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The complete characterization of selenium-enriched yeast in terms of selenium species has been the goal of extensive research for the last three decades. This contribution addresses the two outstanding questions: the mass balance of the identified and reported selenium species and the possible presence of inorganic selenium. For this purpose, four procedures have been designed combining, in diverse order, the principal steps of selenium speciation analysis in Se-rich yeast: extraction of the Se-metabolome, derivatization of cysteine and Se-cysteine (SeCys) residues, proteolysis, and definitive Se recovery using SDS extraction, followed by mineralization. The recovery of selenium in each step and its speciation were controlled by ICP MS and by reversed-phase HPLC-ICP MS, respectively. The study, carried out for the SELM-1 reference material, demonstrated the presence of about 10% of inorganic selenium and a serious risk of losses of SeCys during derivatization and proteolysis. As result of our work, we postulate the following values for SELM-1: Se-metabolome fraction (SeMF) 14.8 ± 0.7%; total selenomethionine (SeMet) 66.2 ± 2.7% (including ca. 1.5% SeMet present in the SeMF); total SeCys 12.5 ± 1.5% (including 2% of SeCys present in the Se-MF); total inorganic selenium 9.7 ± 1.7%, accounting for > 99.8% of the selenium. [ABSTRACT FROM AUTHOR]

The release of nickel "Ni(II)" into aquatic environments is of great concern because of environmental and health issues. Metal-organic frameworks (MOFs) are one of the most promising technologies for removing heavy metals from water. In this work, an octahedral Co-based MOF (Co-MOF) was synthesized with a high Ni(II) removal capacity (qmax of 1534.09 ± 45.49 mg g−1) in aqueous media. For the first time, the effect of Co-MOF alone and in co-exposure with Ni(II) on nitrifying microbial consortium was assessed using dynamic microrespirometry. A single concentration of Co-MOF had no significant effects on nitrifying microbial consortium, while the concentration of Ni(II) exerted non-competitive inhibition on the nitrifying microbial consortium with an IC50 of 1.67 ± 0.03 mg L−1. In addition, the theoretical speciation analysis showed a decrease of 40% of IC50 when the free Ni(II) concentration was considered. Co-exposure of Co-MOF and Ni(II) during the nitrifying process allowed us to conclude that Co-MOF is an effective adsorbent for Ni(II) and can be used to mitigate the inhibitory effects of nickel on nitrifying microbial consortia, which is crucial for maintaining the good operation of wastewater treatment and balance of nitrogen cycle. [ABSTRACT FROM AUTHOR]

This study addresses the development and validation of an analytical method for speciation analysis of mercury (inorganic/Hg2+ and methylmercury/CH3Hg+) in fishery products. The Hg species are separated by reversed-phase (RP) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The effective separation of Hg2+ and CH3Hg+ was achieved in <8 min using a peptide mapping RP column and a mobile phase containing 2-mercaptoethanol at 0.25% (v/v) and methanol at 1% (v/v). The optimization was carried out using an experimental design through response surface methodology (RSM) with central composite design (CCD), addressing both the HPLC separation and the sample extraction. The method validation was carried out based on the accuracy profile approach. For this purpose, six series of measurements were carried out in duplicate over a time span of 2 months. The limits of quantification (LOQ) were 2.5 µg/kg (wet weight, ww) for CH3Hg+ and 1.2 µg/kg (ww) for Hg2+. The intermediate reproducibility in terms of coefficient of variation (CVR) was <6%. The bias (%) obtained for the analysis of four certified reference materials (CRMs), namely TORT-3 (lobster hepatopancreas), SRM 1566-b (oyster tissue), SQID-1 (cuttlefish) and NMIJ CRM 7402-a (cod fish tissue) was <7%. This demonstrates the method robustness and suitability for routine speciation analysis of CH3Hg+ and Hg2+ in fishery products. The method is intended to be applied for the analysis of the panel of fishery products and fish-based foods in the framework of the (ongoing) third French Total Diet Study. [ABSTRACT FROM AUTHOR]

Introduction: Environmentally friendly and efficient biochar precursor materials and their modification methods are of great significance in solving the problem of soil cadmium pollution. Materials and methods: This study prepared apple pomace biochar (ABC) from discharged apple pomace by pyrolysis at 500 °C. ABC was modified by phosphoric acid impregnation (P-ABC), MnO2 loading (Mn-ABC), and MnO2 loading after phosphoric acid impregnation (Mn-P-ABC). The biochar and modified biochar were described by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The impacts of original and modified biochar on soil characteristics and the immobilization of original and modified biochar with different additions (4, 7, 10 and 13%) on Cd in contaminated soils were studied. Results and discussion: The outcomes show that ABC, P-ABC, Mn-ABC, and Mn-P-ABC are porous and amorphous materials rich in functional groups. All four types of biochar can enhance soil organic matter content, cation exchange capacity, and pH value, effectively improving soil properties. After application of biochar materials, the extractable Cd in soil was obviously reduced compared to the control, and 13% Mn-P-ABC reduced the extractable Cd in the soil by 43.84%. The results of Cd speciation analysis indicate that after the application of biochar materials, the acid soluble Cd in the soil reduced and the residual Cd increased. Conclusions: The treatment with 13% Mn-P-ABC resulted in a 35.57% decrease in acid soluble Cd in soil and a 30.18% increase in residual Cd, indicating the best immobilization effect on Cd. [ABSTRACT FROM AUTHOR]

Heavy metal pollution from compost is one of the most concerned environmental problems, which poses a threat to the ecosystem and human health. This study aims to reveal the heavy metal tolerance and detoxification mechanism mediated by heavy metal resistance genes (HMRGs) in compost habitat through metagenomics combined with chemical speciation analysis of heavy metals. The results showed that there were 37 HMRGs corresponding to 7 common heavy metal(loid)s in composting, and they had the ability to transform heavy metals into stable or low-toxic speciation by regulating enzyme transport, redox, methylation, etc. This study summarized the heavy metal metabolism pathway mediated by HMRGs, providing a new perspective for understanding the transformation of heavy metals in the composting process. [ABSTRACT FROM AUTHOR]

The aim of this work is to develop a simple, sensitive, and reliable colorimetric test method for the visual detection of Fe(II) and Fe(III) in water. The sample solution of Fe(III) was initially complexed with chromeazurol S (CAS) followed by ion-pair association with cetyltrimethylammonium bromide (CTAB) in the presence of perchlorate ions. This led to the formation of a bulky and insoluble fluffy precipitate involving the physical entrapment of the ternary complex of Fe-CAS-CTAB, which floats on the top of the solution. Depending on the concentration of Fe(III), this type of ternary complex produces an impressive color change from reddish magenta to purple and then to cyan-blue, easily detectable with the naked eye without the need for expensive instrumentation. The ternary-colored complex was formed instantly and remained stable for at least 8 h with constant absorbance. For the determination of total iron and Fe(II), complete oxidation of Fe(II) to Fe(III) was carried out using 100 μL of KMnO4 (0.005%). The minimal response with the test method was found to be about 5 ng/mL of Fe(III) in 2 min of the total sample testing procedure. However, Fe(III) could be quantified using a spectrophotometer after dissolving the fluffy precipitate in toluene solvent. The calibration graph was linear in the range of 5–30 ng/mL of Fe(III) with a correlation coefficient of 0.9931 and a limit of detection of 0.9 ng/mL. The relative standard deviation was found to be less than 6%. At the end of the study, the efficacy of the method was evaluated by its application to groundwater and thermal power plant coolant waters. [ABSTRACT FROM AUTHOR]

In the last decades, the determination of trace elements in biological materials has emerged as an important area of study because of its relevance to human health and the environment. Inductively coupled plasma mass spectrometry (ICP-MS) has proven to be a powerful tool for trace element analysis, owing to its high sensitivity and ability to determine several elements in a single measurement. However, given the complex nature of biological matrices and the presence of elements, most of them at ultratrace levels, it becomes crucial to complement ICP-MS with preconcentration techniques to increase the sensitivity and selectivity of analytical methods. This article presents an exhaustive overview of liquid- and solid-phase preconcentration techniques used in combination with ICP-MS for trace element determination in different biological samples from 2000 to the present. An in-depth discussion of the advances on the application of state-of-the-art solvents and materials in trace element extraction and preconcentration is presented. Special attention is given to different strategies for elemental speciation analysis, employing both chromatographic and non-chromatographic techniques. The role of automation in these methodologies is also described. Finally, future trends and challenges related to this topic are discussed. [ABSTRACT FROM AUTHOR]

Speciation analysis plays a key role in understanding the biological activity and toxicity of an element. So far, classical speciation analysis focused only on the dissolved fraction of an elemental species, whereas nanoparticle forms of analytes are being widely found in consumer and industrial products. A significant contributor to human exposure to nanoparticles is through food into which nanoparticles can be incorporated from endogenous sources or they may be formed naturally in the living organisms. Nanoparticles often undergo changes in the food matrices and upon consumption, in the gastrointestinal tract, which present a significant challenge to their characterisation. Therefore, a combination of both classical and nanoparticle speciation analytical techniques is needed for the characterisation of both dissolved and particulate forms of the chemical species. This article presents and discusses the current trends in analysis of nanoparticle behaviour in the gastrointestinal tract and formation and characterisation of biogenic nanoparticles. [ABSTRACT FROM AUTHOR]

Arsenic, which can be divided into inorganic and organic arsenic, is a toxic metalloid that has been identified as a human carcinogen. A common source of arsenic exposure in seafood is arsenolipid, which is a complex structure of lipid-soluble organic arsenic compounds. At present, the known arsenolipid species mainly include arsenic-containing fatty acids (AsFAs), arsenic-containing hydrocarbons (AsHCs), arsenic glycophospholipids (AsPLs), and cationic trimethyl fatty alcohols (TMAsFOHs). Furthermore, the toxicity between different species is unique. However, the mechanism underlying arsenolipid toxicity and anabolism remain unclear, as arsenolipids exhibit a complex structure, are present at low quantities, and are difficult to extract and detect. Therefore, the objective of this overview is to summarize the latest research progress on methods to evaluate the toxicity and analyze the main speciation of arsenolipids in seafood. In addition, novel insights are provided to further elucidate the speciation, toxicity, and anabolism of arsenolipids and assess the risks on human health. [ABSTRACT FROM AUTHOR]

The removal of copper (Cu) in soils by green technology is less treated with urgency, as it is a plant micronutrient. We examined the efficiency of Cu shoot accumulation by herbaceous plants in Cu-contaminated and non-contaminated soils in Trhové Dusniky and Podles, respectively, in the Czech Republic. The total soil Cu content of 81 mg kg−1 in Trhové Dusniky indicated a slight contamination level compared to 50 mg kg−1, the permissible value by WHO, and < 35 in Podlesí, representing a clean environment. The Cu content was above the permissible value in plants (10 mg kg−1 by WHO) in herbaceous speciesat the control site without trees: Stachys palustris L. (10.8 mg kg−1), Cirsium arvense L. (11.3 mg kg−1), Achillea millefolium L. (12.1 mg kg−1), Anthemis arvense L. (13.2 mg kg−1), and Calamagrostis epigejos L. (13.7 mg kg−1). In addition, Hypericum maculatum Crantz (10.6 mg kg−1), Campanula patula L. (11.3 mg kg−1), C. arvense (15 mg kg−1), and the highest accumulation in shoot of Equisetum arvense L. (37.1 mg kg−1), all under the canopy of trees at the uncontaminated site, were above the WHO value. Leucanthemum Vulgare (Lam.) and Plantago lanceolata L. recorded 11.2 mg kg−1 and 11.5 mg kg−1, respectively, in the soil of the Cu-contaminated site. These herbaceous species can support the phyto-management of Cu-contaminated soils, especially E. arvense. Critical attention is well-required in the medicinal application of herbaceous plants in treating human ailments due to their Cu accumulation potentials above the threshold. Spontaneous surveys and analysis of Cu speciation in herbaceous species can reveal suitable plants to decontaminate soils and provide caution on consumable products, especially bioactive compounds. [ABSTRACT FROM AUTHOR]

Levels of 14 trace elements (Al, Ti, V, Cr, Mn, Co, Ni, Zn, As, Se, Cd, Sn, Hg, and Pb) and 5 arsenic species (arsenite/As(III), arsenate/As(V), monomethylarsonic acid/MA, dimethylarsinic acid/DMA, and arsenobetaine/AsB) were assessed in the gonads of sea urchin samples (Paracentrotus lividus) from North-West Mediterranean Sea (French coast). The samples were collected from 13 sites characterized by different types and levels of chemical contamination. Trace elements levels were measured by inductively coupled plasma-mass spectrometry (ICP-MS) following microwave (acid) digestion in a closed system, whereas As speciation analysis was carried out by ion-exchange liquid chromatography coupled with ICP-MS after microwave-assisted extraction. High levels of trace elements were found in sea urchins sampled from Corsica whereas the samples from Théoule were found to be the least contaminated. From all the analyzed urchin samples, none showed Cd, Hg, or Pb concentrations above the regulatory levels set by the European Community (EC) No. 1881/2006 for seafood or bivalve mollusks. Regarding arsenic speciation, AsB was confirmed to be the predominant species. Inorganic As (As(III) + As(V)) was mainly constituted by As(III), which was quantified in all samples. Methylated As forms (MA and DMA) represent 9 to 23% of the total As. [ABSTRACT FROM AUTHOR]

The electroplating process of copper pyrophosphate (Cu2P2O7) results in the production of a large volume of wastewater that contains a high concentration of copper (Cu). Currently, conventional lime precipitation creates a substantial amount of secondary pollution, which adds extra economic and environmental burdens. In this study, we suggest a straightforward method for on-site recovery of Cu from Cu2P2O7 electroplating wastewater. By optimizing various parameters, characterizing the resulting product, assessing its electroplating capabilities, and analyzing the speciation during the reaction, we comprehensively investigated the feasibility and mechanism of this technique. The results demonstrated that, under the optimal conditions (Cu/P molar ratio of 0.96, pH of 5.0, and a reaction time of 5.0 min), the concentration of residual Cu remained stable between 22.2 and 27.7 mg/L, even when the initial Cu concentrations varied. The addition of Cu triggered a series of hydrolysis and ionization reactions, primarily leading to the formation of Cu2P2O7·3H2O. The harvested Cu2P2O7·3H2O proved to be suitable for practical electroplating applications, exhibiting comparable performance to commercially available Cu2P2O7·3H2O. This demonstrates the feasibility of recovering high-purity Cu2P2O7·3H2O from copper electroplating wastewater, offering a promising approach for on-site copper reuse and concurrently reducing the demand for natural copper resources. Furthermore, this approach significantly reduces the generation of solid waste, aligning with the principles of sustainable development. [ABSTRACT FROM AUTHOR]

This study reports the development and validation of a new analytical method for simultaneous speciation analysis of Se and Hg in fish muscle. For this purpose, four Se species (selenite/Se(IV), selenate/Se(VI), selenomethionine/SeMet, and selenocysteine/SeCys) and two Hg species (inorganic mercury/iHg and methylmercury/MeHg) were extracted simultaneously by microwave-assisted enzymatic hydrolysis and then separated by HPLC in less than 15 min by using a column with both anion and cation exchange mechanisms and a mobile phase consisting of a mixture of methanol 5% (v/v), 45 mM HNO3, 0.015% 2-mercaptoethanol, and 1.5 mM sodium 3-mercapto-1-propanesulfonate. The separated species of Hg and Se were detected online by inductively coupled plasma-mass spectrometry (ICP-MS). The speciation analysis method was validated by means of the accuracy profile approach by carrying out three series of measurements in duplicate on three different days over a time-span of 3 weeks. The limits of quantification (LOQ) are in the range of 0.010–0.013 mg/kg wet weight (ww) for all selenium species, except for Se(IV) (0.15 mg/kg ww), while the coefficient of variation in terms of intermediate reproducibility (CVR) was < 7%. The LOQ for MeHg was 0.006 mg/kg ww, while the CVR was 3%. The method was successfully applied to the analysis of muscle samples from four different fish species: rainbow trout, tuna, swordfish, and dogfish. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the distribution of relevant inorganic contaminants in environmental samples from Ciudad de la Costa, the second most populated city of Uruguay. For this task aluminum (Al), cadmium (Cd), chromium (Cr), nickel (Ni) and lead (Pb) levels were determined in sand, water, and plant material from six beaches that are located in the area. Analytical methods were successfully validated. Accuracy was ensured by using certified reference materials and spiking procedures. Average metal concentrations in sand and water samples were compared with the maximum limits established by international or national regulations (when available), being far below these limits in all cases. This may indicate that the inorganic contamination in the studied area is rather low, despite the rapid increase in anthropic activities in recent years. To give a deeper characterization of the ecosystem, metal accumulation and mobility within a common plant of the zone, Ammophila arenaria, were studied. Results showed that concentrations in roots were one order of magnitude higher in comparison to aerial parts. In addition, the bioaccumulation coefficient (BAC) showed that the plant accumulates Cd, Cr and Ni, while a low accumulation for Pb was observed. Finally, a Cr(VI) speciation analysis in Ammophila arenaria was performed, showing Cr(VI) percentages below 4.6%, which is relevant from the (eco)toxicological point of view due to the high environmental mobility and bioavailability of this valence state. This work constitutes the first environmental surveillance report of this kind, regarding this populated area of the country. [ABSTRACT FROM AUTHOR]

Sb speciation analysis is important in relation to industrial exposure or environmental release because of the large difference in toxicity between SbIII and SbV. In this study, the release of Sb species from a semiconductor material (undoped and Bi-doped InSb thin films) in 0.1 mol/L sodium acetate buffer was investigated using hydride generation–microwave plasma-atomic emission spectroscopy (HG–MP-AES). Total Sb was determined using our previously reported method, and SbIII concentration was measured without reduction by potassium iodide and with a lower sodium tetrahydroborate/sodium hydroxide concentration. To estimate the SbV concentration, the SbIII concentration was subtracted from the total Sb concentration. The Sb species were not changed by Bi doping, even though Bi doping suppressed the Sb elution from the thin films. A large fraction of Sb eluted as SbIII during leaching for 28 days. This is the first Sb speciation analysis using HG–MP-AES of eluates from Sb-based materials. Sb speciation analysis using HG–MP-AES is cost effective, reliable, and requires only simple sample preparation. [ABSTRACT FROM AUTHOR]

The effect of the presence of gasoline and diesel on the speciation and mobility of inorganic arsenic species in tropical topsoils was investigated. Topsoil samples (n = 25) were contaminated with gasoline and diesel (500 mg kg−1) in laboratory and were incubated under unsaturated conditions and regular aeration for 21 days. Speciation analysis and chemical fractionation were performed in the pore water from control, gasoline, and diesel-contaminated soil samples. Arsenic concentrations were compared to microbiological parameters (microbial metabolic quotient and soil basal breathing) and the presence of ArsM-harboring bacteria. The spike of gasoline and diesel to the topsoils increased pore water As3+ (H3AsO3) concentration. Arsenic mobilization was lower compared to previously reported data for other sources of organic matter (biochar, litter, and a mixture of sphagnum peat moss and composted poultry manure). However, gasoline or diesel addition mobilized As fractions that were adsorbed to the solid phase, in approximately 60% of the soils. Methylation presented an important role in the As3+ regulation in control soils, which was no longer observed after gasoline or diesel addition. The quantification of the labile fractions sampled by the diffusive gradients in thin films technique showed that the increased As concentration in the gasoline or diesel-contaminated soils mostly included inert species. Dissolved organic carbon content seems to be an important control mechanism of the labile As concentration. The increase in As mobility seems to pose a more concerning scenario due to As leaching than to plant uptake. [ABSTRACT FROM AUTHOR]

Mobility and bioavailability of radionuclides in the environment strongly depend on their aqueous speciation, adsorption behavior and the solubility of relevant solid phases. In the present context, we focus on naturally occurring Th-232 at a location in central Sri Lanka presenting high background radiation levels. Four different soil samples were characterized using X-ray Absorption Spectroscopy (XAS) at the Th L3-edge (16.3 keV), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) spectroscopy. X-ray Absorption Near Edge Structure (XANES) spectra are applied as a fingerprint indication for Th existing in different chemical environments. Linear combination fitting (LCF) of the Extended X-ray Absorption Fine Structure (EXAFS) data involving reference Th-monazite (phosphate) and thorianite (oxide) compounds suggested that Th is mostly present as Th-phosphate (76 ± 2%) and Th-oxide (24 ± 2%), even though minor amounts of thorite (silicate) were also detected by SEM–EDX. Further studies on selected individual particles using micro-focus X-ray Fluorescence (μ-XRF) and micro-X-ray Absorption Spectroscopy (μ-XAS) along with SEM–EDX elemental mapping provided information about the nature of Th-bearing mineral particles regarding mixed phases. This is the first study providing quantitative and XAS based speciation information on Th-mineral phases in soil samples from Sri Lanka. [ABSTRACT FROM AUTHOR]

Studies in the field of microelement speciation in the body of farm animals, in particular dairy cattle, are almost completely absent. The average concentration of Mn in the blood serum of all the studied animals (n = 80) was 2.5 μg/L, which corresponds to normal values. Of the total number of animals, 21% were the cows with the low normal values (serum Mn concentration ≤ 2 µg/L, i.e. less than Q25 of the total sample) and 25% were the animals with the high normal values (serum Mn concentration ≥ 2.72 µg/L, i.e. more than Q75 of the total sample). The data obtained in the course of the study indicate that the change in the Mn level, even in the range of normal values, is accompanied by the redistribution of this element over various protein fractions. The six found Mn blood serum forms are presumably represented by α2-macroglobulin (tetramer, dimer, and monomer), transferrin/albumine, manganese citrates, and "free" metal ions. The analyzed fractions of Mn found in the blood serum of cows had the following hierarchy of concentrations: in the group with low-normal values of Mn ("free" Mn >> tetrameric form of α2-macroglobulin >> transferrin/albumine >> dimeric form of α2-macroglobulin >> monomeric form of α2-macroglobulin >> citrate), in the group with high normal manganese values ("free" Mn >> monomeric form of α2-macroglobulin >> transferring/albumine >> citrate >> tetrameric form of α2-macroglobulin >> dimeric form of α2-macroglobulin). In the group with high normal Mn values relative to the group with low normal values, there was a percentage decrease in the tetrameric fraction of a2-macroglobulin from 17.2 to 4.4%, dimeric fraction of a2-macroglobulin from 6.9 to 2.2%, "free" Mn from 54.3 to 44.4% and an increase in monomeric fraction of a2-macroglobulin from 6.7 to 23.1%, transferrin/albumine from 10.1 to 17.7%, citrate from 4.8 to 8.2%. Our data demonstrate the features of Mn redistribution of dairy cows, which can be used for an extended assessment of the microelement status of animals. [ABSTRACT FROM AUTHOR]

Selenium (Se) is a vital micronutrient with widespread biological action but leads to toxicity when taken in excessive amounts. The biological benefits of Se are mainly derived from its presence in active sites of selenoproteins such as glutathione peroxidase (GPx). An enzyme whose role is to protect tissues against oxidative stress by catalysing the reduction of peroxidase responsible for various forms of cellular damage. The benefits of Se can be harvested when proper regulations of its intake are used. In South Africa, Se distribution in people's diets and animals are low with socio-economic factors and heterogeneous spread of Se in soil throughout the country playing a significant role. The possible causes of low Se in soils may be influenced by underlying geological material, climatic conditions, and anthropogenic activities. Sedimentary rock formations show higher Se concentrations compared to igneous and metamorphic rock formations. Higher Se concentrations in soils dominates in humid and sub-humid areas of South Africa. Furthermore, atmospheric acid deposition dramatically influences the availability of Se to plants. The studies reviewed in this article have shown that atomic absorption spectroscopy (AAS) is the most utilised analytical technique for total Se concentration determination in environmental samples and there is a lack of speciation data for Se concentrations. Shortcomings in Se studies have been identified, and the future research directions of Se in South Africa have been discussed. [ABSTRACT FROM AUTHOR]

Since its inception in the early 80s, inductively coupled plasma–mass spectrometry has developed to the method of choice for the analysis of elements in complex biological systems. High sensitivity paired with isotopic selectivity and a vast dynamic range endorsed ICP-MS for the inquiry of metals in the context of biomedical questions. In a stand-alone configuration, it has optimal qualities for the biomonitoring of major, trace and toxicologically relevant elements and may further be employed for the characterisation of disrupted metabolic pathways in the context of diverse pathologies. The on-line coupling to laser ablation (LA) and chromatography expanded the scope and application range of ICP-MS and set benchmarks for accurate and quantitative speciation analysis and element bioimaging. Furthermore, isotopic analysis provided new avenues to reveal an altered metabolism, for the application of tracers and for calibration approaches. In the last two decades, the scope of ICP-MS was further expanded and inspired by the introduction of new instrumentation and methodologies including novel and improved hardware as well as immunochemical methods. These additions caused a paradigm shift for the biomedical application of ICP-MS and its impact in the medical sciences and enabled the analysis of individual cells, their microenvironment, nanomaterials considered for medical applications, analysis of biomolecules and the design of novel bioassays. These new facets are gradually recognised in the medical communities and several clinical trials are underway. Altogether, ICP-MS emerged as an extremely versatile technique with a vast potential to provide novel insights and complementary perspectives and to push the limits in the medical disciplines. This review will introduce the different facets of ICP-MS and will be divided into two parts. The first part will cover instrumental basics, technological advances, and fundamental considerations as well as traditional and current applications of ICP-MS and its hyphenated techniques in the context of biomonitoring, bioimaging and elemental speciation. The second part will build on this fundament and describe more recent directions with an emphasis on nanomedicine, immunochemistry, mass cytometry and novel bioassays. [ABSTRACT FROM AUTHOR]

A hyphenated instrumental method high-performance liquid chromatography–inductively coupled plasma–optical emission spectrometry (HPLC-ICP-OES) was used for the separation and determination of Cr(III) and Cr(VI). After the chromatographic separation of chromium species by anion exchange column, their spectrophotometric detection was carried out by ICP-OES system. Important instrumental and chromatographic parameters were investigated via univariate optimization approach to obtain high signal to noise ratio and good resolution for chromium species. Under the optimum HPLC-ICP-OES conditions, limit of detection (LOD) values for Cr(III) and Cr(VI) were found to be 0.27 and 0.05 mg/kg, respectively. In addition, accuracy and applicability of developed method were checked by recovery experiments performed with the spiked soil, grass, and water samples. High percent recovery results (88–104%) were achieved by utilizing matrix matching calibration strategy for the selected samples. The results showed that this method was accurate and applicable to soil, grass, and water samples. [ABSTRACT FROM AUTHOR]

A series of sodium polysulfides (SPSs) with different sulfur indexes was prepared as stabilizers to amend elemental mercury-contaminated artisanal small-scale gold mine (ASGM) tailings in Hubei, China, by controlling the molar ratio of sulfur and sodium sulfides as 1:1, 2:1, 3:1, and 4:1 during the synthesis. XRD, XPS, and laser Raman spectroscopy all suggested that the synthesized SPSs were a mixture of multiple polysulfides, sulfur, sodium sulfides, and sodium thiosulfate. Based on toxicity characteristic leaching procedure test (TCLP), mercury stabilization efficiency of SPSs was evaluated and proved to be more superior than sulfur, sodium sulfide, and also calcium polysulfide, with an optimal stabilization efficiency of 97.16% at SPS/THg = 1:2, SPSs pH = initial pH, and liquid-to-solid ratio = 20:7. A pseudo-second-order kinetic model was able to interpret the stabilization kinetics and demonstrated that mercury stabilization rate increased with the sulfur index in the SPSs, but excess SPSs were potentially to inhibit the precipitation of mercury. Speciation analysis results determined with sequential extraction indicated that the unstable mercury, elemental mercury, and organic-bound mercury fractions decreased respectively by up to 88.6%, 53.5%, and 26.3%. Pearson correlation analysis showed that the mercury stabilization in the mine tailings amended with SPSs mainly occurs from the precipitation of the elemental mercury, and the organic mercury fraction reduction was correlated with the decrease of the unstable mercury. [ABSTRACT FROM AUTHOR]

This study showed that the model groundwater containing As3+ and As5+ species was successfully treated with electrocoagulation (EC) first time in the literature investigating toxicity reduction, inorganic arsenic species and detailed sludge characterization. The arsenic removal from model groundwater with 1000 µg/l total arsenic containing equal arsenite (As3+) and arsenate (As5+) concentration was examined by the EC treatment optimized with following parameters; current density (5.0, 7.5 and 10.0 mA/cm2) supporting sodium sulfate electrolyte amount (10, 20 and 30 mM Na2SO4) and initial water pH (3, 6 and 9). In EC treatment, the 99.87% arsenic removal was obtained with 10 mA/cm2, 10 mM Na2SO4 at pH 3 after 40 min supplying 1.44 μg/l effluent As concentration lower than the WHO limit for drinking water. Through transformation mechanisms of more toxic As3+ to less toxic and easily settled As5+ according to As speciation analysis, the toxicity of the model groundwater was successfully decreased in parallel with total arsenic, As3+ and As5+ removal during EC. The precipitated Al(OH)3 and Al2O3 coagulants were the main peaks in the FTIR-ATR spectrum as well as As(III)–O vibration observed between 717 and 721 cm−1 peaks and As(V)–O vibration dominated 899 and 972 cm−1 peaks were detected in the produced sludge after the EC. The SEM–EDS morphological analysis was demonstrated that the sludge was consisted of mostly amorphous structure aggregated size range of 200 μm–2 mm, relatively uniform cake including O, Al, As, Na, and S. [ABSTRACT FROM AUTHOR]

Coal-seam fire is a source of atmospheric mercury that is difficult to control. The Wuda Coalfield in Inner Mongolia, China, is one of the most severe coal fire disaster areas worldwide and has been burning for more than 50 years. To investigate atmospheric mercury pollution from the Wuda coal fire, gaseous elemental mercury (GEM) concentrations and atmospheric particulate mercury (PHg) speciation were measured using a RA-915+ mercury analyzer and the temperature-programmed desorption method. Near-surface GEM concentrations in the Wuda Coalfield and adjacent urban area were 80 ng m−3 (65–90 ng m−3) and 52 ng m−3 (25–95 ng m−3), respectively, which are far higher than the local background value (22 ng m−3). PHg concentrations in the coalfield and urban area also reached significantly high levels, 33 ng m−3 (25–45 ng m−3) and 22 ng m−3 (14–29 ng m−3), respectively (p < 0.05). There is no clear evidence that PHg combines with organic carbon or elemental carbon, but PHg concentration appears to be controlled by air acidity. PHg mainly exists in inorganic forms, such as HgCl2, HgS, HgO, and Hg(NO3)2·H2O. This work can provide references for the speciation analysis of atmospheric PHg and the safety assessment of environmental mercury. [ABSTRACT FROM AUTHOR]

The amyloid β peptide, as one of the main components in senile plaque, represents a defining pathological feature for Alzheimer's disease, and is therefore commonly used as a biomarker for this disease in clinical analysis. However, the selection of suitable standards is limited here, since only a few are commercially available, and these suffer from varying purity. Hence, the accurate characterization of these standards is of great importance. In this study, we developed a method for the traceable quantification of the peptide content using species-specific isotope dilution and ICP-MS/MS detection. It is based on the separation of the sulfur-containing amino acids methionine and cysteine after oxidation and hydrolysis of the peptide. Using a strong anion exchange column, both amino acids could be separated from each other, as well as from their oxidized forms and sulfate. The sulfur content was determined via ICP-MS/MS using oxygen as reaction gas. Species-specific isotope dilution was enabled by using a 34S-labeled yeast hydrolysate, containing methionine sulfone and cysteic acid with different isotopic composition. The peptide contents of Aβ standards (Aβ40,42), as well as myoglobin and lysozyme with different degrees of purity, were determined. For validation purposes, the standard reference material NIST 2389a, which contains the amino acids in a similar concentration, was subjected to the developed sample preparation and analysis method. In addition to accounting for errors during sample preparation, high levels of accuracy and precision could be obtained using this method, making it fit-for-purpose for the characterization of peptide standards. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate the impact of iron deficiency and iron replenishment on serum iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) speciation and tissue accumulation in a deferrioxamine-induced model of iron deficiency. A total of 26 male Wistar rats were divided into three groups: control; Fe-deficient; Fe-replenished (with iron (II) gluconate). Serum ferritin and transferrin levels were assessed using immunoturbudimetric method. Liver, spleen, and serum metal levels were assessed using ICP-MS. Speciation analysis was performed using a hyphenated HPLC-ICP-MS technique. Desferrioxamine injections resulted in a significant decrease in tissue iron content that was reversed by Fe supplementation. Iron speciation revealed a significant increase in serum transferrin-bound iron and reduced ferritin-bound Fe levels. Serum but not tissue Cu levels were characterized by a significant decrease in hypoferremic rats, whereas ceruloplasmin-bound fraction tended to increase. At the same time, Zn levels were found to be higher in liver, spleen, and serum of Fe-deficient rats with a predominant increase in low molecular weight fraction.Both iron-deficient and iron-replenished rats were characteirzed by increased transferrin-bound Mn levels and reduced low-molecular weight fraction. Hypothetically, these differences may be associated with impaired Fe metabolism under Fe-deficient conditions predisposing to impairment of essential metal handling. However, further studies aimed at assessment of the impact on Fe deficiency on metal metabolism are highly required. [ABSTRACT FROM AUTHOR]

The solidification/stabilization (S/S) method is a common technique for the remediation of soils polluted by heavy metal. This study, thus, evaluated the long-term effectiveness, in term of the stabilization of lead in the solidified/stabilized soils, under freeze-thaw cycles, which are important physical processes that lead to material weathering. Three types of compound binders were obtained by mixing the three most commonly used binders (cement, quicklime, and fly ash) in varying proportions for the remediation of lead-contaminated soils. The leachability, chemical forms, and microstructure characteristics of the solidified/stabilized samples after various numbers freeze-thaw cycles (i.e., 0, 30, 90, and 180 times) were examined by utilizing the toxicity characteristic leaching procedure (TCLP) test, chemical speciation analysis, and scanning electron microscopy (SEM). The results showed that the long-term freeze-thaw cycles lead to decreased leachate pH and increased lead concentration in the leachate. The larger the total mix quantities of cement and quicklime, the lower the concentration of lead was presented in the leachate, however, indicating that cement and quicklime are more effective in immobilizing lead ions than fly ash. Chemical speciation analysis revealed that the long-term freeze-thaw cycles did, however, reduce the content of carbonate-bound form lead while the quantity of the ion-exchange forms. SEM further confirmed the observed leaching characteristics and chemical speciation characteristics. In addition, it indicated that, at the same number of freeze-thaw cycles, high initial lead concentrations substantially delayed the hydration process of cement in solidified lead-contaminated soil. [ABSTRACT FROM AUTHOR]

Organoarsenic species in marine matrices have been studied for many years but knowledge gaps still exist. Most literature focuses on monitoring of arsenic (As) species using previously published methods based on anion- and cation-exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). These studies are often limited to few As species and/or only specific method performance characteristics are described. Most marine certified reference materials (CRMs) are only certified for arsenobetaine (AB) and dimethylarsinate (DMA), making it difficult to evaluate the accuracy of analytical methods for other organoarsenic species. To address these gaps, the main objective of this work was to develop and validate a method for speciation analysis of a broad range of organoarsenic species in marine matrices. Optimum extraction conditions were identified through a 27–3 fractional factorial design using blue mussel as test sample. The effects of sample weight, type and volume of extraction solution, addition of H2O2 to the extraction solution, extraction time and temperature, and use of ultrasonication were investigated. The highest As recoveries were obtained by using 0.2 g as sample weight, 5 mL of aqueous methanol (MeOH:H2O, 50% v/v) as extractant, extraction carried out at 90 °C for 30 min, and without ultrasonication. Anion- and cation-exchange HPLC-ICP-MS settings were subsequently optimized. The method detected a total of 33 known and unknown As species within a run time of 23 and 20 min for cation-exchange and anion-exchange, respectively. A single-laboratory validation was conducted using several marine CRMs: BCR 627 (tuna fish tissue), ERM-CE278k (mussel tissue), DORM-4 (fish protein), DOLT-5 (dogfish liver), SQID-1 (cuttlefish), TORT-3 (lobster hepatopancreas), and CRM 7405-b (hijiki seaweed). Method performance characteristics were evaluated based on selectivity, limits of detection and quantification, linearity, trueness, precision, and measurement uncertainty. This work proposes an extraction procedure which allowed satisfactory quantification of As species with low solvent and energy consumption, supporting "Green Chemistry" principles. The study also presents a new set of As speciation data, including methylated arsenic species and arsenosugars, in recently issued marine CRMs, which will be valuable for future speciation studies on As. This work is the first to report a total of 33 different As species in marine CRMs. [ABSTRACT FROM AUTHOR]

This study investigated the mobility and availability of Cd, Pb, and As pollution in the sediments of the Xijiang River Basin, China. The speciation analysis and ecological risk assessment of Cd, Pb, As in 21 sediment samples from the Xijiang River basin were studied by the sequential extraction technique, the enrichment factor (EF), the geo-accumulation index (Igeo), the potential ecological risk index (RI), the potential ecological risk factor (Eri), the risk assessment code (RAC), and the modified potential ecological risk index (MRI) assessment method. Metal speciation analysis indicated that the exchangeable and carbonate fraction were the primary binding phase for Cd in the sediment. However, the residual fraction was the major host for Pb and As. The Cd, Pb, and As speciation were highly correlated with Mn, organic matter (OM), carbonate (Carb), and pH. The RAC and MRI results showed that the mobility and availability of Cd, Pb, and As in the sediment followed the order of Cd > As > Pb. The higher mobility of Cd posed an elevated environmental risk. Moreover, it was found that the Diaojiang River had high ecological risk levels. Principal component analysis (PCA) and redundancy analysis (RDA) revealed that the mining industry mainly contributed to the enrichment of Cd, Pb, and As. This study provides a better understanding to predict and possibly find ways to control pollution of Cd, Pb, and As in sediments of such basins. [ABSTRACT FROM AUTHOR]

Time-dependent density functional theory (TD-DFT) and spectrophotometric methods were used for speciation analysis in systems disulfides (cystine, cystamine, homocystine, 3,3-dithiodipropionic acid) — [PdCl4]2− or [PtCl4]2−. We use the M06-2X and CAM-B3LYP density functionals with Def2-SVP basis set to reproduce the experimental UV-vis spectra; the polarized continuum solvation model (PCM) was fitted to take into account solvation effects of the medium (water). Used methods have shown the good agrees with the experiment — theoretical values of transition energies differ from real parameters within ±0.15 eV for functional CAM-B3LYP. Binuclear disulfide complexes of Pd(II) with cystine and cystamine have form S,N-coordination sites, instead of S,S-conformation. It was shown that Pd(II) thiolate complexes formed by cleavage of the disulfide bond exist as [PdCl3L] and [Pd2S2L2]. Pt(II)-disulfide systems have confirmed the presence of [Pt2Cl6(R-SS-R)] and [PtCl4(S-R)] complex species. The DFT/CAM-B3LYP/Def2-SVP/SMD level can be recommended for theoretical estimations of absorption spectra of complexes of palladium or platinum and sulfur-containing ligands. [ABSTRACT FROM AUTHOR]

The occurrence of 21 trace elements in native Mediterranean mussel (Mytilus galloprovincialis) from the Calich Lagoon, a typical brackish area of the northwest of Sardinia (Italy), was investigated. The seasonal variation of metals in bivalves was considered, and the highest values were found in spring and summer; in particular, a high significant (P < 0.001) temporal variation was reported for silver (Ag) and mercury (Hg). The highest and similar concentrations were registered for aluminium (Al, mean 32 mg kg−1wet weight), iron (Fe, mean 32 mg kg−1 w. w.), and zinc (Zn, mean 25 mg kg−1 w. w.). The maximum limits set by European Regulations for cadmium (Cd), mercury (Hg), and lead (Pb) were never exceeded. Speciation analysis revealed negligible risk related to inorganic arsenic (iAs). Therefore, M. galloprovincialis confirmed its role as suitable bioindicator to monitor the contamination of coastal environments. Although the recommended tolerable weekly intake (TWI) was not exceeded, the levels of aluminium should be carefully evaluated in monitoring plans in the studied lagoon. [ABSTRACT FROM AUTHOR]

A fast, efficient, and non-chromatographic method was presented in this study for nitrite, nitrate, and p-nitrophenol (N-compounds) extraction and speciation analysis of environmental samples. By applying ultrasound-assisted solid–liquid extraction (USLE), analytes were efficiently extracted from water, soil, or sediment collected in areas of environmental disaster. These analytes were selectively converted to NO(g) through UV photolysis (NO3−), H2O2/UV photocatalysis (PNP), and direct conversion (NO2−). Following conversion, NO(g) was separated from the liquid phase and determined by high-resolution continuum source molecular absorption spectrometry (HR-CS MAS). The LODs obtained were 0.097 ± 0.004 mg L−1 for nitrite, 0.119 ± 0.004 mg L−1 for nitrate, and 0.090 ± 0.006 mg L−1 for p-nitrophenol. On applying this speciation method to environmental samples, concentrations were found to be up to 0.99 ± 0.03 mg L−1 (NO2−), 49.80 ± 2.5 mg L−1 (NO3−), and 0.10 ± 0.02 mg L−1 (PNP). Finally, addition/recovery study of real water, soil, and sediment samples showed 101 ± 2% recovery for NO2−, 100 ± 1% for NO3−, and 96 ± 5% for PNP. [ABSTRACT FROM AUTHOR]

The total contents and chemical speciation analysis of Zn, Cu, Pb, Cr, Mn, Ni, Cd, and As in pig manure (PM), liquefaction residues (LRs), and bio-oils (BOs) derived from PM by liquefaction with ethanol as a solvent at 180–300 °C were thoroughly investigated in this study. The environment risk assessment, leachability, and bioavailability of heavy metals in PM and LRs were studied. The results showed that more than 75% of heavy metals remained in LRs. The total contents of heavy metals in LRs were markedly elevated, but those in BOs gradually decreased with the increase in liquefaction temperature. Moreover, the acid soluble/exchangeable fraction and reducible fraction (F1 + F2) of heavy metals in LRs and BOs was significantly reduced, while oxidizable fraction and stable fraction (F3 + F4) desirably increased after liquefaction. Furthermore, the potential risk of heavy metals in LRs was decreased in comparison to that in PM, but the risk of Pb, Mn, and As had not been obviously reduced; therefore, the LRs from the liquefaction of PM should be pretreated before recycling. Temperatures from 220 to 260 °C were the optimum conditions for disposing of PM by liquefaction with ethanol. [ABSTRACT FROM AUTHOR]

In this study, famous Zhejiang teas were evaluated as a well-advertised source of selenium. The 25 samples from provinces around China and Asia were purchased in Warsaw tea shops. The speciation analysis of selenium as well as the evaluation of catechin content in water tea infusions was performed using hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS/MS). It turned out that all of tested samples can be a great source of organic selenium species (no traces of inorganic selenium was found), however, Zhejiang teas did not differ much among others. Such a conclusion can also be drawn when comparing the antioxidant capacity of the tested samples, obtained with the application of four methods (Folin–Ciocalteu method, scavenging of the 2,2-diphenyl-1-picrylhydrazyl radical, hydroxyl radical scavenging and cupric reducing ability assay). What is more, no correlation was found between the selenium content and the antioxidant activity of studied teas. The results obtained for the six samples from Zhejiang Province were very varied, which shows that it is very difficult to interpret the results and compare them with the results of other authors. [ABSTRACT FROM AUTHOR]

This work represents the first systematic speciation study of selenium (Se) in plasma from subjects participating in a pilot study for a cancer prevention trial (PRECISE). This involved supplementation of elderly British and Danish individuals with selenised yeast for 6 months and 5 years, respectively, at 100, 200, and 300 μg Se/day or placebo. Speciation data was obtained for male plasma using HPLC-ICP-MS and HPLC-ESI-MS/MS. With the proposed strategy, approximately 1.5 mL of plasma was needed to determine total Se concentration and the fractionation of Se in high molecular weight (HMW) and low molecular weight (LMW) pools, and for quantification and identification of small Se species. For the first time, Se-methyl-selenocysteine (MSC) and methyl-2-acetamido-2deoxy1-seleno-β-d-galactopyranoside (Selenosugar-1) were structurally confirmed in plasma after supplementation with selenised yeast within the studied range. Determination of selenomethionine (SeMet) incorporated non-specifically into albumin (SeALB) was achieved by HPLC-ICP-MS after hydrolysis. By subtracting this SeMet concentration from the total Se in the HMW pool, the concentration of Se incorporated into selenoproteins was calculated. Results from the speciation analysis of the free Se metabolite fraction (5% of total plasma Se) suggest a significant increase in the percentage of Se (as SeMet plus Selenosugar-1) of up to 80% of the total Se in the LMW fraction after 6 months of supplementation. The Se distribution in the HMW fraction reflects a significant increase in SeALB with Se depletion from selenoproteins, which occurs most significantly at doses of over 100 μg Se/day after 5 years. The results of this work will inform future trial design. [ABSTRACT FROM AUTHOR]

A sensitive and selective fluorescent nitrogen-doped carbon dots (N-CDs) probe was synthesized by using glucosamine as a single reagent in a one-step hydrothermal treatment and was also characterized by UV-Vis spectrophotometer, fluorescence spectrophotometer, transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectrometer, X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS). N-CDs exhibited a superior water solubility and an excellent fluorescence characteristic and was used as a fluorophore to measure ClO− and NO2− based on their oxidation in the presence of Fe2+. The quenching mechanism of ClO− and NO2− to the system probe of Fe2+@N-CDs was also demonstrated. The detection limit of the probe to ClO− was 0.75 μM in the linear range of 1 to 17.5 μM and for NO2− was 0.85 μM with the linear range of 2.5 to 20 μM. Speciation analysis of ClO− and NO2− could be distinguished due to the different reactive response time to the system probe of Fe2+@N-CDs, and the accuracy was further confirmed by detecting them in actual river water and tap water samples. [ABSTRACT FROM AUTHOR]

This review covers the investigations carried out with my colleagues and students during the last 25 years aimed at the development of analytical procedures for the preconcentration and/or speciation analysis of trace and ultra-trace elements using bio- and nanosorbents employing different methodologies, analytical techniques, and instrumental approaches. In the last years, an important part of this research was based on the use of nanomaterials for preconcentration and/or speciation studies. For their properties, they constitute a break point in the evolution of analytical chemistry. Special attention was paid to carbon nanotubes (CNTs) that resulted effective sorbents in flow systems using different immobilization strategies to improve their sorption capabilities. They resulted unique tools for on-line solid-phase (micro)extraction methods providing the appropriate selectivity (clean-up) and sensitivity (preconcentration) to reach the expected levels of many elements in matrices of biological or environmental interest. The performance of the different substrates, their strengths and weaknesses for the determination of trace elements, and their species in different matrices by a variety of analytical techniques are discussed in detail, along with perspectives and possible challenges in future development. This survey contains 96 references and covers primarily the literature published over the last 25 years by our research group. Relevant publications on the topics discussed were also included. [ABSTRACT FROM AUTHOR]

Experiments conducted over a period of 6 weeks using Brassica napus callus cells grown in vitro under Eu(III) or U(VI) stress showed that B. napus cells were able to bioassociate both potentially toxic metals (PTM), 628 nmol Eu/gfresh cells and 995 nmol U/gfresh cells. Most of the Eu(III) and U(VI) was found to be enriched in the cell wall fraction. Under high metal stress (200 μM), cells responded with reduced cell viability and growth. Subsequent speciation analyses using both metals as luminescence probes confirmed that B. napus callus cells provided multiple-binding environments for Eu(III) and U(VI). Moreover, two different inner-sphere Eu3+ species could be distinguished. For U(VI), a dominant binding by organic and/or inorganic phosphate groups of the plant biomass can be concluded. [ABSTRACT FROM AUTHOR]

In this work, a methodology for chemical speciation analysis of inorganic As and Sb in urban dust using slurry sampling and detection by fast sequential hydride generation atomic absorption spectrometry is proposed. Doehlert design and desirability function were used to find the optimum conditions for hydride generation (1.0 mol L−1 HCl and 0.9% m v−1 NaBH4). The accuracy of the analytical method was evaluated by analysis of reference material fly ash (BCR 176R), addition and recovery tests for inorganic As species, and comparison of independent methods for Sb determination in urban dust samples. The determination of the total concentrations of As and Sb and their inorganic species presented good accuracy, between 80 ± 1 and 101 ± 6%. Precision was expressed as the relative standard deviation and was better than 4.7% (n = 3). The limit-of-quantification values were 0.23 and 1.03 mg kg−1 for As and Sb, respectively. The methodology was applied to eight samples of dust collected in an urban area of Salvador and Jaguaquara cities, Bahia, Northeast, Brazil, with an aerodynamic size lower than 38 μm. Concentrations of pentavalent inorganic species (iAs5+ and iSb5+) in relation to trivalent species (iAs3+ and iSb3+) were found in urban dust collected in the city of Salvador, which are regarded as more toxic for both elements. The enrichment factor and geoaccumulation index (Igeo) values showed that for some samples, the concentrations of iAs and iSb presented strong enrichment and, and regarding environment, strong to moderately polluted by iAs and iSb, with an indication of anthropogenic contributions. The occurrence of these inorganic constituents in the urban area of Salvador can be related with intense industrial activities and vehicular traffic. [ABSTRACT FROM AUTHOR]

Arsenic contamination of the groundwater in the Hetao area in Inner Mongolia, China, has been a serious problem since the 1980s. In this study, the behavioral mechanics of arsenic in soil in the Hetao area, in relation to arsenic concentrations in groundwater, were studied using elemental speciation analysis. It is for probing the possible mechanisms of correlation and interaction within water and soil of the area, which is little work on it not only in the Hetao area but also worldwide. Associated with our previous work on water in this area, soil samples were collected along transects through areas strongly affected by arsenic poisoning. Sequential extractions were used to determine the speciation in soil of arsenic and other elements (Cd, Cu, Mo, Pb, Sb, Sn, and Zn) which are with similar geochemical behaviors to arsenic in natural systems. The results show that the arsenic concentration in soil is correlated with arsenic concentration in groundwater. This implies that arsenic transformation as a main factor of the resident poisoning of the area could be related with groundwater and soil. These results suggest that arsenic poisoning in the Hetao area is related with water and soil. The tracers moving through water are retained in the shallow stratum including soil and persist in the water affected by the movement of arsenic through the shallow stratum and soil. [ABSTRACT FROM AUTHOR]

Wild edible mushrooms can accumulate significantly elevated levels of mercury from the surrounding environment, which could be harmful to consumers' health. Speciation analysis of mercury in wild edible mushrooms aids in understanding the human exposure to these toxic compounds. In this study, we developed a high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) method for the simultaneous determination of inorganic mercury (Hg(II)), methylmercury (MeHg), ethylmercury (EtHg), and phenylmercury (PhHg) in wild edible mushrooms. A rapid separation of four target mercury species was achieved within 11 min by a C8 column without utilizing high proportion of organic phase in HPLC. The parameters affecting the extraction efficiency of mercury in samples have been investigated. The proposed method showed good linearity within 0–50 μg/L with the detection and quantification limits of 0.6–4.5 μg/kg (S/N = 3), and 2.0–15 μg/kg (S/N = 10), respectively. This proposed method was successfully applied to the mercury speciation analysis in 7 varieties (95 samples) of wild edible mushrooms. The results indicated that in most mushroom samples, mercury mainly occurred as inorganic mercury. But there were two Tricholoma matsutakes, one contained 0.14 mg/kg of methylmercury, another contained 1.05 mg/kg of phenylmercury, which were higher than the maximum allowable content of total mercury in edible mushrooms in China. [ABSTRACT FROM AUTHOR]

Nickel-contaminated soil was treated by adding different amounts of calcium oxide in this study. The leaching concentration, pH, and bioavailability of the soil samples were investigated on the 3rd, 6th, 9th, 12th, and 15th days. The chemical speciation changes of the contaminated soil treated with calcium oxide were analyzed, and the soil phases were analyzed by X-ray diffraction (XRD). Results showed that the application of calcium oxide increased the pH of the soil, resulting in passivation of nickel ions in soil by forming a poorly soluble precipitate. It was identified that addition of 5% of calcium oxide showed the best result, with the leaching concentration on the third day reaching 0.35 mg/L, which is 99.21% lower than the untreated soil's leaching concentration of 44.24 mg/L. On the 15th day, the bioavailability of nickel decreased from the untreated soil's 93.82 to 36.73%. It was also observed that the pH of the soil increased at the beginning and decreased afterwards. The pH value was 7.94 on the 15th day. In addition, the water-soluble fraction of Ni decreased from 7.39 without treatment to 0.19%; the reducible fraction of Ni decreased from 35.14 to 25.79%, and the oxidizable fraction of Ni increased from 10.37 to 29.10%, respectively, on the 15th day after the treatment with calcium oxide. XRD analysis of soil samples showed the amorphous nickel hydroxide may be formed in the precipitation process. [ABSTRACT FROM AUTHOR]

The poly amino acid ionic liquid (poly-1-vinyl-3-butylimidazolium glutamate acid, p-1-VbmGlu), with a stable up-conversion fluorescence(UCF) probe, was firstly prepared and the synthesis conditions were optimized. The UCF were found to be specifically quenched by Fe(III), but not respond to Fe(II). In H2O2 medium, Fe(II) posed strong quenching effect on the UFC owing to Fe(III) produced by redox between H2O2.and Fe(II). Therefore p-1-VbmGlu was employed as a UFC for Fe(II)/Fe(III) speciation analysis under the control of H2O2. The detection limits of Fe(II)/Fe(III) were 6.16 ng/mL and 4.48 ng/mL, with relative standard deviations of 1.1% and 2.0%, respectively. This method was successfully utilized in the analysis of Fe(II)/Fe(III) in multiple real samples. [ABSTRACT FROM AUTHOR]

Purpose: Vanadium (V) contamination in soil can cause diverse damage to soil ecosystem and has attracted research interests in exploring soil V stabilization methods, but only a few materials were proposed and studied. Here, a pot experiment was firstly conducted to estimate the efficiency of nano-hydroxyapatite (n-HAP) in stabilizing V in soil. To verify the impact of n-HAP on soil V bioavailability and phytotoxicity, cabbages (Brassica chinensis L.) were grown in V-spiked soils after n-HAP amendment. Materials and methods: Soils were sampled from a farmland in China, and the n-HAP was prepared in the laboratory. In each pot of soil spiked with 0, 75, 150, 300, and 600 mg/kg V, 2% n-HAP was amended for 30 days, while soils without n-HAP amendment were set as controls. The stabilization effect of n-HAP on V in soil was estimated by the water-extractable and bioavailable V concentrations in soils. Cabbages were grown in pots subsequently. The V(V/IV) concentrations in cabbage leaves and roots, the organic bound V concentrations in cabbage roots, and the chlorophyll concentrations in leaves were determined. Bioconcentration factor and translocation factor were calculated. The composition of organic bound V in leaf was characterized by fluorescence excitation–emission matrix. Results and discussion: In soils spiked with 150 mg/kg V, n-HAP amendment yielded the highest stabilization rates of 51.0% and 42.4% for water-extractable and bioavailable V, respectively. In 75, 150, and 300 mg/kg V-spiked soil, the plant weight, plant height, and root length of cabbage after 60-day growing decreased 54.6%/89.6%, 30.9%/45.5%, and 41.5%/51.4% in groups with/without n-HAP, respectively. Cabbage leaf chlorophyll concentrations descend firstly then ascend with rising soil V concentration. Leaf V speciation analysis revealed that less leaf V was reduced to V(IV) in groups amended with n-HAP than groups without n-HAP amendment. In 150 and 300 mg/kg V-spiked soil, n-HAP effectively reduced the V content and the V bioconcentration factor of cabbage root. Tyrosine-like and humic acid-like analogues composed the principal part of V complex. Conclusions: In general, n-HAP amendments are potential to decrease the mobility of V in soils, as well as inhibit the bioavailability and phytotoxicity of V to cabbage. In V-spiked soils, n-HAP amendment can alleviate the toxicity of V to the cabbage. Overall, 2% n-HAP is efficient for the amendment of slight V-polluted (150–300 mg/kg) soils to alleviate the soil V stress to cabbage. [ABSTRACT FROM AUTHOR]

Determination of long-lived radionuclides is critical for environmental radioactivity investigation, environmental processes studies and decommissioning of nuclear facilities. This paper summarizes main progress in the radiochemical analysis in our laboratories in the past years for determination of ultra-low level radionuclides in the environment using chemical separation combined with mass spectrometry measurement. The analytical methods for determination of ultra-low level 129I and its chemical species in various environmental samples are highlighted. The methods developed in our laboratories for characterization of decommissioning waste, especially the methods for the determination of difficult-to-measure radionuclides using sequentially chemical separation and radiometric measurement are also briefly presented. This is also a part of the Hevesy Medal award lecture in the RANC2019 conference. [ABSTRACT FROM AUTHOR]

Purpose: River sediment pollution by heavy metals/metalloids has attracted widespread attention due to a serious threat to the ecosystem and human health. As an effective and economical alternative, the stabilization method was considered by previous studies for the remediation of sediments polluted by metals/metalloids. However, a comprehensive study is required for an extensive comparison on the effects of metal/metalloid immobilization based on the application of different materials as sediment amendments. Materials and methods: In this study, the Maozhou River was selected as the study area, and the stabilization method was applied for the remediation of the river sediment polluted by metals and metalloids. Five materials (CaCO3, Ca(OH)2, zeolite, kaolin, FeCl2) were selected as amendments for the metal/metalloid stabilization in the collected sediment. A modified BCR procedure was employed for the speciation analysis of heavy metals and metalloid in the sediment before and after remediation. A TCLP (toxicity characteristic leaching procedure) investigation was performed to further evaluate the immobilization of heavy metals in acidic environment. Results and discussion: The sediment of the Maozhou River was heavily polluted by heavy metals and metalloid. The speciation of As, Pb, Cr, and Mn mainly exists as residual fraction (F4), while that of Ni, Cu, and Zn was identified as exchangeable metal and carbonate-associated fraction (F1) and fraction associated with Fe-Mn oxides (F2). Moreover, the F2 fraction of Co was observed as the major speciation. Through the application of five materials (CaCO3, Ca(OH)2, zeolite, kaolin, FeCl2) as sediment amendments, the metal/metalloid speciation was transferred into F4. When five amendments were compared, the stabilization effect can be ordered as CaCO3 > zeolite > FeCl2 > kaolin > Ca(OH)2 based on the modified BCR results. TCLP results showed that using Ca(OH)2 and CaCO3 as amendments can significantly reduce the metal leachability in an acidic environment, while zeolite is effective for most of the heavy metals and metalloid. Conclusions: The results showed that the sediment of the Maozhou River was seriously polluted by a variety of heavy metals and metalloids. This study provided extensive information on the speciation of metals or metalloid and the effect of various amendments on metals and metalloid stabilization, which can be of vital importance for further remediation of metal/metalloid-polluted sediment. [ABSTRACT FROM AUTHOR]

In the recent decade, metal pyrithione complexes have become important biocides for antifouling purposes in shipping. The analysis of metal pyrithione complexes and their degradation products/species in environmental samples is challenging because they exhibit fast UV degradation, transmetalation, and ligand substitution and are known to be prone to spontaneous species transformation within a chromatographic system. The environmental properties of the pyrithione species, e.g., toxicity to target and non-target organisms, are differing strongly, and it is therefore inevitable to identify as well as quantify all species separately. To cope with the separation of metal pyrithione species with minimum species transformation during analysis, a capillary electrophoresis (CE)–based method was developed. The hyphenation of CE with selective electrospray ionization- and inductively coupled plasma–mass spectrometry (ESI-, ICP-MS) provided complementary molecular and elemental information for the identification and quantification of pyrithione species. To study speciation of pyrithiones, a leaching experiment of several commercial antifouling paints containing zinc pyrithione in ultrapure and river water was conducted. Only the two species pyrithione (HPT) and dipyrithione ((PT)2) were found in the leaching media, in concentrations between 0.086 and 2.4 μM (HPT) and between 0.062 and 0.59 μM ((PT)2), depending on the paint and leaching medium. The limits of detection were 20 nM (HPT) and 10 nM ((PT)2). The results show that complementary CE-MS is a suitable tool for mechanistical studies concerning species transformation (e.g., degradation) and the identification of target species of metal pyrithione complexes in real surface water matrices, laying the ground for future environmental studies. [ABSTRACT FROM AUTHOR]

Chloride widely exists in the environment and will cause serious interference for arsenic speciation analysis. The determination of four arsenic species including arsenite (As(III)), arsenate (As(V)), monomethylarsenate (MMA), and dimethylarsonate (DMA) in samples containing high concentrations of Cl− was carried out in this work by coupling of liquid chromatography (LC) with hydride generation atomic fluorescence spectrometry (HG-AFS). The interference of Cl− was successfully eliminated by coupling two anion-exchange chromatographic columns in series and eluting with 35.0 mmol L−1 (NH4)2HPO4 (pH = 6.00). A novel pre-treatment system was subsequently developed to realize on-line column switch and pre-reduction of As(V). The analysis time was shortened by an isocratic elution but programmed flow rate method, and the sensitivity of As(V) was also enhanced by the introduction of pre-reduction using the developed system. The proposed method can resist at least 10 g L−1 Cl− without any pre-treatment operations. Since LC-HG-AFS is low-cost and can be afforded or self-assembled by most labs, the developed method can be adopted as a routine analysis method for arsenic species in chloride-bearing samples, such as urine and seawater. [ABSTRACT FROM AUTHOR]

The total uranium (U) content and various forms of U content in the farmland-paddy rice system around uranium tailings dam were investigated and analyzed to reveal the actual situation of U pollution and its influencing factors. The results showed that the U content in the study area was not high overall and mainly existed in the form of residual state, so the actual contamination degree of U was low. Soil physicochemical properties had different effects on U content in soil and rice. The research results were of positive significance for guiding the treatment of U pollution in this region. [ABSTRACT FROM AUTHOR]

The concentrations of six metals (Zn, Cu, Pb, Ni, Cr, and Cd) were investigated in bottom sediments of Straszyn Lake (North Poland). This study was designed to determine a total content of metals and to assess their mobility and bioavailability. The sequential extraction was used to fractionate metals into five fractions: exchangeable, bound to carbonates, bound to Fe–Mn oxides, bound to organic matter, and residual. The evaluation of sediments contamination degree by metals was performed by applying the geochemical quality guidelines, the pollution load index, and the geo-accumulation index (Igeo). The assessment based on these methods demonstrated that sediments were polluted with Cr and the sediments quality guidelines confirmed these results. Moreover, the average concentrations of Cu, Ni, and Cr were respectively 3.4, 3.9, and 21.2 times higher than their background values. According to ecological risk index and risk assessment code Cd was the most important factor affecting the ecological environment of the Straszyn Lake. The metal speciation analysis demonstrated that the mean percentage of metals in the exchangeable and carbonate fractions decreased in the following order: Cd (59.1%) > Zn (19.8%) = Ni (19.8%) > Pb (16.6%) > Cu (3.3%) > Cr (2.7%). The very strong correlation calculated between all the metals indicated their common origin. [ABSTRACT FROM AUTHOR]