Speciation Analysis Of Antimony Research Articles

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.

Antimony speciation on a dithiothreitol-functionalized two-dimensional Au@Ag array by surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS), a fast and non-destructive detection technique, can be potentially used for the on-site analysis of antimony species. However, SERS quantification of antimony species has been rarely performed. This study fabricated a two-dimensional (2D) Au@Ag–dithiothreitol (DTT) array for antimony speciation analysis. This array was able to detect antimony at concentrations as low as Sb(III) = 1.05 µg·L−1 and Sb(V) = 3.81 µg·L−1. Moreover, it exhibited good uniformity with a relative standard deviation of 16.2% and recoveries of 88–93%. The results of three-dimensional finite-difference time-domain simulations revealed that the 2D Au@Ag array with 25 nm-Au cores, 6 nm-Ag shells, and 2 nm-interparticle gaps created a strong localized surface plasmon resonance. The DTT functionalization of the 2D Au@Ag array facilitated selective adsorption and SERS detection of antimony ions. By combining the electromagnetic and chemical mechanisms, antimony speciation analysis was successfully performed using the 2D Au@Ag–DTT array, suggesting a new on-site method for monitoring small molecules.

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.

A review of the environmental chemical behavior, detection and treatment of antimony

Antimony (Sb), a toxic metalloid element, is located in the Group VA of the fifth period of the periodic table of elements. At present, with the wide use of antimony containing products in the world and the corresponding mining activities, a large number of antimony containing waste generated in these processes has also been released to the environment, resulting in antimony pollution has become a problem that cannot be ignored. People exposed to high concentrations of antimony will produce a series of health risks, which may lead to vomiting, diarrhea, rash and other diseases, and even cancer. Antimony in the environment comes from natural processes (ore weathering, volcanic activity) and human activities (mining and smelting, use of antimony containing products, fossil fuel combustion, etc.). Similar to many elements, the toxicity of antimony is closely related to its chemical form, and the toxicity of Sb(III) is much higher than Sb(V). Antimony exists in various chemical forms in the environment (mainly Sb(III) and Sb(V)), and its environmental chemical behavior is easily affected by various environmental factors. Redox conditions can change the chemical form of antimony and affect its migration and transformation in environmental media. Once the antimony minerals are oxidized in contact with the air, antimony will be released in a dissolved state, and then attached to the surface of various solid particles in the tailings in the form of adsorption. It is easy to migrate and diffuse to the surrounding environment under the leaching of surface water, and absorbed by plant roots. In addition, this review also emphasizes the detection methods of antimony, in which the development of combined technology is an increasingly attractive research field in antimony speciation analysis. Finally, we provide several commonly used Sb removal technologies, and critically analyze the remarkable characteristics and removal mechanism of these technologies, hoping to provide reference for the treatment and research of antimony pollution. • The research progress of antimony in recent years is summarized. • Redox conditions and speciation affect the fate of antimony in the environment. • The treatment of antimony in environment media is systematically introduced. • Bioremediation can effectively reduce antimony pollution and its toxicity.

LC-ICP-OES method for antimony speciation analysis in liquid samples

A method for the analysis of different species of antimony (Sb) that couples liquid chromatography with an inductively coupled plasma-optical emission spectrometry (LC-ICP-OES) system is presented. The method is simple and reliable to separate and quantify directly and simultaneously Sb(III) and Sb(V) in aqueous samples. The calibration curves showed high linearity at the three wavelengths tested. The limits of detection ranged from 24.9 to 32.3 μg/L for Sb(III) and from 36.2 to 46.0 μg/L for Sb(V), at the three wavelengths evaluated. The limit of detection for this method varied depending on the wavelength used. The lowest limit of quantification for Sb(V) (49.9 μg/L) and Sb(III) (80.7 μg/L) was obtained at a wavelength of 217.582 nm. The method sensitivity for Sb(V) was higher compared to Sb(III) at all the wavelengths considered. Samples containing different concentrations of Sb(III) and Sb(V) in three different matrices, i.e., water, basal culture medium, and anaerobic sludge plus basal medium, were analyzed. The coefficients of variation were low and ranged from 0.1 to 5.0 depending on the sample matrix. Recoveries of Sb(III) and Sb(V) were higher than 90% independently of the matrix analyzed and the wavelength used in the analysis.

Arsenic and antimony speciation analysis in copper electrolyte by liquid chromatography coupled to hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS)

A novel method based on HPLC-HG-AFS is proposed for the determination of As and Sb redox couples in in copper electrolyte samples, which are characterized by extreme acidity and high metallic content (Cu and Ni in the g L−1 range).

Antimony speciation analysis by hydride trapping on hybrid nanoparticles packed in a needle trap device with electro-thermal atomic absorption spectrometry determination

Novel hybrid nanoparticles show faster antimony adsorption kinetics compared to single nanoparticles, becoming superior sorbents for analytical applications.

Dispersive micro-solid phase extraction combined with dispersive liquid-liquid microextraction for speciation analysis of antimony by electrothermal vaporization inductively coupled plasma mass spectrometry

A method was developed for speciation analysis of antimony by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) after preconcentration/separation using dispersive micro-solid phase extraction (DMSPE) and dispersive liquid-liquid micro-extraction (DLLME). In DMSPE, titanium dioxide nanofibers were used for preconcentration and separation of analytes. The upper aqueous phase and elution solution from DMSPE were used for further preconcentration and separation of Sb(III) and Sb(V) by DLLME without any pre-oxidation or pre-reduction operation, respectively. The extracts from DLLME were used for ETV-ICP-MS determination with APDC as a chemical modifier. Under optimal conditions, the detection limits of this method were 0.019 and 0.025pgmL−1 with relative standard deviations of 5.7% and 6.9% for Sb(III) and Sb(V) (c=1.0ngmL−1, n=9), respectively. This method was applied for speciation analysis of Sb and its distribution in the tea leaves and the tea infusion, including total, suspended, soluble, organic and inorganic Sb as well as Sb(III) and Sb(V). The results showed that the contents of Sb are 62.7, 12.9 and 47.3ngg−1 in the tea leaves, tea residue and tea soup, respectively; those of soluble, organic, inorganic, Sb(III) and Sb(V) are 0.41, 0.11, 0.29, 0.21 and 0.07ngmL−1 in the tea soup, respectively. A certified reference material of tea leaves (GBW 07605) was analyzed by this method with satisfactory results.

On line automated system for the determination of Sb(V), Sb(III), thrimethyl antimony(v) and total antimony in soil employing multisyringe flow injection analysis coupled to HG-AFS

This paper proposes the use of a multisyringe flow injection analysis (MSFIA) system for inorganic antimony speciation analysis, trimethyl antimony(V) and determination of total antimony in soil samples using hydride generation atomic fluorescence spectrometry (HG-AFS). Total antimony has been determined after reduction of antimony(V) to antimony(III) using potassium iodide and ascorbic acid. For determination of total inorganic antimony the sample is percolated in a mini-column containing the Dowex 50W-X8 resin for retention of the organic species of antimony. Antimony(III) is quantified in presence of 8-hydroxyquinoline as masking agent for antimony(V) after an extraction step of the organic antimony species using the also same mini-column. The trimethyl antimony(V) content is found by difference between total antimony and total inorganic antimony. By other hand, antimony(V) is quantified by difference between total inorganic antimony and antimony(III). The analytical determinations were performed using sodium tetrahydroborate as reducing agent. The optimization step was performed using two-level full factorial design and Doehlert matrix involving the factors: hydrochloric acid and sodium tetrahydroborate concentrations and sample flow rate. The optimized experimental conditions allow the antimony determination utilizing the external calibration technique with limits of detection and quantification of 0.9 and 3.1ngg−1, respectively, and a precision expressed as relative standard deviation of 3.2% for an antimony solution of 5.0µgL−1. The method accuracy was confirmed by analysis of the soil certified reference material furnished from Sigma-Aldrich RTC. Additionally, addition/recovery tests were performed employing synthetic solutions prepared using trimethyl antimony(V), antimony(III), antimony(V) and five soil samples. The antimony extraction step was performed in a closed system using hydrochloric acid, ultrasonic radiation and controlled temperature. The method proposed was applied for analysis of thirteen soil samples collected in different sites of the Balearic Islands, Spain, and the results obtained varied from 19 to 46ngg−1 for trimethyl antimony(V) and from 113 to 215ngg−1 for total inorganic antimony. The concentrations obtained to antimony(V) were always higher than for antimony(III) in all the analyzed samples.

Speciation of inorganic antimony (III & V) employing polyurethane foam loaded with bromopyrogallol red

In this work, the speciation analysis of inorganic antimony (Sb(III) and Sb(V)) is proposed using polyurethane foam loaded with bromopyrogallol red (PUF-BPR) as a selective sorbent for Sb(III). The quantification of Sb in the solutions was performed by graphite furnace atomic absorption spectrometry (GF AAS), and several variables that could affect the performance of the method were carefully evaluated. The best conditions for the sorption of Sb(III) were achieved by shaking 50mg of PUF-BPR with the solutions containing Sb(III) at pH 4.0 for 90min. In this condition, the retention of Sb(V) was not significant, whereas the removal of Sb(III) from the solution was higher than 95%. The desorption of Sb(III) from loaded PUF-BPR was possible by shaking the loaded foam with 7.5mL of a 2.5molL−1 HNO3 solution for 30min. No interference of metal cations was observed on the solid-phase extraction of Sb(III) by PUF-BPR. The developed method was applied in the speciation analysis of antimony in river water samples fortified with different concentrations of Sb(III) and Sb(V). Also, we performed the determination of Sb(III) in a sample of a Sb-based drug utilized in the treatment of leishmaniasis. The results show that Sb(III) can be separated from high concentrations of Sb(V), since recoveries in the range of 81–110% were obtained in the analysis of the samples. The method presented limits of detection and quantification of 0.6 and 2µgL−1, respectively, for Sb(III) and 1 and 3µgL−1 for Sb(V), respectively.

Speciation Analysis of Antimony and Arsenic in Soil and Remediation of Antimony and Arsenic in Contaminated Soils

Antimony and arsenic are recognized to be toxic carcinogens. With the development of chemical industry, antimony and arsenic pollution problems are becoming more and more serious in soil. This paper described speciation analysis of antimony and arsenic in soil in the latest technical progress. Speciation analysis of arsenic and antimony which use joint techniques and non joint techniques are summarized. This paper also introduced various remediation technologies for antimony and arsenic contaminated soil. Finally, the trend for future technical development in remediation of antimony and arsenic in contaminated soils and speciation analysis is prospected.

Speciation analysis of antimony in water samples via combined nano-sized TiO2 colloid Preconcentration and AFS analysis

A method for the speciation of Sb was developed using nano-sized TiO2 colloids preconcentration and HG-AFS as a determination technique.

Arsenic and antimony speciation analysis in the environment using hyphenated techniques to inductively coupled plasma mass spectrometry: a review

Elemental speciation involves the separation and quantification of different oxidation states or chemical forms of a particular trace element. Trace metals exhibit widely different toxicities depending on their elemental species in the environment. On the other hand, inductively coupled plasma mass spectrometry (ICP-MS) is considered to be the method of choice for elemental analysis for several reasons. In this review, the speciation analysis of arsenic and antimony in environmental samples using ICP-MS detection is described. In this sense, the use of ICP-MS coupled with various separation techniques (e.g., HPLC, CE, GC, etc.) for the purpose of elemental speciation has recently gained a lot of attention.

Development of a non-chromatographic method for the speciation analysis of inorganic antimony in mushroom samples by hydride generation atomic fluorescence spectrometry

A simple and sensitive method has been developed for the direct determination of toxic species of antimony in mushroom samples by hydride generation atomic fluorescence spectrometry (HG AFS). The determination of Sb(III) and Sb(V) was based on the efficiency of hydride generation employing NaBH 4, with and without a previous KI reduction, using proportional equations corresponding to the two different measurement conditions. The extraction efficiency of total antimony and the stability of Sb(III) and Sb(V) in different extraction media (nitric, sulfuric, hydrochloric, acetic acid, methanol and ethanol) were evaluated. Results demonstrated that, based on the extraction yield and the stability of extracts, 0.5 mol L − 1 H 2SO 4 proved to be the best extracting solution for the speciation analysis of antimony in mushroom samples. The limits of detection of the developed methodology were 0.6 and 1.1 ng g − 1 for Sb(III) and Sb(V), respectively. The relative standard derivation was 3.8% (14.7 ng g − 1 ) for Sb(V) and 5.1% (4.6 ng g − 1 ) for Sb(III). The recovery values obtained for Sb(III) and Sb(V) varied from 94 to 106% and from 98 to 105%, respectively. The method has been applied to determine Sb(III), Sb(V) and total Sb in five different mushroom samples; the Sb(III) content varied from 4.6 to 11.4 ng g − 1 and Sb(V) from 14.7 to 21.2 ng g − 1 . The accuracy of the method was confirmed by the analysis of a certified reference material of tomato leaves.

On-line redox speciation analysis of antimony using l-proline immobilized on controlled pore glass and hydride generation inductively coupled plasma optical emission spectrometry for detection

l-proline was immobilized on controlled pore glass to study the ability of this material for the separation and preconcentration of Sb(III) and Sb(V). The substrate was packed in a minicolumn and incorporated in a flow injection system. The effluents of the on-line solid phase extraction (before and after elution) were directly coupled to the hydride generation inductively coupled plasma optical emission spectrometry system. The effect of pH, sample (and eluent) volume, flow rates of sample loading and elution on separation of Sb(III) e Sb(V) were evaluated. Our experiments demonstrated that Sb(V) was not retained and it was selectively determined during the loading step, while retained Sb(III) was determined after elution. The proposed system was also used for the selective preconcentration of Sb(III). In this case, a preconcentration factor of 11 and a limit of detection of 90 ng L −1 for Sb(III) were achieved when 8 mL of sample were loaded into the column. The speciation analysis of inorganic Sb in river water and effluent samples was performed using the proposed method. The values obtained for total Sb (obtained by sum of Sb(III) and Sb(V)) were in good agreement with expected values. Recoveries of Sb(III) and Sb(V) in the river water Standard Reference Material 1640 (from National Institute of Standard and Technology) and spiked river waters were between 83 and 111%.

Analytical techniques and methods used for antimony speciation analysis in biological matrices

Reports of antimony speciation analysis in biological matrices are so far limited. More specifically, only inorganic antimony (V) and antimony (III), mono-, di- and tri-methylantimony species, along with four complexes of SbV with lactate and citrate ligands, and two complexes of SbIII with glutathione have been so far identified. The limited progress may partly be attributed to the lack of suitable analytical methodologies. The main problems and challenges faced are (1) to achieve quantitative Sb extraction from solid biological materials, (2) species instability and their preservation during sample processing and analysis, (3) low chromatographic recovery of Sb from chromatographic columns with increased potential for species conversion when using stronger eluting mobile phases, and (4) trace level Sb species present at too low concentrations for molecular mass spectrometric identification. In the present article the hitherto used analytical methods and techniques are reviewed, with emphasis on identifying their main limitations, as well as highlighting recent breakthroughs. Re-assessing some of our current practises seems appropriate if we want to further advance the Sb speciation field, especially concerning the identification of Sb-complexes. Because of the generally low extractability, future antimony speciation studies may have to also rely on solid state analytical methods. In the case of sufficient extractability further advances in new separation methods are urgently required in order to achieve high column recoveries and maintain intact Sb species for further detection.

Determination of total antimony and inorganic antimony species by hydride generation in situ trapping flame atomic absorption spectrometry: a new way to (ultra)trace speciation analysis

The analytical performance of non-chromatographic coupled hydride generation, integrated atom trap (HG-IAT) atomizer flame absorption spectrometry (FAAS) systems were evaluated for the speciation analysis of antimony in environmental samples. Antimony, using formation of stibine (SbH3) vapors were atomized in an air–acetylene flame-heated IAT. A new design of HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements (a water-cooled single silica tube, double-slotted quartz tube or an “integrated trap”) was investigated. For the estimation of Sb(III) and Sb(V) concentrations in samples, the difference between the analytical sensitivities of the absorbance signals obtained for antimony hydride without and with previous treatment of samples with L-cysteine can be used. The concentration of Sb(V) was calculated by the difference between total Sbtot and Sb(III). A dramatic improvement in detection limit was achieved compared with that obtained using either of the atom trapping techniques, presented above, separately. This novel approach decreases the detection limit down to low pg mL–1 levels. The concentration detection limit, defined as 3 times the blank standard deviation (3sigma), was 0.2 ng mL–1. For a 120 s in situ pre-concentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 550 fold for Sb, using hydride generation-atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed by RSD, was 8.0% (n = 6) for Sb. The designs studied include slotted tube, water-cooled single silica tube and integrated atom traps. Reference and real sample materials were analyzed. The accuracy of the method was verified by the use of certified reference materials (NIST SRM 2704 Buffalo River Sediment, SRM 2710 Montana Soil, SRM 1633a Coal Fly Ash, SRM 1575 Pine Needles, SRM 1643e Trace Elements in Water) and by aqueous standard calibration technique (solutions). The measured Sb content, in reference materials, were in satisfactory agreement with the certified values. The hyphenated technique was applied for antimony determinations in soil, sediment, coal fly ash, sewage and river water.

Non-chromatographic hydride generation atomic spectrometric techniques for the speciation analysis of arsenic, antimony, selenium, and tellurium in water samples—a review

Hydride generation (HG) coupled with AAS, ICP–AES, and AFS techniques for the speciation analysis of As, Sb, Se, and Te in environmental water samples is reviewed. Careful control of experimental conditions, offline/online sample pretreatment methods employing batch, continuous and flow-injection techniques, and cryogenic trapping of hydrides enable the determination of various species of hydride-forming elements without the use of chromatographic separation. Other non-chromatographic approaches include solvent extraction, ion exchange, and selective retention by microorganisms. Sample pretreatment, pH dependency of HG, and control of NaBH4/HCl concentration facilitate the determination of As(III), As(V), monomethylarsonate (MMA), and dimethylarsinate (DMA) species. Inorganic species of arsenic are dominant in terrestrial waters, whereas inorganic and methylated species are reported in seawater. Selenium and tellurium speciation analysis is based on the hydrides generation only from the tetravalent state. Se(IV) and Se(VI) are the inorganic selenium species mostly reported in environmental samples, whereas speciation of tellurium is rarely reported. Antimony speciation analysis is based on the slow kinetics of hydride formation from the pentavalent state and is mainly reported in seawater samples.

Speciation analysis of antimony in marine biota by HPLC-(UV)-HG-AFS: Extraction procedures and stability of antimony species

Speciation analysis of antimony in marine biota is not well documented, and no specific extraction procedure of antimony species from algae and mollusk samples can be found in the literature. This work presents a suitable methodology for the speciation of antimony in marine biota (algae and mollusk samples). The extraction efficiency of total antimony and the stability of Sb(III), Sb(V) and trimethylantimony(V) in different extraction media (water at 25 and 90 °C, methanol, EDTA and citric acid) were evaluated by analyzing the algae Macrosystis integrifolia (0.55 ± 0.04 μg Sb g −1) and the mollusk Mytilus edulis (0.23 ± 0.01 μg Sb g −1). The speciation analysis was performed by anion exchange liquid chromatography (post-column photo-oxidation) and hydride generation atomic fluorescence spectrometry as detection system (HPLC-(UV)-HG-AFS). Results demonstrated that, based on the extraction yield and the stability, EDTA proved to be the best extracting solution for the speciation analysis of antimony in these matrices. The selected procedure was applied to antimony speciation in different algae samples collected from the Chilean coast. Only the inorganic Sb(V) and Sb(III) species were detected in the extracts. In all analyzed algae the sum of total antimony extracted (determined in the extracts after digestion) and the antimony present in the residue was in good agreement with the total antimony concentration determined by HG-AFS. However, in some extracts the sum of antimony species detected was lower than the total extracted, revealing the presence of unknown antimony species, possibly retained on the column or not detected by HPLC-(UV)-HG-AFS. Further work must be carried out to elucidate the identity of these unknown species of antimony.

Speciation analysis of antimony in extracts of size-classified volcanic ash by HPLC–ICP-MS

Although there is concern about the presence of toxic elements and their species in environmental matrices, for example water, sediment, and soil, speciation analysis of volcanic ash has received little attention. Antimony, in particular, an emerging element of environmental concern, has been less studied than other potentially toxic trace elements. In this context, a study was undertaken to assess the presence of inorganic Sb species in ash emitted from the Copahue volcano (Argentina). Antimony species were extracted from size-classified volcanic ash (<36 microm, 35-45 microm, 45-150 microm, and 150-300 microm) by use of 1 mol L(-1) citrate buffer at pH 5. Antimony(III) and (V) in the extracts were separated and quantified by high-performance liquid chromatography combined on-line with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Antimony species concentrations (microg g(-1)) in the four fractions varied from 0.14 to 0.67 for Sb(III) and from 0.02 to 0.03 for Sb(V). The results reveal, for the first time, the occurrence of both inorganic Sb species in the extractable portion of volcanic ash. Sb(III) was always the predominant species.