Total Sb Concentrations Research Articles

The Nutritional Value of Plant Drink against Bovine Milk—Analysis of the Total Concentrations and the Bio-Accessible Fraction of Elements in Cow Milk and Plant-Based Beverages

Four types of non-dairy (plant) drinks—almond, oat, rice, and soy—as well as cow milk with varying fat contents (1.5%, 2.0%, and 3.2%), were examined and compared in terms of the total concentrations of Al, As, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Mn, Ni, P, Pb, Sb, Se, Sr, and Zn using inductively coupled optical emission spectrometry (ICP OES). Additionally, in vitro gastrointestinal digestion was used to determine the bio-accessible fraction of selected elements, evaluating the nutritional value and risk assessment involved with the consumption of these beverages. A significant difference in the mineral profile was observed depending on the type of plant drink, with the highest content of elements noted in the soy drink and the lowest in the rice drink. Except for Ca and P, the soy drink appears to be a much better source of essential nutrients, including Cu, Fe, and Mn, than cow’s milk. A similar Ca content in plant beverages can be obtained only by adding calcium salt at the stage of its production. Interestingly, by using the multivariate data analysis, the average content of the selected elements (Cu, K, Na, P, and Zn) can be used both to differentiate dairy and non-dairy milk samples according to their type and to distinguish plant drinks from milk of animal origin. The bio-accessibility of essential elements (Ca, Cu, Fe, Mg, Mn, P, Zn) in cow milk was within 8.37–98.2% and increased with an increase in its fat content. Accordingly, by drinking 1 L of this milk daily, it is possible to contribute to the recommended dietary intakes of Ca, P, Cu, Mg, and Zn between 5.6–68%. Although the bio-accessibility of elements in the rice drink was the highest (9.0–90.8%), the soy drink seems to be the best source of nutrients in bioavailable forms; its consumption (1 L/day) covers the requirements of Cu, Mn, Mg, Ca, P, and Zn in 7.0–67%. Unfortunately, both groups of beverages are not important sources of Fe (plant drink) and Mn or Fe (cow milk) in the human diet. On the other hand, potentially toxic elements (Al, B, Ba) were found in them in a relatively inert form.

Microbial metabolic activity in metal(loid)s contaminated sites impacted by different non-ferrous metal activities

Many non-ferrous metal mining and smelting activities have caused severe metal(loid) contamination in the local soil environment. The metabolic activity of soil microorganisms in four areas affected by different metallurgical activities (production vs. waste disposal) was characterized using a contamination gradient from the contaminated site to the surrounding soils. Results indicated that the soil microcalorimetric and enzyme activities were correlated with the fractionated metal(loid) properties (p < 0.05). All four areas had high total As, Cd, Pb, Sb, and Zn concentrations, of which mobile As, Cu, Ni, Pb, Sb, and Zn were higher in the contaminated sites than the surrounding sites, reflecting an elevated environmental risk. Three contaminated site areas had lower microbial activities than their surrounding sites suggesting that high metal(loid) concentrations inhibited soil microbial communities. Interestingly, the fourth area (tailing pond) showed an opposite trend (i.e., increased microbial activity in contaminated vs. surrounding areas). The microbial thermodynamic parameters of this contaminated site were higher than its surrounding sites, suggesting that the selected microbial communities can develop a functional resistance to metal(loid)s stress. This study provides a theoretical basis for ecological prevention and control of metal-polluted areas.

Microbial reduction of antimony under anaerobic conditions by inocula from different sources

Antimony (Sb) is a toxic and carcinogenic metalloid that can be present in contaminated water generated by mining operations and other industrial activities. Dissimilatory Sb(V) reduction to Sb(III) under anaerobic conditions by prokaryotic microbial communities has been reported; however, the fate of antimony in anaerobic wastewater treatment systems is poorly understood. This study investigated the potential of six different inoculum sources to reduce Sb(V) under anaerobic conditions and correlated the Sb(V) reduction rate with the microbial community composition. Microbial reduction of Sb(V) to Sb(III) by all the inoculum sources tested was observed in anaerobic incubations using hydrogen as an electron donor after a month. The highest reduction rate observed was 12.5 mg Sb per gram of volatile suspended solids per day. In some inocula, not only Sb reduction was observed, but also a decrease in the total Sb concentration, suggesting the precipitation of Sb(III). Metagenomic analysis revealed high variability in the community diversity associated with the origin of the inoculum. For the family taxonomic category, the three inocula that showed the highest Sb reduction potential were characterized by the presence of the Bacillaceae family.

Human health risks associated with trace metals in dust of residential arid areas

Composite dust samples were collected on a monthly basis over a full year from Doha, Qatar. Inductively Coupled Plasma Mass Spectrometry (ICPMS) was used for the determination of total concentrations of Na, K, Mg, Ca, Li, Be, B, V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Ba, Al, Pb, Ag, TI, U, Sb, Si, Sn, Mo and Bi. A combined approach, merging conventional sampling and analysis with subsequent numerical calculations of the risk of exposure to toxic elements, was employed. For assessment of the health risks associated with the regular exposure to dust, the exposure routes related to the dermal contact and inhalation were considered. Our results indicate that the total non-carcinogenic health risk through exposure to different elements (Hazardous Quotients, HQ's) that are contained in the dust are quite low (well below unity) for both dermal contact and inhalation routes in all months of the year, i.e., there is no risk to the human health. There is no clear explanation for the seasonal variation of metals in the dust in the Qatar area. Several elements in the dust collected in the summertime have higher concentration than in the wintertime. This could be due to the weather conditions and natural depositions. However, the content of several elements (Pb, Zn, Cu, Sn and Li) showed elevation in the wintertime. For dermal exposure, the dominant contribution to the Hazardous Index (HI) comes from thallium (Tl) while for inhalation exposure several comparable contributions are related to Mn, Sb, Si, Ni, and Co. Long-term monitoring strategies are still needed for detailed research on dust pollutants and potential risks.

Effect of iron cyclic transformation on the natural purification of antimony in contaminated reservoirs of mines

To further understand the purification mechanism of antimony (Sb) in reservoirs, samples of stratified water and bottom interface sediment were collected in this study. The cross-flow ultrafiltration technique was used to separate the truly dissolved (<1 kDa) and colloidal (1 kDa–0.45 μm) phases of water, and two modified sequential extraction techniques were used to determine the Sb and Fe mineral forms in sediment, respectively. The results showed that the total Sb concentration could decrease from 142.2 μg/L in surface water to 98.6 μg/L at 16 m; this was contributed to by the removal of truly dissolved Sb. In comparison to particulate Sb (>0.45 μm), the formation of colloidal Sb played a greater role in the purification process. There was a positive correlation between Sb and Fe in the colloidal phase (r = 0.45, P < 0.05). The generation of colloidal Fe could be promoted by higher temperatures, pH values, DO, and DOC in the upper layer (0–5 m). However, the complexation of DOC with colloidal Fe inhibited the adsorption of truly dissolved Sb. After entering the sediment, the secondary release of Sb could not increase the Sb concentration in the lower layer obviously, while the supplementation of Fe(III) could further enhance Sb natural purification.

A simple and green dispersive micro-solid phase extraction method by combined application of graphene oxide and a magnetic ionic liquid for selective determination of inorganic antimony species in water, tea and honey samples

A highly selective and efficient method based on the use of graphene oxide (GO) and a magnetic ionic liquid (MIL) for dispersive micro-solid phase extraction (D-μ-SPE) was developed for inorganic Sb speciation analysis. In this work, Sb(III) species was selectively complexed with sodium diethyldithiocarbamate (DDTC) and retained on 3 mg of GO. Afterwards, 40 μL of the MIL trihexyl(tetradecyl)phosphonium hexachlorodysprosiate(III) ([P6,6,6,14]3DyCl6) were added to instantly magnetize the sorbent surface followed by its separation using a magnetic rod. Then, the aqueous phase containing only Sb(V) was directly analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Total Sb concentration was obtained by direct introduction of the sample into ICP-MS instrument. Thus, Sb(III) was calculated based on the difference between the concentrations of total inorganic Sb and Sb(V). Extraction conditions were optimized by a multivariate study yielding a 99.7% extraction efficiency for Sb(III). Limits of detection of 5 ng L−1 for Sb(III) and 3 ng L−1 for Sb(V) and relative standard deviations of 3.2% for Sb(III) and 2.9% for Sb(V) (at 10 μg L−1 Sb(III) and Sb(V), n = 6) were obtained. The calibration linear range was 0.01–80 μg L−1. The proposed method was successfully applied for separation and determination of inorganic Sb species in tap water, tea infusions and honey samples. Furthermore, the greenness of the D-μ-SPE method was assessed by the use of the Analytical GREEnness calculator (AGREE), obtaining a value of 0.61.

Occurrence, distribution, and migration of antimony in the Zijiang River around a superlarge antimony deposit zone

Under the environmental changes associated with mine tributaries entering mainstream rivers, differences in the distributions and migration behaviors of metal(loid)s can be found, but the behavior of antimony (Sb) is still poorly understood in this regard. We analyzed the occurrence, distribution, migration, and influencing factors of the Sb concentration in the water body of the Zijiang River (ZR) around a superlarge Sb deposit zone. The total Sb concentrations were 1.45–15.66 μg/L, 3.16–133.63 mg/kg, and 0.83–41.82 μg/L in the ZR surface waters, sediments, and pore waters, respectively; Sb(V) was the predominant form of Sb found in the surface waters. Mining and smelting were the main sources of Sb in the ZR. Spatially, the Sb concentration showed a decreasing trend from the tributaries to the ZR mainstream. In the ZR, the surface-water Sb concentration showed an increasing trend from the upstream to the downstream, while in the sediments and pore waters, the midstream Sb concentrations were higher than the upstream and downstream concentrations; this finding was related to the sediment retention and accumulation behaviors of reservoirs and dams resulting in the secondary release of Sb in sediments. Sb tended to be bound to the solid phase, dominated by amorphous iron (Fe)/aluminum (Al) oxides and calcium in sediments. This study highlights that, based on current Sb migration patterns, the accumulation of sediments carried by tributaries near Sb mines in the midstream ZR and the Sb pollution caused by sediment release will be long-term, and the related environmental consequences need to be further predicted.

Aluminum adsorption and antimonite oxidation dominantly regulate antimony solubility in soils

Soil antimony (Sb) contamination occurs globally due to natural processes and human activities. Total Sb concentration in soils fails to assess its ecological risk, while determined by the concentration of available Sb, which is readily for biological uptake. Available Sb in different soils varied significantly according to soil properties. However, so far it is unknown how soil properties regulate Sb availability, and no model has been established to predict it through soil properties. In this study, 19 soils spiked with antimonite [Sb(III)] were used to identify the major factors controlling Sb availability and establish its predicting models. The results showed that available Sb in different soils varied largely depending on the contents of free aluminum (fAl), free iron (fFe) and electric conductivity (EC), which explained 33%, 27% and 24.9% of the total variation, respectively. During the first 42 days of soil aging, fAl and EC effectively predicted the concentrations of available Sb with R2 = 0.64, while during the later stages (70–150 d) of soil aging, fAl content was the unique parameter employed into the predicting model (R2 = 0.53). These results firstly demonstrate that the content of free aluminum (fAl) is the most important factor regulating Sb availability in soils, although the content of fAl is much lower than that of fFe. This finding can help to develop new remediation materials for Sb-contaminated soils. The prediction models can provide promising tools of assessing the ecological risk. In addition, Sb availability was also affected by the oxidation of Sb(III). After 150 days aging, 1–61% of Sb(III) was oxidized to pentavalent Sb [Sb(V)], which was significantly positively correlated with available Sb, suggesting that Sb(III) oxidization mobilizes Sb in soils. All these findings would help to understand Sb migration and transformation in soils, and to develop new strategies for remediating Sb-contaminated soils.

Simple and Fast Two-Step Fully Automated Methodology for the Online Speciation of Inorganic Antimony Coupled to ICP-MS

A very simple, fast and non-chromatographic methodology for inorganic antimony speciation based on Multisyringe Flow Injection Analysis (MSFIA) employing online hydride generation (HG) ICP-MS was developed. The fully automated analysis is performed in two steps: firstly, Sb(III) is quantified by ICP-MS after chemical vapor generation; then, total antimony is determined in the presence of potassium iodide as a pre-reducer of Sb(V) to Sb(III). The Sb(V) concentration is quantified by the difference between the total antimony and Sb(III) concentrations, reaching an analysis frequency of 30 h−1. The optimization was performed using a Box Behnken design. The MSFIA-HG-ICP-MS system allows the antimony speciation analysis with a detection limit of 0.016 µg L−1 for Sb(III), working in a linear range of 0.053 to 5.0 µg L−1. This method was applied for the determination of Sb(III) and Sb(V) in water samples from Maiorca Island, Spain, and the concentrations found varied from 0.10 to 0.14 µg L−1 for Sb(III) and from 0.12 to 0.28 µg L−1 for Sb(V). The results were validated by addition/recovery tests, obtaining recoveries between 90 and 111% in both cases. Furthermore, a good precision was achieved, 1.4% RSD, and sample and reagent consumption were reduced to a few mL, with the consequent decrease in waste generation. Thus, the proposed method is a good tool for the speciation of inorganic antimony at ultra-trace levels in waters, allowing its risk assessment.

Tin and Antimony as Soil Pollutants along Railway Lines—A Case Study from North-Western Croatia

The aim of this study was to determine the extent and patterns of antimony and tin contamination in soils along railway lines, as there are very few data in the literature on this subject. The study was conducted in north-western Croatia. Total and bioavailable concentrations of Sn and Sb were detected using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The following results were obtained: total concentrations of Sb ranged from 0.98 to 52.0 mg/kg and of Sn from 3.04 mg/kg to 97.6 mg/kg. The soil samples showed pronounced Sb and Sn enrichment, up to 87 and 33 times the median value for European soils, respectively. In contrast to the total concentrations, the bioavailable concentrations showed relatively low values. For Sn, the percentage of total content ranged from 0.001 to 0.021%, while for Sb it ranged from 0.001 to 0.136%. Statistical data analysis suggests that the distribution of Sb and Sn in soils near railway lines is influenced by the functional use of the site, distance from the tracks, topography, age of the railway line, and also by soil properties such as soil texture, humus content, and soil pH. This study demonstrates that rail transport is a source of soil pollution with Sn and Sb. The origin of Sb and Sn enrichment is abrasion by brakes, rails, wheels, freight losses, exhaust gasses, etc. Both elements in soils along railway lines pose an environmental risk to humans, agricultural production, and wildlife, and therefore further detailed studies are required.

Influence of Seed Source and Soil Contamination on Ecophysiological Responses of Lavandula pedunculata in Rehabilitation of Mining Areas.

Mining activities have turned many areas of the Iberian Pyrite Belt (IPB) into extreme environments with high concentrations of metal(loid)s. These harsh conditions can inhibit or reduce the colonization and/or development of most vegetation. However, some species or populations have developed ecophysiological responses to tolerate stress factors and contaminated soils. The main objectives of this study are: (i) to assess the differences in germination, growth, development and physiological behaviour against oxidative stress caused by metal(loid)s in Lavandula pedunculata (Mill.) Cav. from two different origins (a contaminated area in São Domingos mine, SE of Portugal and an uncontaminated area from Serra do Caldeirão, S of Portugal) under controlled conditions; and (ii) to assess whether it is possible to use this species for the rehabilitation of mine areas of the IPB. After germination, seedlings from São Domingos (LC) and Caldeirão (L) were planted in pots with a contaminated soil developed on gossan (CS) and in pots with an uncontaminated soil (US) under controlled conditions. Multielemental concentrations were determined in soils (total and available fractions) and plants (shoots and roots). Germination rate, shoot height, dry biomass and leaf area were determined, and pigments, glutathione, ascorbate and H2O2 contents were measured in plant shoots. Total concentrations of As, Cr, Cu, Pb and Sb in CS, and As in US exceed the intervention and maximum limits for ecosystem protection and human health. The main results showed that L. pedunculata, regardless of the seed origin, activated defence mechanisms against oxidative stress caused by high concentrations of metal(loid)s. Plants grown from seeds of both origins increased the production of AsA to preserve its reduction levels and kept the contents of GSH stable to maintain the cell’s redox state. Plants grown from seeds collected in non-contaminated areas showed a high capacity for adaptation to extreme conditions. This species showed a greater growth capacity when seeds from a contaminated area were sown in uncontaminated soils. Thus, L. pedunculata, mainly grown from seeds from contaminated areas, may be used in phytostabilization programmes in areas with soils with high contents of metal(loid)s.

Environmental Pollution Indices and Multivariate Modeling Approaches for Assessing the Potentially Harmful Elements in Bottom Sediments of Qaroun Lake, Egypt

This research intends to offer a scientific foundation for environmental monitoring and early warning which will aid in the environmental protection management of Qaroun Lake. Qaroun Lake is increasingly influenced by untreated wastewater discharge from many anthropogenic activities, making it vulnerable to pollution. For that, six environmental pollution indices, namely contamination factor (Cf), enrichment factor (EF), geo-accumulation index (Igeo), degree of contamination (Dc), pollution load index (PLI), and potential ecological risk index (RI), were utilized to assess the bottom sediment and to determine the different geo-environmental variables affecting the lake system. Cluster analysis (CA), and principal component analysis (PCA) were used to explore the potential pollution sources of heavy metal. Moreover, the efficiency of partial least-square regression (PLSR) and multiple linear regression (MLR) were tested to assess the Dc, PLI, and RI depending on the selected elements. The sediment samples were carefully collected from 16 locations of Qaroun Lake in two investigated years in 2018 and 2019. Total concentrations of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Ga, Hf, Li, Mg, Mn, Mo, Ni, P, Pb, Sb, Se, Zn, and Zr were quantified using inductively coupled plasma mass spectra (ICP-MS). According to the Cf, EF, and Igeo results, As, Cd, Ga, Hf, P, Sb, Se, and Zr demonstrated significant enrichment in sediment and were derived from anthropogenic sources. According to Dc results, all collected samples were categorized under a very high degree of contamination. Further, the results of RI showed that the lake is at very high ecological risk. Meanwhile, the PLI data indicated 59% of lake was polluted and 41% had PLI &lt; 1. The PLSR and MLR models based on studied elements presented the highest efficiency as alternative approaches to assess the Dc, PLI, and RI of sediments. For examples, the validation (Val.) models presented the best performance of these indices, with R2val = 0.948–0.989 and with model accuracy ACCv = 0.984–0.999 for PLSR, and with R2val = 0.760–0.979 and with ACCv = 0.867–0.984 for MLR. Both models for Dc, PLI, and RI showed that there was no clear overfitting or underfitting between measuring, calibrating, and validating datasets. Finally, the combinations of Cf, EF, Igeo, PLI, Dc, RI, CA, PCA, PLSR, and MLR approaches represent valuable and applicable methods for assessing the risk of potentially harmful elemental contamination in the sediment of Qaroun Lake.

Geochemical Baseline and Contamination Level Assessment of Antimony (Sb) in Sediment around Agbaou Gold Mine, Côte d’Ivoire

Agbaou is one of the most recent gold mine exploitation sites in Côte d’Ivoire. Little studies are discussed on the geochemical baseline concentration of trace metals in the wetland sediments around Agbaou gold mine. The main objectives of this study were to establish geochemical baseline values and to assess the pollution status of antimony (Sb). The geochemical baseline concentration of Sb (GBCSb) was estimated using linear regression method. In this study, total Sb concentration was analysed in sediment (10 sediment samples) collected around Agbaou gold mine site. The average Sb concentration was 5.63 ± 2.50 µg.g-1 ranging from 2.50 to 11.3 µg.g-1. The spatial distribution of Sb showed a tendency to accumulate near gold mine site. Moreover, the GBCSb (5.72 µg.g-1) was slightly higher than the average concentration found in sediments. GBC of Sb was used to calculate the anthropogenic contribution rate (R) which exhibited a positive value (R &gt; 0) for all samples, indicating that the sediments were influenced by gold mining activities. Due to lack of local baseline value in the study area, the GBCSb obtained could be used as reference value for Sb contamination level assessment in the sediments.

Precise analysis of antimony isotopic composition in geochemical materials by MC-ICP-MS

Antimony (Sb) isotopes have been shown to be promising tracers for studying Sb cycling in the environment and its impact on ecosystem and human health. Yet precise measurements of Sb isotopic composition have been challenged by low Sb concentrations and high matrix effect and by the lack of a common reference material (zero-delta). Here we report an improved analytical scheme that is capable of high-precision measurement of Sb isotopes in environmental and geochemical samples. The method employs a two-column ion exchange set-up to remove interfering matrix elements to allow Sb isotopic measurements with low Sb (< 0.15 μg/g) and high matrix content. The instrument mass bias is corrected by combining the sample-standard bracketing method with internal normalization of cadmium. To allow for interlaboratory comparisons, a standard reference material certified for the total Sb concentration, NIST SRM 3102a, is recommended as the reference standard (“zero-delta”) for Sb isotope measurements. The improved method is applied for high-precision and high-accuracy Sb isotope composition measurements in environmental and geochemical reference samples with a minimum Sb required per analysis as low as 3.0 ng. By expressing our data and previously reported literature data against the same reference standard (NIST SRM 3102a), we provide an update on isotopic compositions of various types of environmental, geological and anthropogenic materials. The improved analytical method and database aid further studies on the mechanisms of Sb isotope fractionation and its application as a tracer for the study of the sources, processes and fate of Sb in the environment.

SPX Flow Inc, USA

Antimony (Sb) isotopes have been shown to be promising tracers for studying Sb cycling in the environment and its impact on ecosystem and human health. Yet precise measurements of Sb isotopic composition have been challenged by low Sb concentrations and high matrix effect and by the lack of a common reference material (zero-delta). Here we report an improved analytical scheme that is capable of high-precision measurement of Sb isotopes in environmental and geochemical samples. The method employs a two-column ion exchange set-up to remove interfering matrix elements to allow Sb isotopic measurements with low Sb (< 0.15 μg/g) and high matrix content. The instrument mass bias is corrected by combining the sample-standard bracketing method with internal normalization of cadmium. To allow for interlaboratory comparisons, a standard reference material certified for the total Sb concentration, NIST SRM 3102a, is recommended as the reference standard (“zero-delta”) for Sb isotope measurements. The improved method is applied for high-precision and high-accuracy Sb isotope composition measurements in environmental and geochemical reference samples with a minimum Sb required per analysis as low as 3.0 ng. By expressing our data and previously reported literature data against the same reference standard (NIST SRM 3102a), we provide an update on isotopic compositions of various types of environmental, geological and anthropogenic materials. The improved analytical method and database aid further studies on the mechanisms of Sb isotope fractionation and its application as a tracer for the study of the sources, processes and fate of Sb in the environment.

Dissolved versus particulate forms of trace elements in the Athabasca River, upstream and downstream of bitumen mines and upgraders

Employing trace metal-free analytical protocols developed for polar snow and ice, water samples were collected upstream, midstream and downstream of open pit bitumen mines and upgraders along the Lower Athabasca River (AR, ~125 km). The purpose of this study was to determine whether dissolved (< 0.45 µm) and total (i.e. acid-extractable) trace element (TE) concentrations in the AR have been significantly impacted by industrial operations. Of the TEs known to be enriched in bitumen such as V, Ni, Mo and Re, only total Re was significantly more abundant downstream of industry. Total concentrations of Ag, Bi, Cd, Co, Cu, Sb, Tl and Zn were not significantly more abundant downstream of industry, compared to upstream. Moreover, these elements occur predominantly (63–96%) in the particulate fraction. In contrast to the cationic TEs, elements which occur predominantly as anions in aqueous solution (Mo, Re and Sb) are mainly in the dissolved fraction (89%, 56%, and 73%, respectively). Vanadium, Ni and Pb in the suspended solids revealed similar concentrations downstream and upstream of industry, with concentrations proportional to those of conservative, lithophile elements (Al, La, and Th), but well below their corresponding abundance in crustal rocks. Taken together, these findings suggest that physical weathering and erosion are the primary sources of metals in the AR, both upstream as well as downstream of industry, with silicates the dominant source of most of the TEs of concern.

Optimisation of laboratory antimony measurement techniques for environmental samples

ABSTRACT Antimony (Sb) is a redox-sensitive toxic trace metalloid that occurs just below arsenic (As) in Group 15 of the periodic table. These two elements share many geochemical and toxicological similarities. Antimony contamination is a global problem of emerging concern, particularly around mining and smelting areas where the element is actively mined and processed for a variety of industrial applications. The measurement and monitoring of Sb in drinking water and freshwater aquatic ecosystems are therefore becoming an increasing concern. Antimony measurement, however, is often analytically challenging owing to differing solubility of the element when it is present in various environmental redox states. The element is also very susceptible to precipitation from solution due to commonly occurring matrix effects, such as the presence of co-occurring sulphide or pH variations during sample preparation. Here we evaluated three of the most commonly used methods of analysis for measurement of total Sb concentration in aqueous samples and in freshwater sediments; ICP-MS, ICP-OES and UV-Vis spectrophotometry. Methods were evaluated on the basis of analytical precision/reproducibility, cost and potential environmental hazard. Analytical results are presented both for standards and environmental test samples. Statistical analysis of results indicates that analytical reliability of these methods, ranked in order of decreasing reliability, follows the order ICP-MS, ICP-OES and UV-Vis spectrophotometric method. Rankings based on increasing order of cost and environmental hazard of reagents both follow an opposing trend of UV-Vis spectrophotometric method, ICP-OES and ICP-MS.

Determination of total and bioavailable As and Sb in children's paints using the MSFIA system coupled to HG-AFS.

In this study, the use of hydride generation atomic fluorescence spectrometry (HG-AFS) coupled with the multi-syringe flow injection analysis (MSFIA) has been proposed in the application of the Doehlert design to optimise the determination of As and Sb in gouache and tempera children's paints. The determination of the total and bioavailable As and Sb in paint samples from various brands and colours was also investigated. The limits of quantification (LOQ) obtained for the determination of As and Sb were 14.0 and 8.6 ng g-1, respectively. The accuracy and precision of the method were evaluated through recovery tests (by the analyte addition method) at three levels for both elements, and by the analysis of certified reference materials of clay (CRM 052, Loamy Clay 1) and river water (SLRS-4). Twenty paint samples, manufactured in China, Italy, Spain and Brazil, were analysed. The concentrations of As varied between below LOQ (<14 ng g-1) and 136.0 ± 1.1 ng g-1 (average value of 101.0 ng g-1, n = 10), and Sb between below LOQ (<8.6 ng g-1) and 74.0 ± 5.4 ng g-1 (average value of 21.7 ng g-1, n = 17). The children's paint samples presented As and Sb concentrations that were below the maximum values established by the National Institute of Metrology, Quality and Technology (INMETRO), as well as by the European legislation Directive 2009/48/EC. Based on the obtained results for the total As and Sb concentrations, eight samples were selected to evaluate the migration or bioavailability of As and Sb after solubilisation in HCl solution. The obtained results showed that for the eight analysed samples, the concentration of both elements after solubilisation in HCl solution were below the LOQ (<16.2 ng g-1 for As and <7.1 ng g-1 for Sb). These values correspond to the limits of analytical concentrations of As and Sb established by INMETRO and the Brazilian Association of Technical Standards (ABNT). The determined concentrations of As and Sb guarantee the safety (with regards to these elements) for children when using the analysed paint samples since they do not cause any health risk. The analytical method for the determination of the total and bioavailable As and Sb in children's paints was efficient, accurate and precise.

Speciation of Antimony in Injectable Leishmanicidal Drugs by Lowering Citric Acid Concentration Used in Hydride Generation Atomic Absorption Spectrometry Analysis

This study proposes a procedure for speciation of antimony by hydride generation atomic absorption spectrometry in pentavalent antimony drugs. The SbIII content was determined by selective generation of SbH3 in medium with higher SbV concentration using 4 to 20-fold lower citric acid solutions than recommended in the available literature. The multivariate optimization of the methods was performed through factorial design followed by a central composite design (CCD). The limit of detection (LOD) and limit of quantification (LOQ) were calculated at 0.15 and 0.05 µg L-1 and 0.48 and 0.17 µg L-1, for total Sb and SbIII, respectively. The relative standard deviation (RSD) values ranged from 3.1 to 19.6% and 9.1 to 20.1%, while recovery ranged from 95.6 to 102.3% and 89.1 to 108.1%, for total Sb and SbIII, respectively. This method was applied for the analysis of meglumine antimoniate samples. Total Sb and SbIII concentrations ranged from 79.2 to 101.1 mg mL-1 and 0.08 to 0.41 mg mL-1, respectively.

Speciation analysis of inorganic As and Sb in urban dust using slurry sampling and detection by fast sequential hydride generation atomic absorption spectrometry.

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 (1.0molL-1 HCl and 0.9%mv-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 1.03mgkg-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 38μm. 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.