Antimony Species Research Articles

Species-specific Antimony Isotope Analysis by High Performance Liquid Chromatography Coupled with Multicollector ICPMS Using Hydride Generation as an Interface.

A novel method has been developed for the simultaneous online determination of the isotopic compositions of different antimony (Sb) species in a single analytical run using high-performance liquid chromatography (HPLC) coupled with multicollector inductively coupled plasma mass spectrometry (MC-ICPMS), with hydride generation (HG) serving as the interface. Various parameters affecting the precision of Sb isotope analysis including HG conditions, transient signal processing methods and peak integration windows, were optimized. The linear regression slope method and a 100% peak integration window provided the optimal precision. Under optimized conditions, our method achieved external 2SD precisions better than 0.05‰ for both Sb(III) and Sb(V), with minimal consumption of 0.5 ng for Sb(III) and 5 ng for Sb(V). Furthermore, flow injection (FI) coupled with HG-MC-ICPMS demonstrated precise Sb isotopic analysis with sample requirements as low as 0.25 ng. The proposed methods were validated by analyzing δ123Sb in synthetic solutions and reference materials. Additionally, it was applied to investigate isotopic fractionation during the reduction of Sb(V) by KI, revealing preferential reduction of the light Sb isotope(121Sb). The isotopic compositions of Sb(V) varied from -0.04- 1.18‰, fitting well with a Rayleigh fractionation model and yielding a fractionation factor (αSb(III)-Sb(V)) of 0.99831. In summary, this approach enables high precision isotopic analysis of Sb(III) and Sb(V) simultaneously with reduced sample consumption, providing a powerful tool for investigating Sb isotopic fractionation in various environmental processes and advancing our understanding of the Sb biogeochemical cycle.

Compositional Differences of Various Sorption States of Cu and Cd on Goethite in the Presence of Oxyanions: A Quantitative Study.

The anionic species of antimony(V) and phosphate(V) are commonly found in the contaminated soil of mining areas, exerting a significant influence on the sorption of heavy metals and thus affecting their migration. This study quantitatively discussed the sorption mechanism of Sb and P in promoting the sorption of Cd or Cu on goethite through a series of extraction methods. In the single sorption system, the majority of Cu (87-98%) is adsorbed on goethite in the form of EDTA-extractable Cu (EF Cu, possibly inner-sphere complexes) under pH conditions of 3.5-6.5. Cadmium is primarily adsorbed in the form of EDTA-extractable Cd (49-71%), with a considerable amount of Mg(NO3)2 extractable Cd (MF Cd, possibly outer-sphere complexes) also present (25-51%), within the pH range of 4.5-7.5. The presence of either Sb or P greatly enhances the sorption of Cd and Cu on goethite, although the mechanisms differ significantly. Sb enhances the sorption of Cu mainly by increasing the amount of EF Cu (61.7-68.1% of total Cu enhancement), with less significant effects on MF Cu. Furthermore, Sb shows similar enhancing effects on both MF Cd and EF Cd. As the pH increases, the enhancing effects of Sb on various forms of Cu and Cd decrease. Phosphate mainly promotes the formation of MF Cu and MF Cd, accounting for 53.9- 80.8% (Cu) and 78.0-94.9% (Cd) of total enhancement at different pH levels. ΔMF and ΔEF Cu increase with increasing pH when P is present, while ΔMF/ΔEF Cd remains essentially constant. Based on the extracted results and characterization analysis, the main mechanism of synergistic sorption between elements was discussed, and the connection modes of elements at the goethite interface were preliminarily speculated. The results indicate that the promotion of oxyanions on the fixation of heavy metal cations is more complex than expected, making it difficult to describe using only one mechanism.

Evaluating the influence of alternating flooding and drainage on antimony speciation and translocation in a soil-rice system

The quantitative evaluation of antimony (Sb) accumulation in rice has garnered significant attention due to the potential risks to human health. A pot experiment was conducted to investigate the essential nodes of Sb transfer in soil-rice system. Seven step extract results showed that during the flooding period, organic matter releasing was the primary factor contributing 14.1 % to the increase in Sb availability, while weakly crystallized Fe-Mn oxides and sulfides respectively accounted for 6.9 % and 1.42 %. During the drainage period, a notable increase in active Sb was observed, coinciding with decrease in Fe-Mn oxides and sulfides bond Sb. The migration rate constant of Sb from the root to the above-ground parts increased dramatically during the early flooding stage, being 2000 times higher than that in the mid-to-late stage. The shoot-to-grain migration rate constant remained low, at 1.07 × 10−2 d−1 and 3.52 × 10−3 d−1 during the flooding and drainage periods, respectively. Consequently, Sb accumulation amount in the grain (11.5 μg) was 2.2 times and 6.24 times lower than that in the roots and shoots, respectively. This study quantitatively evaluates the key processes controlling Sb transformation, uptake and translocation throughout different growth stages of the rice plant.

Antimony Vaporization and Condensation in Simulated Flash Smelting Off-Gas Train Conditions

Antimony is one of the most deleterious impurity elements in copper smelting and has a strong tendency to vaporize in the smelting furnace resulting in an enrichment of antimony in smelter flue dusts. The vaporization and condensation behavior of antimony species was studied in dust-free conditions simulating the off-gas train of a Flash Smelting Furnace at temperatures below 1273 K (1000 °C). The influences of the oxygen partial pressure and the condensate formation temperature on the characteristics of the precipitated antimony species were determined. It was found that practically all the vaporized antimony species precipitated between 853 K and 546 K (580 °C and 273 °C) and that a higher oxygen partial pressure favored precipitation at higher temperatures. The formation of antimony sulfate, which thermodynamically is the most stable antimony species in the studied conditions at temperatures below approximately 723 K (450 °C), was found to be kinetically constrained and the vaporized antimony species precipitated as oxides or sulfides depending on the oxygen partial pressure and the precipitate formation temperature.

Biochar-Sulfate Reducing Bacteria synergy: A green approach for antimony removal and recovery from high-concentrated waters

Environments with elevated antimony (Sb) levels often result from industrial and mining activities, causing harm to ecosystems due to the inherent toxicity. Traditional treatments aim to eliminate or decrease Sb toxicity, yet they often result in the generation of secondary pollution. This study explores a novel approach for enhancing biological sulfate-reduction by biochar addition to cope with high Sb concentrations. Moreover, this research postulates sulfate-reduction bioprocess as a feasible alternative to obtain valuable antimony sulfide. The findings indicate that sulfate reduction effectively removes antimony, particularly at high concentrations, using a non-specialized inoculum. Biochar plays a pivotal role in enhancing sulfate-reduction rates, reducing lag-phase periods, and enriching the microorganisms responsible for sulfate reduction.Interestingly, lower concentrations of Sb(III) (5–40 mg/L) and Sb(V) (5–100 mg/L) exhibited a lower removal percentage compared to higher concentrations of Sb(III) (80–500 mg/L) and Sb(V) (200–1000 mg/L). This phenomenon was attributed to the excess sulfide hindering the equilibrium of the first-order reaction at lower concentrations, while at higher concentrations, the reaction proceeded more rapidly. A combination of biochemical and physicochemical reactions facilitated the removal of >95 % Sb(III) and >97 % Sb(V) using biochar.Furthermore, various taxa displayed a significant logarithmic rate of change in their abundance, influenced by the application of biochar or the introduction of distinct antimony species. The biogenic sulfide generated through the sulfate reduction process reacted with the Sb species, resulting in the precipitation of stibnite (Sb2S3), Na3SbS3, and Na3SbS4. These precipitates are considered crucial precursors in electronic applications.In conclusion, this study constitutes a pioneering exploration of elevated antimony (Sb) concentrations under sulfate-reducing conditions, significantly contributing to an advancement of knowledge in the application of biological processes.

Cellulose nanocrystal-infused polymer hydrogel imbued with ferric-manganese oxide nanoparticles for efficient antinomy removal

Antimony is a highly poisonous pollutant that needs to be removed from water to ensured safety. In this work, we have fabricated a novel adsorbent, the ferric-manganese oxide (FeMnOx) nanoparticles embedded cellulose nanocrystal-based polymer hydrogel (FeMnOx @CNC-g-PAA/qP4VP, denoted as FMO@CPqP), specifically engineered for the remediation of antimony-laden water. Comprehensive evaluations have been conducted to investigate the efficacy of the FMO@CPqP hydrogel in removal of antimony from water. The hydrogel exhibits superior affinity for antimony, with maximum adsorption capacities of 276.1 mg/g for Sb(III) and 286.8 mg/g for Sb(V). The adsorptive dynamics, governed by the kinetics and isotherm analyses, elucidate that the immobilization of both Sb(III) and Sb(V) is facilitated through a homogeneous and monolayer chemisorption mechanism. The hydrogel has a three-dimensional interconnected porous structure and exhibits good swelling behavior, which facilitates the rapid absorption of antimony ions by this high surface area hydrogel into the channels. Furthermore, various effects, including the oxidation and inner-sphere coordination mediated by FeMnOx NPs and the electrostatic attractions of the quaternized P4VP chains, promote the immobilization of antimony species. Owing to its high removal efficiency, stability and reusability, the FMO@CPqP hydrogel emerges as an exemplary candidate for the removal of antimony contaminants in water treatment processes.

Optimizing Antimony Speciation Analysis via Frontal Chromatography-ICP-MS to Explore the Release of PET Additives.

Antimony (Sb) contamination poses significant environmental and health concerns due to its toxic nature and widespread presence, largely from anthropogenic activities. This study addresses the urgent need for an accurate speciation analysis of Sb, particularly in water sources, emphasizing its migration from polyethylene terephthalate (PET) plastic materials. Current methodologies primarily focus on total Sb content, leaving a critical knowledge gap for its speciation. Here, we present a novel analytical approach utilizing frontal chromatography coupled with inductively coupled plasma mass spectrometry (FC-ICP-MS) for the rapid speciation analysis of Sb(III) and Sb(V) in water. Systematic optimization of the FC-ICP-MS method was achieved through multivariate data analysis, resulting in a remarkably short analysis time of 150 s with a limit of detection below 1 ng kg-1. The optimized method was then applied to characterize PET leaching, revealing a marked effect of the plastic aging and manufacturing process not only on the total amount of Sb released but also on the nature of leached Sb species. This evidence demonstrates the effectiveness of the FC-ICP-MS approach in addressing such an environmental concern, benchmarking a new standard for Sb speciation analysis in consideration of its simplicity, cost effectiveness, greenness, and broad applicability in environmental and health monitoring.

Coin cell constructed symmetric supercapacitor based on binder-free antimony trioxide (Sb2O3) in heteroatom doped carbon nanofibers

Antimony trioxide nanoparticles are synthesized in binder-free, self-standing, and nitrogen and sulfur as heteroatoms doped carbon nanofibers (Sb2O3-NSCFs). Two-step method including electrospinning and heat treatment is utilized to convert antimony species to nano-sized antimony nanoparticles. Structural, morphological, chemical composition, and surface area/pore size analysis of the materials are investigated using a series of analysis. The electrochemical performance of the materials is evaluated using both three- and two-electrode systems in basic electrolyte. The Sb2O3-NSCFs electrode shows a specific capacitance of 354.4 F/g at 1 A/g and the charge storage mechanism is investigated. The constructed coin-cell symmetric supercapacitor (Sb2O3-NSCF//Sb2O3-NSCF) exhibits a specific energy of 9.2 Wh/kg at 300 W/kg and also retains its capacitance of 94.4 % over 10 000 cycles.

Tissue-specific deposition, speciation and transport of antimony in rice.

Rice (Oryza sativa) as a staple food is a potential intake source of antimony (Sb), a toxic metalloid. However, how rice accumulates this element is still poorly understood. Here, we investigated tissue-specific deposition, speciation, and transport of Sb in rice. We found that Sb(III) is the preferential form of Sb uptake in rice, but most Sb accumulates in the roots, resulting in a very low root-to-shoot translocation (less than 2%). Analysis of Sb deposition with laser ablation-inductively coupled plasma-mass spectrometry showed that most Sb deposits at the root exodermis. Furthermore, we found that Sb is mainly present as Sb(III) in the root cell sap after uptake. Further characterization showed that Sb(III) uptake is mediated by Low silicon rice 1 (Lsi1), a Si permeable transporter. Lsi1 showed transport activity for Sb(III) rather than Sb(V) in yeast (Saccharomyces cerevisiae). Knockout of Lsi1 resulted in a significant decrease in Sb accumulation in both roots and shoots. Sb concentration in the root cell sap of two independent lsi1 mutants decreased to less than 3% of that in wild-type rice, indicating that Lsi1 is a major transporter for Sb(III) uptake. Knockout of Lsi1 also enhanced rice tolerance to Sb toxicity. However, knockout of Si efflux transporter genes, including Lsi2 and Lsi3, did not affect Sb accumulation. Taken together, our results showed that Sb(III) is taken up by Lsi1 localized at the root exodermis and is deposited at this cell layer due to lack of Sb efflux transporters in rice.

The role of an Sb-oxidizing bacterium in modulating antimony speciation and iron plaque formation to reduce the accumulation and toxicity of Sb in rice (Oryza sativa L.)

Microbial antimony (Sb) oxidation in the root rhizosphere and the formation of iron plaque (IP) on the root surface are considered as two separate strategies to mitigate Sb(III) phytotoxicity. Here, the effect of an Sb-oxidizing bacterium Bacillus sp. S3 on IP characteristics of rice exposed to Sb(III) and its alleviating effects on plant growth were investigated. The results revealed that Fe(II) supply promoted IP formation under Sb(III) stress. However, the formed IP facilitated rather than hindered the uptake of Sb by rice roots. In contrast, the combined application of Fe(II) and Bacillus sp. S3 effectively alleviated Sb(III) toxicity in rice, resulting in improved rice growth and photosynthesis, reduced oxidative stress levels, enhanced antioxidant systems, and restricted Sb uptake and translocation. Despite the ability of Bacillus sp. S3 to oxidize Fe(II), bacterial inoculation inhibited the formation of IP, resulting in a reduction in Sb absorption on IP and uptake into the roots. Additionally, the bacterial inoculum enhanced the transformation of Sb(III) to less toxic Sb(V) in the culture solution, further influencing the adsorption of Sb onto IP. These findings highlight the potential of combining microbial Sb oxidation and IP as an effective strategy for minimizing Sb toxicity in sustainable rice production systems.

A step towards understanding plastic complexity: Antimony speciation in consumer plastics and synthetic textiles revealed by XAS

We identified the antimony species present in a wide variety of plastic samples by X ray absorption spectroscopy (XAS) at the Sb L3-edge. The samples contained different concentrations of antimony (Sb), ranging from PET bottles in which Sb compounds are used as catalysts, with concentrations around 300 mg/kg, to electrical equipment in which the element is used as a flame retardant, with concentrations of several tens of thousands of mg/kg. Although the shape of the spectra at the L3-edge is quite similar for all Sb reference materials, we were able to identify antimony glycolate or acetate in PET bottles, bound organic Sb in c-PET trays and senarmontite in electrical materials as the main Sb components. In samples with high Ca content (e.g., electrical objects, some c-PET food trays and textiles) the Ca Ka emission line interferes with the Sb La line by introducing a high background which reduces the signal-to-noise ratio in the Sb XAS spectrum, resulting in noisy and distorted spectra. The element-resolved map on a PET bottle sample revealed both Sb and Ca hot spots of around 10-20 microns in size, with no correlation.

Non-chromatographic speciation analysis of antimony in water samples assisted by vinylimidazole-based polymeric sorbent

A functional polymeric material was synthesized via precipitation copolymerization of vinylimidazole and trimethylolpropane trimethacrylate and used as а sorbent for selective separation and determination of Sb(V) and Sb(III). The extraction efficiency of the newly synthesized material toward Sb(III) and Sb(V) was studied in batch mode. In weakly acidic aqueous solutions, at pH 5 – 6, Sb(V) was entirely retained on the polymeric sorbent, while Sb(III) remained in the supernatant. Quantitative elution of Sb(V) was accomplished with 1 mM diammonium hydrogen citrate for 30 min. An analytical procedure for non-chromatographic speciation and determination of inorganic antimony was developed. Concentrations of the target Sb(V) and the non-extractable Sb(III) were measured by ICP-OES with limits of quantitation of 4.2 μg/l and 3.4 μg/l, respectively. The method showed good accuracy, high precision, and applicability to low-mineralized waters, enabling up to 25-fold preconcentration of Sb(V).

Antimony speciation in soils in areas subjected to industrial anthropopressure

Antimony speciation in soils in areas subjected to industrial anthropopressure

Abiotic aerobic oxidation pathways of stibnite revealed by oxygen and sulfur isotope systematics of sulfate

The environmental threat posed by stibnite is an important geoenvironmental issue of current concern. To better understand stibnite oxidation pathways, aerobic abiotic batch experiments were conducted in aqueous solution with varying δ18OH2O value at initial neutral pH for different lengths of time (15-300 days). The sulfate oxygen and sulfur isotope compositions as well as concentrations of sulfur and antimony species were determined. The sulfur isotope fractionation factor (Δ34SSO4-stibnite) values decreased from 0.8‰ to -2.1‰ during the first 90 days, and increased to 2.6‰ at the 180 days, indicating the dominated intermediate sulfur species such as S2O32−, S0, and H2S (g) involved in Sb2S3 oxidation processes. The incorporation of O into sulfate derived from O2 (∼100%) indicated that the dissociated O2 was only directly adsorbed on the stibnite-S sites in the initial stage (0-90 days). The proportion of O incorporation into sulfate from water (27%-52%) increased in the late stage (90-300 days), which suggested the oxidation mechanism changed to hydroxyl attack on stibnite-S sites promoted by nearby adsorbed O2 on stibnite-Sb sites. The exchange of oxygen between sulfite and water may also contributed to the increase of water derived O into SO42−. The new insight of stibnite oxidation pathway contributes to the understanding of sulfide oxidation mechanism and helps to interpret field data.

Streamlining antimony speciation analysis in natural waters with frontal chromatography-ICP-MS

Antimony is a naturally occurring toxic metalloid whose cycling has been greatly affected by human activities. It is considered as a priority interest pollutant and limits have been set for its presence in e.g., drinking water. Inorganic Sb redox species include the III and V oxidation states and they exhibit different environmental behavior, bioavailability, mobility and toxicity, stimulating the development of several procedures for speciation analysis, mainly based on the hyphenation of liquid chromatography and spectrometric methods (usually ICP-MS or atomic fluorescence). Here, the development and validation of a sensitive, fast, high throughput and cost effective procedure for the selective determination of Sb(III) and Sb(V) in water samples is reported. The method is based on the separation of the two species by a short, low pressure homemade cation exchange column, thus avoiding the use of the LC instrumentation, and detection by ICP-MS for sensitive determination. A very fast analysis time of 3 min is enough to separate and detect the two species with detection limits (LOD) below 1 ng L−1 for both Sb(III) and Sb(V). The limit of linearity and possible interferences due to the presence of a large excess of one species over the other were also investigated. Validation was successfully achieved by a spike and recovery strategy on mineral water samples. The procedure was finally compared to existing ones highlighting its benefits in terms of analysis time, very low limits of detection and favorable instrumental configuration. Possible advances in terms of application to different environmental matrices were also discussed.

An Overview of the Behavior of Concentrates with Arsenic, Antimony, and Bismuth under Roasting Conditions

It is well-known that the mining industry in Chile and the world is searching for eco-friendly, highly efficient mineral treatments. This is because the content of toxic elements such as arsenic, antimony, and bismuth have increased in the copper concentrates in the last years. This trend has affected the market of this metal, as well as increased the potential of producing solid wastes that represent a threat to the environment. In this paper, a review on the fundamentals of the current treatments aimed at removing arsenic, antimony, and bismuth from copper concentrates under roasting conditions is presented. The literature survey included the research conducted from 2000 until now and is focused on the different types of roasting of copper concentrates reported in the literature. A summary of the experimental conditions and major findings of each work is discussed. Depending on the type of roasting, the behavior of arsenic, antimony, and bismuth species during the experiments is analyzed.

Speciation and determination of inorganic antimony in tea infusion by using solid-phase extraction-based liquid chromatography-inductively coupled plasma-mass spectrometry

In this work, we developed a method to separate and detect inorganic antimony (iSb) in tea infusions based on liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). Considering that iSb was present in tea infusions in trace amounts, a commercial solid-phase extraction (SPE) column was employed to enrich iSb(III) and iSb(V). In this study, we found that iSb exists in tea infusions in a bound state with an unknown substance rather than in a free state. Therefore, the enrichment step was combined with oxidation and reduction processes. Because of the enrichment process and the high sensitivity of LC-ICP-MS, the LODs of iSb(III) and iSb(V) were both as low as 0.03 μg L−1. The RSDs (n = 6) of iSb(III) and iSb(V) were all below 8.1%, and the recoveries (n = 6) were 92–96% and 90–94%, respectively. Then, a total of six tea infusion samples were inspected. The data revealed that the total Sb in the tea infusions ranged from 0.22 to 0.97 μg L−1, and we found that 50–83% of the total Sb in the tea infusion was iSb. This method is worth promoting since it has satisfying methodological performance.

Influence of Antimony Species on Electrical Properties of Sb-Doped Zinc Oxide Thin Films Prepared by Pulsed Laser Deposition.

This study systematically investigates the influence of antimony (Sb) species on the electrical properties of Sb-doped zinc oxide (SZO) thin films prepared by pulsed laser deposition in an oxygen-rich environment. The Sb species-related defects were controlled through a qualitative change in energy per atom by increasing the Sb content in the Sb2O3:ZnO-ablating target. By increasing the content of Sb2O3 (wt.%) in the target, Sb3+ became the dominant Sb ablation species in the plasma plume. Consequently, n-type conductivity was converted to p-type conductivity in the SZO thin films prepared using the ablating target containing 2 wt.% Sb2O3. The substituted Sb species in the Zn site (SbZn3+ and SbZn+) were responsible for forming n-type conductivity at low-level Sb doping. On the other hand, the Sb-Zn complex defects (SbZn-2VZn) contributed to the formation of p-type conductivity at high-level doping. The increase in Sb2O3 content in the ablating target, leading to a qualitative change in energy per Sb ion, offers a new pathway to achieve high-performing optoelectronics using ZnO-based p-n junctions.

Distribution, metabolism, and toxicity of antimony species in wistar rats. A bio-analytical approach

This work studied the distribution, reactivity, and biological effects of pentavalent or trivalent antimony (Sb(V), Sb(III)) and N-methylglucamine antimonate (NMG-Sb(V)) in Wistar Rats. The expression of fibrosis genes such as α − SMA, PAI-1, and CTGF were determined in Liver, and Kidney tissues. Wistar rats were treated with different concentrations of Sb(V), Sb(III), As(V) and As(III), and MA via intra-peritoneal injections. The results indicated a noteworthy elevation in mRNA levels of plasminogen activator 1 (PAI-1) in the kidneys of rats that were injected. The main accumulation site for Sb(V) was observed to be the liver, from which it is primarily excreted in its reduced form (Sb(III)) through the urine. The generation of Sb(III) in the kidneys has been found to induce damage through the expression of α-SMA and CTGF, and also lead to a higher creatinine clearance compared to As(III).

Kinetics of coupled sorption and abiotic oxidation of antimony(III) in soils

A quantitative evaluation of the dynamics of antimony (Sb) species transformation when Sb(III) enters the soil matrix would facilitate the understanding of the speciation and environmental fate of Sb in natural environments. Towards this end, the coupled sorption and abiotic oxidation kinetics of Sb(III) were examined across 12 soils with a 24 h timeframe. The soil-solution distribution coefficients (Kd) of Sb ranged between 214 and 5965 L kg−1. Both apparent and mechanistic kinetic models were used to described the process. The apparent kinetic model indicated a two-rate oxidation and associated stabilization behavior of Sb in soils. The fast oxidation rate constants ranged from 0.147 to 0.763 h−1, which were one to two orders of magnitudes higher than the slow rate constants (0.002–0.039 h−1). Iron and Mn oxides were identified as the key soil components associated with adsorptive-oxidative sites (SOH) and oxidative sites (Mn-OH) of soils for Sb species, and these were subsequently integrated into the mechanistic kinetic model. This model included the adsorption–desorption of Sb(III) as well as the oxidation product, Sb(V) on the SOH, the oxidation of Sb(III) by SOH and Mn-OH, and the stabilization of both Sb(III) and Sb(V). The model produced a global fit for dissolved and adsorbed Sb species across the 12 soils. This study provides new information for predicting the dynamics of Sb in soils when multiple adsorption–desorption, oxidation and stabilization reactions are coupled in natural environments.