, and Mn affects the metabolic programming of fetuses. MethodsWe used data from the Boston Birth Cohort, which enrolled mother-child pairs from Boston, MA. We measured metals and trace elements in maternal red blood cells (RBCs) collected 24–72 h after delivery, and metabolites in cord blood collected at birth. We used multivariable linear regression to examine associations of metals and trace elements with metabolites and Bonferroni correction to account for multiple comparisons. We assessed non-linear associations of metals and trace elements with metabolites using restricted cubic spline plots. ResultsThis analysis included 670 mother-child pairs (57% non-Hispanic Black and 24% Hispanic). After Bonferroni correction, there were 25 cord metabolites associated with at least one of the metals or trace elements. Pb was negatively associated with the xenobiotic piperine, Cd was positively associated with xenobiotics cotinine and hydroxycotinine, and Hg was associated with 8 lipid metabolites (in both directions). Se and Mn shared associations with 6 metabolites (in both directions), which mostly included nucleotides and amino acids; Se was additionally associated with 7 metabolites (mostly amino acids, nucleotides, and carnitines) and Mn was additionally associated with C36:4 hydroxy phosphatidylcholine. Restricted cubic spline plots showed that most associations were linear. DiscussionMaternal RBC metal and trace element concentrations were associated in a dose-dependent fashion with cord blood metabolites. What remains to be determined is whether these metals- and trace elements-associated changes in cord metabolites can influence a child’s risk of cardiometabolic diseases.

Variations of some Metallic Elements in Different Parts of Lingonberries (Vaccinium vitis-idaea L.)

The aim of the research was to evaluate the content of metallic elements in different parts of lingonberries (Vaccinium vitis-idaea L.) depending on their place of growth and evaluate the transfer factor values from between different parts of plants (fine roots, leaves, berries). Obtained results show that there are no significant differences between the content of Fe, Cu, Zn and K, and there are similar element transfer factors between different parts of lingonberries independent from which site the samples are taken.

Properties of Spark Plasma Sintered Compacts and Magnetron Sputtered Coatings Made from Cr, Mo, Re and Zr Alloyed Tungsten Diboride

To enhance the properties of tungsten diboride, we have synthesized and characterized solid solutions of this material with chromium, molybdenum, rhenium and zirconium. The obtained materials were subsequently deposited as coatings. Various concentrations of these transition metal elements, ranging from 0.0 to 24.0 at.%, on a metals basis, were made. Spark plasma sintering was used to synthesize these refractory compounds from the pure elements. Elemental and phase purity of both samples (sintered compacts and coatings) were examined using energy dispersive X-ray spectroscopy and X-ray diffraction. Microindentation was utilized to measure the Vickers hardness. X-ray diffraction results indicate that the solubility limit is below 8 at.% for Mo, Re and Zr and below 16 at.% for Cr. Above this limit both diborides (W,TM)B2 are created. Addition of transition metals caused decrease of density and increase of hardness and electrical conductivity of sintered compacts. Deposited coatings W1−xTMxBy (TM = Cr, Mo, Re, Zr; x = 0.2; y = 1.7–2) are homogenous, smooth and hard. The maximal hardness was measured for W-Cr-B films and under the load of 10 g was 50.4 ± 4.7 GPa. Deposited films possess relatively high fracture toughness and for WB2 coatings alloyed with zirconium it is K1c = 2.11 MPa m1/2.

Security Risk and Influencing Factors of Agro-Products in Farmland Soil Around a Typical Mining Smelter

The security risks of heavy metal pollution in agro-products are becoming increasingly serious. This paper investigated the heavy metal contamination of farmland soils and agro-products around a typical mining smelter in Hunan province, and explored the influencing factors based on principal component and correlation analyses. The results showed that the soils were significantly contaminated by heavy metals, with a mean concentrations of Cd, Cu, Pb, and Zn of 9.12, 358, 303, and 185 mg·kg-1, respectively, pH range from 4.67 to 7.22. All the sites included were under strict control. With regards to the agro-products, the concentration of heavy metal elements were different, and the order of heavy metal concentrations was Zn>Cu>Pb>Cd, with an order of biological enrichment factor(BCF) of Cd>Zn>Cu>Pb. Over-the-standard elements in agro-products included Pb and Cd at 78% and 41%, respectively, which indicated a higher security risk from these products. The accumulation of the same heavy metals in leaf vegetables were generally higher than sweet potatoes and solanaceous vegetables. The heavy metal concentrations in soils corresponded to the first principal component(P<0.01), with the variance reaching 88.0%, which dominated the sources of Cd, Cu, Pb, and Zn in agro-products. The enrichment characteristics were mainly affected by the type of crops, and was also regulated by the soil pH, cation exchange capacity, and soil organic matter(the correlation coefficients of r were -0.407- -0.641, P<0.05). In conclusion, there was a combined heavy metal pollution and high risk in soils and agro-products. Therefore, the planting of crops in the study area should be avoided, and soil remediation measures should be implemented to reduce security risks.

Study of Alteration Geochemistry and Mineralization in the Jawara Field, Jember Regency, East Java Province

The Jawara Field in Jember Regency is a location where it is indicated that there are precious metal deposits in the form of porphyry type Gold and Copper. In this study, the focus is more on the search for metal mineral deposits related to the elements of Gold (Au) and Copper (Cu), namely the metal mineral chalcopyrite (CuFeS2) as the main carrier minerals for Au, Cu, Ag, as impurities. The results of alteration products in the form of weathered minerals are also the focus of research. The analysis used to detect metallic element content and the presence of metallic and non-metallic minerals is by petrographic analysis, mineragraphy analysis, sediment grain analysis and geochemical analysis. Based on the results of the mineragraphy analysis, it was proven that the metal mineral chalcopyrite was found in the JAFA 6 BPS sample which is a carrier mineral for the metallic copper element and silver was also found in JAFA 2 ALT. In addition, the results of the sediment grain analysis also found metal mineral grains and metal elements, namely copper and iron elements in all JAFA samples. The results of petrographic analysis show that the weathered minerals in the form of kaolinite, alunite, and smectite are products of hydrothermal alteration activities. Based on these results, the research area is divided into 3 alteration zones, namely potassic, propylitic, and argillic alteration zones. The results of the geochemical analysis showed that the highest levels of copper were found in JAFA 5 as much as 13.9 ppm and the highest levels of iron in JAFA 6 were 390.8 ppm. From the results of the analysis, it can be concluded that it is true that there are metal mineral deposits and metal elements in the form of sediment grains and porphyry-type Au and Cu elements.

Nutritional Quality of the Most Consumed Varieties of Raw and Cooked Rice in Spain Submitted to an In Vitro Digestion Model

Rice is one of the most consumed staple foods around the world and its trade is highly globalized. Increased environmental pollution generates a large amount of waste that, in many cases, is discarded close to culture fields. Some species are able to bioaccumulate toxic substances, such as metals, that could be transferred to the food chain. The main goal of this study was to evaluate the content of metallic (Al, Cd, Pb, and Cr) and metalloid elements (As) in 14 of the most consumed varieties of rice in Spain and their effects on human health. The samples were cooked, and human digestion was simulated by using a standard in vitro digestion method. Metallic and metalloid element levels were analysed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), previous called microwave digestion. Both the human health risk index, Hazard Quotient, and Lifetime Cancer Risk did not show toxic values in any case. Rice with a higher non-digestible fraction showed a higher liberation of proteins and a lower glycemic index. There were no significant differences in the concentrations of metallic and metalloid elements in cooked rice or in the digestible fraction in all varieties analysed. However, Al concentrations were higher than other metals in all varieties studied due to its global distribution. No relationship has been observed between the digestibility of rice and the bioaccessibility of each metallic and metalloid element. All of the studied rice varieties are healthy food products and its daily consumption is safe. The regular monitoring of metals and As in rice consumed in Spain may contribute to improvements in the human health risk evaluation.

Trace elements (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in Mytilus galloprovincialis and Tapes decussatus from Faro and Ganzirri Lakes (Sicily, Italy): Flow cytometry applied for hemocytes analysis

BackgroundTrace elements present in sessile molluscs, are important because they are used in human consumption and it has significantly increased in recent years. While their filtering of the water can lead to their build-up of organic and inorganic materials that can be sampled and analyzed, this can also lead to bioaccumulation of harmful substances, such as essential and non-essential elements, that can harm the human health if in taken in high concentrations or for a long period of time. MethodsIn the present study, the trace metal content (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of two sessile crustaceans, 20 Mytilus galloprovincialis (mussel) and 20 Tapes decussatus (clam) in Faro and Ganzirri Lakes (Messina, Sicily, Italy) were analyzed. Haemolymph samples were taken on both molluscs in order to analyze the haemocyte population by flow cytometric analysis. Unpaired t-tests were used to determine significant differences for the essential and non-essential metallic elements concentrations in the lake waters and in the tissues of M. galloprovincialis and T. decussatus and for hemocyte populations R1 (halinocytes) and R2 (granulocytes). ResultsThe results suggested that that in Faro Lake, the tissue Al, Cr and Pb levels in M. galloprovincialis were higher than those for T. decussatus, in contrast to Mn, Fe, Ni, Cu, Zn and Cd, which were higher in T. decussatus. Unpaired t-tests showed that there were significantly higher proportions of halinocytes in M. galloprovincialis versus T. decussatus for both Faro Lake (41.8 % vs. 24.3 %; P < 0.001) and Ganzirri Lake (43.0 % vs. 22.4 %; P < 0.001). In contrast, while there were significantly higher proportions of granulocytes in Faro Lake (21.2 % vs. 9.1 %; P < 0.001), this difference was not seen for the granulocytes of M. galloprovincialis versus T. decussatus in Ganzirri Lake (9.6 % vs. 13.0 %). ConclusionThis study shows that M. galloprovincialis and T. decussatus can indeed bioaccumulate some of these metal, such that activation of the immune responses is specific to certain cell types. Future research must focus on the balance of trace elements in the consumption of these shellfish, and analyzes with more sophisticated tools can be used to diagnose the increased concentration of trace elements and the quantification of trace metals from shellfish to clams.

Association between the Concentrations of Metallic Elements in Maternal Blood during Pregnancy and Prevalence of Abdominal Congenital Malformations: The Japan Environment and Children's Study.

Abdominal congenital malformations are responsible for early mortality, inadequate nutrient intake, and infant biological dysfunction. Exposure to metallic elements in utero is reported to be toxic and negatively impacts ontogeny. However, no prior study has sufficiently evaluated the effects of exposure to metallic elements in utero on abdominal congenital malformations. The aim of the present study was to evaluate associations between metallic elements detected in maternal blood during pregnancy and congenital abdominal malformations. Data from participants in the Japan Environment and Children’s Study was used in the present study, and contained information on singleton and live birth infants without congenital abnormalities (control: n = 89,134) and abdominal malformations (case: n = 139). Heavy metals such as mercury (Hg), lead (Pb), cadmium (Cd), and trace elements of manganese (Mn) and selenium (Se) were detected in maternal serum samples during mid- and late-gestation. Infant congenital abnormalities were identified from delivery records at birth or one month after birth by medical doctors. In a multivariate analysis adjusted to account for potential confounders, quartiles of heavy metals and trace elements present in maternal blood were not statistically correlated to the prevalence of abdominal congenital malformations at birth. This study is the first to reveal the absence of significant associations between exposure levels to maternal heavy metals and trace elements in utero and the prevalence of abdominal congenital malformations in a large cohort of the Japanese population. Further studies are necessary to investigate the impact of exposure to heavy metals and trace elements via maternal blood in offspring after birth.

Evaluation of various microwave-assisted acid digestion procedures for the determination of major and heavy metal elements in municipal solid waste incineration fly ash

Municipal solid waste incineration (MSWI) generates large amounts of fly ash, which requires proper disposal due to containing high levels of toxic elements. Accurate determination of the contents of these elements is crucial to its further treatment and utilization. Microwave-assisted acid digestion is a widely used approach for elemental determination in MSWI fly ash. The digestion procedure affects the analytical results of element contents. This study compares various procedures for microwave-assisted acid digestion of MSWI fly ash in the literature and standard methods. Factors including four common acid combinations and sample mass (from 25 to 250 mg) were investigated, and the analytical results for major and heavy metal element contents were evaluated. The effects of HF and HClO4 in acid combinations were studied in detail. The results showed that acid combinations and sample mass significantly affect analytical results for Ca, Mg, Al, Ba, and Sr. HF is essential to the total digestion of MSWI fly ash, but can lead to loss of Ca, Mg, Al, Ba, and Sr. Loss of elements was caused by the precipitation of Ca and HF as well as complex co-precipitation reactions during digestion. Reducing sample mass and using HClO4 can mitigate loss of element and facilitate the determination of elements in MSWI fly ash.

Contamination characteristics, mass concentration, and source analysis of metal elements in PM2.5 in Lanzhou, China

PM2.5 and its bound metals pose a serious threat to human health. Understanding their contamination characteristics and source could provide implication for controlling their spreading and ensuring air quality. In this article, 1,600 of PM2.5 samples were collected from 5 urban sites in Lanzhou, China. The contamination characteristics of PM2.5, its relationship with meteorological factors, and the source of its bound metals were studied based on multiple linear regression analysis, enrichment factor (EF), principal component analysis and correlation analysis. The outcomes show that the PM2.5 concentrations in winter (0.117 mg·m–3) and spring (0.083 mg·m–3) are higher than those in summer (0.043 mg·m–3) and autumn (0.048 mg·m–3). The influence degree of meteorological factors on PM2.5 concentration is in the order of wind speed &amp;gt; atmospheric pressure &amp;gt; temperature &amp;gt; humidity. The major source of Fe and Cu in PM2.5 is construction dust, Pb and As is industrial, and Hg is coal combustion. In addition, Cd, V, Co, and Mn are mainly derived from dust produced by weathering of soil or rock. In general, the spatiotemporal distribution of PM2.5 and its bound metals are different, which is closely related to geographical location, source, and meteorological factors. The results in this article could provide support for the scientific formulation to prevent air pollution in Lanzhou.

Characterization of PM-Bound Heavy Metal at Road Environment in Tianjin: Size Distribution and Source Identification

To determine the size distribution and source identification of PM-bound heavy metals in roadside environments, four different particle size (&lt;0.2 μm, 0.2–0.5 μm, 0.5–1.0 μm and 1.0–2.5 μm) samples were collected and analyzed from four different types of roads during the summer of 2015 in Tianjin. The results showed that the concentrations of PM-bound heavy metal from the roadside environment sampling sites were 597 ± 251 ng/m3 (BD), 546 ± 316 ng/m3 (FK), 518 ± 310 ng/m3 (JY) and 640 ± 237 ng/m3 (WH). There were differences in the concentrations of the heavy metal elements in the four different particle size fractions. The concentrations of Cu, Zn, Cd, Sn and Pb were the highest in the larger particle size fraction (0.5–2.5 μm). Cd, Cu, Zn and Pb were the elements that indicated emissions from tire wear and brake pad wear. The concentrations of Cr, Co and Ni were the highest in the smallest particle size fraction (&lt;0.5 μm), indicating that motor vehicle exhaust was their main source. The correlation analysis results showed that there are differences in the concentration, distribution and correlation of different PM-bound heavy metals in different particle size fractions. The PCA results show that the accumulative interpretation variances of PM0.2, PM0.2–0.5, PM0.5–1.0 and PM1.0–2.5 reached 80.29%, 79.56%, 79.57% and 71.42%, respectively. Vehicle exhaust was the primary source of PM-bound heavy metal collected from the roadside sampling sites, while brake pad wear and tire wear were the second most common sources of the heavy metal.

Application of Energy Dispersive X-ray Fluorescence Analysis in the detection of heavy metal element content

The method of food safety testing is usually to use different testing methods to determine the various elements contained in the food to obtain whether its content meets human health standards compared with international standards. At the same time, it can be judged its origin by the content of elements detected in the food, and analyze the impact of environment pollution on its growth. Commonly used methods for detecting heavy metals in food include ICP-AES/MS, flame atomic absorption method, graphite furnace atomic absorption spectrometry and so on. The introduction of physical rapid detection methods into the field of food safety detection can greatly reduce the time required for food detection. Among them, EDXRF is a non-destructive analysis method, which can simplify the analysis process while achieving detection accuracy, and does not require chemical steps to make it more than traditional detection methods. For the purpose of environmental protection, so this article will use EDXRF to detect the content of K and other trace elements in the sample.

The characteristics of habitat, functional traits and medicinal components of Eucommia ulmoides from Guizhou.

To find out the genuine characteristics of Eucommia ulmoides produced in Guizhou.The habitat, functional characters and the content of medicinal components of Eucommia ulmoides in Guizhou were studied by using the method of sample survey combined with typical survey, related laboratory experiments and quantitative analysis. The results showed that the yield of Eucommia ulmoides plantation in Guizhou was divided into low altitude, low middle and high temperature rain slope latitude mixing, short sunshine hours type(A type), medium altitude, low longitude and latitude, high temperature rain, positive oblique steep slope, medium sunshine hours type (B type), middle altitude, low longitude and latitude, moderate high temperature rain, shady side and sunny side have gentle deflection steep slope, medium sunshine hours type (C type), High altitude, low longitude and latitude, low temperature moderate rain, positive gentle slope, long sunshine hours type (D type); Different types of Eucommia ulmoides plantation, Different habitat quality, B type is intensity karst rocky desertification habitat, A type is potential karst rocky desertification habitat, the C and D types are light and moderate rocky desertification areas, respectively, the species diversity of shrub layer in Eucommia ulmoides plantation was higher in D type and B type, A type and C type followed; There was no significant difference in root carbon content and leaf nitrogen content in 4 types of Eucommia ulmoides plantation, Among the four types of A, B, C, D, there were significant or extremely significant differences in other indexes of plant functional traits; Both genipinic acid and aucubin had the highest content of root bark, followed by trunk bark and lowest leaves, Chlorogenic acid is the opposite, The content of geniposide was higher in trunk bark and lower in root bark and leaves; Genipinic acid is higher in D type, Aucubin is higher in A and D type, Chlorogenic acid has higher leaves content in B type, Geniposide was the highest in trunk bark of D type; The element enrichment coefficient K and Mn leaves are the largest, the largest in trunk bark is Ca and Zn, Fe root bark is the largest; Effects of soil potassium, phosphorus, pH value and bulk weight on the functional traits of Eucommia ulmoides were significant. The contents of medicinal components in root bark, trunk bark, and leaves was influenced by species diversity of shrub layer, The contents of geniposide in root bark, aucubin in root bark and trunk bark, genipinic acid in bark and chlorogenic acid in leaves were particularly affected by soil physical and chemical indexes and metal element contents, The functional traits of Eucommia ulmoides can affect the content of medicinal components in root bark, trunk bark, and leaves, Especially on the root bark, trunk bark, and leaves in the content of aucubin content; The content of medicinal components of Eucommia ulmoides was high and stable. The above research results have important theoretical reference significance for the cultivation of Eucommia ulmoides and the cultivation of target medicinal components and the comprehensive exploitation and utilization of resources.

Mo-doped SnO2 nanotubes sensor with abundant oxygen vacancies for ethanol detection

This work describes a synthesizing method for Mo-doped SnO2 nanotubes (NTs) with uniform morphology by combining electrostatic spinning and air sintering. The method uses Mo ions to do substitutional doping of Sn ions in SnO2 to construct new lattice defects (such as oxygen vacancies), which provides more active sites for gas adsorption. Ethanol was taken as an example to study gas sensitivity characteristics of synthesized products. The analysis showed that 5 mol% of Mo-doped SnO2 nanotubes sensor exhibited the highest response (46.8) to 100 ppm ethanol at a lower optimum temperature (220 °C) and reduced the response/recovery time to 7/103 s. Also, it manifested excellent selectivity and long-term stability. The functionalized nanotubes structure and optimized parameters (oxygen vacancies concentration, metal vacancies defects, carrier concentration, catalytic sites, and base resistance increased) are the reasons for enhancing gas-sensing performance. This work provides direction that the optimal doping concentration of transition metal elements for metal-oxide NTs gas sensors can achieve the best sensing response.