Showing papers on "Fluorescence spectrometry published in 2015"
TL;DR: Measurements of tryptophan fluorescence (WF) for total protein determination in whole tissue lysates and for peptide quantification in protein digests demonstrate that the fluorescence spectrometry of tryPTophan offers a simple, sensitive, and direct method for protein and peptide assays.
Abstract: The determination of total protein content is one of the most frequent analytical tasks in biochemistry and molecular biology. Here we evaluate measurements of tryptophan fluorescence (WF) for total protein determination in whole tissue lysates and for peptide quantification in protein digests. We demonstrate that the fluorescence spectrometry of tryptophan offers a simple, sensitive, and direct method for protein and peptide assays. The WF assay is fully compatible with SDS and other solutes that are commonly used for lysis of tissue and cells. We found that the content of tryptophan varies only a little between mouse tissues (1.16 ± 0.08% of total amino acids) and is similar in human cells (1.19 ± 0.06%). Therefore, free tryptophan can be used as a universal standard. We show that the assay can be carried out on a standard fluorescence spectrometer with cuvettes as well as in a 96-well format using a plate reader. The method is particularly suitable for determination of peptide content in diluted samples. Notably, the whole sample can be recovered after the measurement.
198 citations
TL;DR: GO-SH can be applied to the arsenic speciation due to its selectivity toward arsenite and is suitable for the analysis of water, including high salinity samples difficult to analyze using other spectroscopy techniques.
Abstract: A new method based on dispersive microsolid phase extraction (DMSPE) and total-reflection X-ray fluorescence spectrometry (TXRF) is proposed for multielemental ultratrace determination of heavy metal ions and arsenic species. In the developed methodology, the crucial issue is a novel adsorbent synthesized by grafting 3-mercaptopropyl trimethoxysilane on a graphene oxide (GO) surface. Mercapto-modified graphene oxide (GO-SH) can be applied in quantitative adsorption of cobalt, nickel, copper, cadmium, and lead ions. Moreover, GO-SH demonstrates selectivity toward arsenite in the presence of arsenate. Due to such features of GO-SH nanosheets as wrinkled structure and excellent dispersibility in water, GO-SH seems to be ideal for fast and simple preconcentration and determination of heavy metal ions using methodology based on DMSPE and TXRF measurement. The suspension of GO-SH was injected into an analyzed water sample; after filtration, the GO-SH nanosheets with adsorbed metal ions were redispersed in a sma...
169 citations
TL;DR: In this article, the effect of source of palygorskite on the adsorption properties remains a gap to be filled, and a comparative study about the effect on the source of PGNs on the performance of methylene blue (MB) was conducted.
140 citations
TL;DR: In this paper, the ground state complex formation between CDs and HGB was effectively quenched by HGB due to the ground-state complex formation, and the static quenching mechanism was further investigated by UV-vis absorption spectrometry and time-resolved fluorescence spectra.
Abstract: In this work, we presented a rapid, selective and highly sensitive probe for hemoglobin (HGB) based on the quenched fluorescence of carbon dots (CDs). The CDs were synthesized by microwave irradiation technique in one pot according to our previous report. The fluorescence of CDs was effectively quenched by HGB due to the ground state complex formation between CDs and HGB. A number of key factors including the amount of CDs, pH value of phosphate buffer solution, the concentration of salt solution, and the reaction time those influenced the analytical performance of CDs in HGB determination were investigated thoroughly. Under the experimental conditions, the fluorescence intensity of CDs was inversely proportional to the concentration of HGB ranging from 1 to 4000 nM with a correlation coefficient of 0.9987. The limit of detection for HGB was as low as 0.12 nM. Some common substances, including other heme proteins, did not affect HGB determination significantly. The method was utilized to detect HGB in human urine and human blood samples with satisfactory results. The static quenching mechanism of this system was further investigated by UV–vis absorption spectrometry and time-resolved fluorescence spectrometry. The α-helix content of HGB decreased and the secondary structure of HGB was rearranged after the interaction with CDs.
118 citations
TL;DR: This study provides first direct spectroscopic evidence for Tl(I) uptake by illite and indicates the need for further studies on the sorption of Tl to clay minerals and Mn-oxides and its impact on Tl solubility in soils.
Abstract: We investigated the speciation and extractability of Tl in soil developed from mineralized carbonate rock. Total Tl concentrations in topsoil (0–20 cm) of 100–1000 mg/kg are observed in the most affected area, subsoil concentrations of up to 6000 mg/kg Tl in soil horizons containing weathered ore fragments. Using synchrotron-based microfocused X-ray fluorescence spectrometry (μ-XRF) and X-ray absorption spectroscopy (μ-XAS) at the Tl L3-edge, partly Tl(I)-substituted jarosite and avicennite (Tl2O3) were identified as Tl-bearing secondary minerals formed by the weathering of a Tl–As–Fe-sulfide mineralization hosted in the carbonate rock from which the soil developed. Further evidence was found for the sequestration of Tl(III) into Mn-oxides and the uptake of Tl(I) by illite. Quantification of the fractions of Tl(III), Tl(I)-jarosite and Tl(I)-illite in bulk samples based on XAS indicated that Tl(I) uptake by illite was the dominant retention mechanism in topsoil materials. Oxidative Tl(III)uptake into Mn-o...
113 citations
TL;DR: In this paper, the content, modes of occurrence, and origin of elements and phosphorus minerals in the Jurassic coals of the Muli Coalfield, on the Tibetan Plateau, were investigated using optical microscopy, field emission-scanning electron microscopy in conjunction with energy-dispersive X-ray spectrometry.
108 citations
TL;DR: In this article, Nanostructured chitosan/ZnO nanoparticle films were coated on mild steel by sol-gel process, dip coating technique, which has shown excellent chemical stability, oxidation control and enhanced corrosion resistance for metal substrates.
96 citations
TL;DR: In this article, the discovery of microplastic fibres in the seawater column and the chemical analysis of associated toxic chemicals in micro-plastic marine debris was reported. But the analysis of the micro-scale plastic was limited to microscopic particles.
Abstract: Environmental context Microplastics are a new source of toxic compounds in marine and freshwater environments. This research documents the discovery of microplastic fibres in the seawater column and the chemical analysis of associated toxic chemicals in microplastic marine debris. Microplastic pollution is pervasive and hazardous. Abstract Initial studies of floating plastic debris in the oceans dealt with macroscopic particles. This research found microscale plastic present as well. Chemical analysis of sorbed materials revealed toxic materials associated with the microparticles. Seawater and plastic fragment samples were collected in September 2007 in the North Pacific Central Gyre. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) were detected by mass spectrometry in extracts from the plastic fragments. Net concentrations of PCBs ranged from 1 to 223ngg–1 plastic. The most common synthetic polymers were found to be polypropylene and polyethylene. Microscopic plastic fibres and particles were also discovered in the seawater samples and examined by scanning electron microscopy. Analysis of filtered seawater samples also revealed toxic materials in concentrations lower than found on the plastic particles.
96 citations
TL;DR: A lanthanide-functionalized MOF with extremely high water tolerance was developed as a fluorescent probe for hippuric acid in urine which is considered as the biological indicators of toluene exposure for the first time.
91 citations
TL;DR: An approach to discretely measure sulfide and sulfide pools using the monobromobimane (MBB) method coupled with reversed phase high-performance liquid chromatography (RP-HPLC) with fluorescence detection of SDB is reported.
Abstract: The gasotransmitter hydrogen sulfide (H2S) is known as an important regulator in several physiological and pathological responses. Among the challenges facing the field is the accurate and reliable measurement of hydrogen sulfide bioavailability. We have reported an approach to discretely measure sulfide and sulfide pools using the monobromobimane (MBB) method coupled with reversed phase high-performance liquid chromatography (RP-HPLC). The method involves the derivatization of sulfide with excess MBB under precise reaction conditions at room temperature to form sulfide dibimane (SDB). The resultant fluorescent SDB is analyzed by RP-HPLC using fluorescence detection with the limit of detection for SDB (2 nM). Care must be taken to avoid conditions that may confound H2S measurement with this method. Overall, RP-HPLC with fluorescence detection of SDB is a useful and powerful tool to measure biological sulfide levels.
83 citations
TL;DR: The optical concept and the first measured performance of the Nanoscopium beamline is described followed by the hierarchical length-scale multi-technique imaging experiments performed with dwell times down to 3 ms per pixel.
Abstract: The Nanoscopium 155 m-long beamline of Synchrotron Soleil is dedicated to scanning hard X-ray nanoprobe techniques. Nanoscopium aims to reach ≤100 nm resolution in the 5–20 keV energy range for routine user experiments. The beamline design tackles the tight stability requirements of such a scanning nanoprobe by creating an overfilled secondary source, implementing all horizontally reflecting main beamline optics, applying high mechanical stability equipment and constructing a dedicated high-stability building envelope. Multi-technique scanning imaging and tomography including X-ray fluorescence spectrometry and spectro-microscopy, absorption, differential phase and dark-field contrasts are implemented at the beamline in order to provide simultaneous information on the elemental distribution, speciation and sample morphology. This paper describes the optical concept and the first measured performance of the Nanoscopium beamline followed by the hierarchical length-scale multi-technique imaging experiments performed with dwell times down to 3 ms per pixel.
TL;DR: Results indicated that an advanced fused model where VisNIR DRS spectra-based penalized spline regression (PSR) was used to predict total petroleum hydrocarbon followed by PXRF elemental data-based random forest regression was used and outperformed all other models tested.
TL;DR: The results suggested that high-sensitivity automated SPFS immunoassay systems might become a powerful tool for the diagnosis of PC and other diseases.
Abstract: A high-sensitivity immunoassay system with surface plasmon field-enhanced fluorescence spectrometry (SPFS) was constructed using a plastic sensor chip and then applied to the detection of total prostate-specific antigen (total PSA) and GalNAcβ1-4GlcNAc-linked prostate-specific antigen (LacdiNAc-PSA) in serum, to discriminate between prostate cancer (PC) and benign prostate hyperplasia (BPH). By using this automated SPFS immunoassay, the detection limit for total PSA in serum was as low as 0.04 pg/mL, and the dynamic range was estimated to be at least five digits. A two-step sandwich SPFS immunoassay for LacdiNAc-PSA was constructed using both the anti-PSA IgG antibody to capture PSA and Wisteria floribunda agglutinin (WFA) for the detection of LacdiNAc. The results of the LacdiNAc-PSA immunoassay with SPFS showed that the assay had a sensitivity of 20.0 pg/mL and permitted the specific distinction between PC and BPH within the PSA gray zone. These results suggested that high-sensitivity automated SPFS immunoassay systems might become a powerful tool for the diagnosis of PC and other diseases.
TL;DR: In this paper, the extent of contamination in bottom sediments of Qaroun Lake, El-Fayoum, Egypt is assessed using the contamination indicators, the geo-accumulation index, Igeo and contamination factor, Cf and the degree of contamination, Cd.
TL;DR: Good agreement was observed between CFD predictions and experimental measurements with similar deposition trends in each region of interest, demonstrating the use of a sectioned nasal CFD model based on anatomical regions of interest for nasal drug delivery to elucidate patterns of regional deposition within a human nasal cavity.
Abstract: Background: Knowledge of the regional deposition of inhaled particles in the nose is important for drug delivery and assessment of the toxicity of inhaled materials. In this study, computational fluid dynamics (CFD) predictions and experimental measurements in a nasal replica cast were used to study regional deposition of inhaled microparticles. Methods: The replica cast was sectioned into six regions of interest based on nasal anatomy: the nasal vestibule, nasal valve, anterior turbinates, olfactory region, turbinates, and nasopharynx. Monodisperse fluorescein particles with aerodynamic diameters of 2.6–14.3 μm were passed through the assembled cast in the presence of steady inspiratory airflow at 15 L/min. After each experiment, the cast was disassembled and the deposited fluorescein in each region was washed out and quantified with fluorescence spectrometry. A nasal CFD model was developed from the same magnetic resonance imaging scans that were used to construct the replica cast. Steady-state...
TL;DR: In this paper, a plant-based catalyst Eco-Mn was proposed for styrene epoxidation with only 0.31 mol % Mn, a much lower content of Mn than in previous studies.
Abstract: A novel Mn-derived catalyst was prepared starting from the biomass of Mn-hyperaccumulating plants growing on metal-rich soils. Recovery of this biomass as value-added “ecocatalyst” provides incentives for the development of phytoextraction programs on soils degraded by mining activities. Characterization of the resulting plant-based catalyst Eco-Mn by inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), and X-ray photoelectron spectroscopy (XPS) demonstrated the presence of unusual polymetallic complexes of Mn(II) in the catalyst, along with Fe(III). Incorporation of these species into montmorillonite K10 as solid support provided a supported Eco-Mn catalyst, whose properties were investigated for alkene epoxidation with H2O2 (30 wt %)/NaHCO3 (0.2 M) as a green terminal-oxidizing reagent. The supported Eco-Mn catalyst demonstrated a high efficiency for styrene epoxidation, with only 0.31 mol % Mn, a much lower content of Mn than in previous...
Paul Scherrer Institute1, Lucerne University of Applied Sciences and Arts2, European XFEL3, King's College London4, University of Manchester5, University of California, Davis6, Karlsruhe Institute of Technology7, University of Washington8, Georgia Institute of Technology9, University of Reading10, University of Leicester11
TL;DR: In this article, the authors measured trace element concentrations in London during winter 2012 using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF).
Abstract: . Ambient concentrations of trace elements with 2 h time resolution were measured in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 10.4 to 16.6 for SW winds (3.3–6.9 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.7 to 8.2 for SW (2.6–3.0 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10–2.5 mass fraction, roughly twice that of the PM1.0–0.3 fraction. These elements also showed the highest urban increments (~ 3.0), although no difference was observed between brake wear and other traffic-related elements. All elements influenced by traffic exhibited higher concentrations during morning and evening rush hours, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Si, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (3.4–5.4 for SW, 1.7–2.3 for NE) and urban (~ 2) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10–2.5 sea salt (factor of up to 2), which may be influenced by traffic-induced resuspension of sea and/or road salt. Heavy-duty vehicles appeared to have a larger effect than passenger vehicles on the concentrations of all elements influenced by resuspension (including sea salt) and wearing processes. Trace element concentrations in London were influenced by both local and regional sources, with coarse and intermediate fractions dominated by traffic-induced resuspension and wearing processes and fine particles influenced by regional transport.
TL;DR: In this article, a comparative analysis of a set of copper-based objects by means of portable X-ray fluorescence (pXRF) and electron probe microanalyser (EPMA) is presented.
Abstract: Analysis of metal objects with portable and handheld X-ray fluorescence spectrometry has become increasingly popular in recent years. Here, methodological concerns that apply to non-destructive, surface examination with XRF instruments of ancient metal artefacts are discussed based on the comparative analyses of a set of copper-based objects by means of portable X-ray fluorescence (pXRF) and electron probe microanalyser (EPMA). The analytical investigation aims to explore issues of instrument comparability and reliability of the non-invasive pXRF results. The different analytical approaches produce a comparable pattern for the major element concentrations, but substantial variation is evident when it comes to the absolute values for major and minor/trace elements.
TL;DR: In this paper, the efficiency of W-doped TiO2 in the photocatalytic degradation of 4-chloro-2-methylphenoxyacetic acid (MCPA) was investigated.
Abstract: This work was aimed at studying the efficiency of W-doped TiO2 in the photocatalytic degradation of 4-chloro-2-methylphenoxyacetic acid (MCPA). Different wt.% of W-doped TiO2 was synthesized via the sol–gel method and characterized. The characterizations included powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), N2 sorption, Raman spectroscopy, fluorescence spectrometry, and electron spin resonance spectroscopy (ESR). Result from the BJH pore size distribution shows the materials are mesoporous with BET surface area ranging from 86.08–91.71 m2/g. All materials showed polycrystalline anatase phase with decreasing crystal size as the percentage dopant increases. The best photocatalytic activity was obtained with 0.1 wt.% W-doped TiO2 (0.1 WT) at a natural pH of 5, which may have resulted from its relatively reduced band gap; crystal size; and lesser amount of oxygen vacancy. 0.1 WT had an optimum catalyst concentration of 600 mg/L under artificial light irradiation at a rate constant and half-life of 4.31 × 10−3 s−1 and 160 s, respectively. The intermediates/products as analyzed by the LC-MS were 2-hydroxybuta-1, 3-diene-1, 4-diyl-bis (oxy) dimethanol and 2-(4-hydroxy-2-methylphenoxy) acetic acid which are relatively safer than MCPA.
TL;DR: In this article, a peat layer at a depth of 6m below ground was found to be an important source, source, or sink of arsenic in the Mekong Delta.
TL;DR: The proposed DMSPE/EDXRF procedure was successfully applied for the determination of Se in mineral, tap, lake and sea water samples as well as in biological materials (Lobster Hepatopancreas and Pig Kidney).
TL;DR: In this paper, an adaptation of Terephthalic acid (TA) as probe method for fluorescence spectrometry (TA-FL method) for construction materials was used to quantify the production of hydroxyl radicals (OH) by several photocatalytic cementitious materials.
TL;DR: In this article, the surface functional groups of CDs were investigated with the help of Fourier transformation infrared spectroscopy and ultraviolet-visible (UV-vis) spectrophotometry.
Abstract: Carbon dots (CDs) were hydrothermally synthesized using citric acid as carbon source and ethylenediamine as additive. The as-obtained CDs were then subjected to ultraviolet (UV) irradiation, resulting in ultraviolet-irradiated CDs (UVCDs). The morphology and size of CDs were characterized by transmission electron microscopy. Elemental analysis (EA) was employed to explore the composition of CDs. The surface functional groups of CDs were investigated with the help of Fourier transformation infrared spectroscopy. Fluorescence spectrometry and ultraviolet-visible (UV-vis) spectrophotometry were used to characterize the optical properties of CDs and UVCDs. The results show that the size of CDs was around 10 nm. C, H, O, and N constituted CDs with the empirical elemental composition CH1.26O0.52N0.22. Apart from excitation-independent photoluminescence (PL), CDs exhibited two UV-vis absorption peaks at 340 and 451 nm. They also revealed weak near infrared (NIF) emission with excitation at 340 and 360 nm. In add...
TL;DR: In this paper, a portable X-ray fluorescence spectrometer was used to determine the origin of high trace element concentrations (arsenic and lead) in an urban community garden.
Abstract: Due to their location on old urban sites, impacted by human activities or road traffic, soils in urban gardens are often contaminated with a range of contaminants that could pose health risks. The aim of this study is to determine the origin of high trace element concentrations (arsenic and lead) in an urban community garden. Trace elements were quantified in situ in the topsoil (0–20 cm) of the 95 plots of the garden and in four soil profiles, using a portable X-ray fluorescence spectrometer. The accuracy of the spectrometer results was checked by measuring trace element concentrations by inductively coupled plasma mass spectrometry (ICP-MS) after an acid digestion (HF and HClO4). Leafy and root vegetables were sampled to assess lead transfer in vegetables. The accumulation of lead in vegetables was measured by ICP-MS after an aqua regia digestion. The bioaccessibility of lead was estimated by a calcium chloride extraction. Three anomaly levels could be defined from the mapping of arsenic and lead on the whole garden. The increase of trace elements content with depth, in correlation with pedological/geological characteristics, supports the hypothesis of a geogenic origin of these anomalies. The enrichment of the topsoil is related to the pedogenesis of soil, from micaschists as parent material. The geogenic origin of lead does not prevent its accumulation by vegetables. Although trace element anomalies have generally an anthropogenic origin, some anomalies may also have a natural (geogenic) origin, as shown in this study. The comprehension of lead origin, the mapping of its spatial distribution in the garden and the characterisation of its accumulation in vegetables were used as a basis for operational decisions including soil management. X-ray fluorescence spectrometry is a well-adapted method for this purpose. It allows an in situ and fast semiquantitative investigation on a lot of sampling points, saving time and laboratory analysis cost.
TL;DR: This research provides better understanding of the extractability of each metal and improves the awareness of potential obstacles for extraction, which will lead to smarter decisions during further development of a clean and effective recovery process.
TL;DR: The results demonstrated that the proposed approach can be used to study soil contamination to produce geochemical maps, and identify hot-spot areas for soil Pb concentration, and demonstrate that these polluted areas were quite large and likely to create a significant health risk for human beings and vegetation in the near future.
Abstract: Exposure to lead (Pb) may affect adversely human health. Mapping soil Pb contents is essential to obtain a quantitative estimate of potential risk of Pb contamination. The main aim of this paper was to determine the soil Pb concentrations in the urban and peri-urban area of Cosenza–Rende to map their spatial distribution and assess the probability that soil Pb concentration exceeds a critical threshold that might cause concern for human health. Samples were collected at 149 locations from residual and non-residual topsoil in gardens, parks, flower-beds, and agricultural fields. Fine earth fraction of soil samples was analyzed by X-ray Fluorescence spectrometry. Stochastic images generated by the sequential Gaussian simulation were jointly combined to calculate the probability of exceeding the critical threshold that could be used to delineate the potentially risky areas. Results showed areas in which Pb concentration values were higher to the Italian regulatory values. These polluted areas were quite large and likely, they could create a significant health risk for human beings and vegetation in the near future. The results demonstrated that the proposed approach can be used to study soil contamination to produce geochemical maps, and identify hot-spot areas for soil Pb concentration.
TL;DR: In this article, the authors investigated the fusion characteristics of three low-rank coals and cornstalk mixtures by ash fusion temperature (AFT) analysis, X-ray fluorescence spectrometry, scanning electron microscopy, and Xray diffractometry.
TL;DR: In this article, the effect of count time on the precision and accuracy of portable X-ray fluorescence spectrometry (pXRF) data obtained for two geologic standards, as well as for obsidian, fine-grained volcanic (e.g., andesites, dacites), metamorphic, and chert specimens from the North American Great Basin.
TL;DR: Different non- invasive and micro-invasive techniques were used and the possibility to distinguish between folium and orchil by chemical analysis is discussed.
TL;DR: Wang et al. as discussed by the authors used correlation analysis, principal component analysis and cluster analysis to identify the potential sources of heavy metals in smaller than 100 μm dust from Xining, China, and found that the mean concentrations of Co, Cr, Cu, Mn, Ni, Pb, V and Zn in the studied samples were 50.0, 576.8, 40.6, 52.9, 57.1 and 108.9 mg kg−1.
Abstract: Concentrations of Co, Cr, Cu, Mn, Ni, Pb, V and Zn in less than 100 μm particles of street dust from Xining, China were measured by wavelength dispersive X-ray fluorescence spectrometry. Correlation analysis, principal component analysis and cluster analysis were used to identify the potential sources of heavy metals in smaller than 100 μm dust. The results showed that the mean concentrations of Co, Cr, Cu, Mn, Ni, Pb, V and Zn in the studied samples were 50.0, 576.8, 40.8, 408.8, 22.6, 52.9, 57.1 and 108.9 mg kg−1, which were 5.0, 8.2, 1.8, 0.7, 0.8, 2.5, 0.8 and 1.4 times the corresponding background value of Qinghai soil, respectively. Compared with Qinghai soil, Co, Cr, Cu, Pb and Zn presented accumulation with different degrees in smaller than 100 μm dust of Xining, especially Cr and Co which were markedly enriched, whereas Mn, Ni and V were deficient. Four main sources were identified based on the results of correlation analysis, principal component analysis and cluster analysis. Ni, V and Cr originated from nature (local soil) and industrial sources (steel plant, metal processing factory, coal power plant). Cu, Pb and Zn mainly derived from traffic source. Mn and Co mainly originated from local soil and construction sources (coating material and paint, etc.), respectively.