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Bodur S, Öner M, Erarpat S, Bakırdere S. Determination of selenite and selenomethionine in kefir grains by reversed-phase high-performance liquid chromatography-inductively coupled plasma-optical emission spectrometry. J Sep Sci 2021; 44:3031-3040. [PMID: 34102001 DOI: 10.1002/jssc.202100359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/29/2021] [Accepted: 06/04/2021] [Indexed: 11/08/2022]
Abstract
A new and efficient reversed-phase high-performance liquid chromatography-inductively coupled plasma-optical emission spectrometry method was developed for the simultaneous separation and determination of SeO3 2- and seleno-dl-methionine in kefir grains. For the system, limits of detection and quantitation values for SeO3 2- and seleno-dl-methionine were calculated as 0.52/1.73 mg/kg (as Se) and 0.26/0.87 mg/kg (as Se), respectively. After performing the system analytical performance, recovery experiment was done for kefir grains and percent recovery results for SeO3 2- and seleno-dl-methionine were calculated as 98.4 ± 0.8% and 93.6 ± 1.0%, respectively. It followed by the feeding studies that the kefir grains were exposed to three different concentrations of SeO3 2- (20, 30, and 50 mg/kg) for approximately 4 days at room temperature to investigate the conversion/non-conversion of SeO3 2- to seleno-dl-methionine. Next, the fed grains were extracted with tetramethylammonium hydroxide pentahydrate solution (20%, w/w) and then sent to the developed system. There was no detectable seleno-dl-methionine found in fed kefir grains at different concentrations of SeO3 2- while inorganic or elemental selenium in the fed kefir grains was determined between 1579.5 - 3116.0 mg/kg (as Se). Selenium species in the kefir grains samples was found in the form of SeO3 2- proved by using an anion exchange column.
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Affiliation(s)
- Süleyman Bodur
- Department of Chemistry, Faculty of Art and Science, Yıldız Technical University, Esenler, İstanbul, Turkey
| | - Miray Öner
- Department of Chemistry, Faculty of Art and Science, Yıldız Technical University, Esenler, İstanbul, Turkey
| | - Sezin Erarpat
- Department of Chemistry, Faculty of Art and Science, Yıldız Technical University, Esenler, İstanbul, Turkey
| | - Sezgin Bakırdere
- Department of Chemistry, Faculty of Art and Science, Yıldız Technical University, Esenler, İstanbul, Turkey.,Turkish Academy of Sciences (TÜBA), Çankaya, Ankara, Turkey
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Grygoyć K, Jabłońska-Czapla M. Development of a Tellurium Speciation Study Using IC-ICP-MS on Soil Samples Taken from an Area Associated with the Storage, Processing, and Recovery of Electrowaste. Molecules 2021; 26:2651. [PMID: 33946621 PMCID: PMC8124937 DOI: 10.3390/molecules26092651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 11/18/2022] Open
Abstract
The optimization and validation of a methodology for determining and extracting inorganic ionic Te(VI) and Te(IV) forms in easily-leached fractions of soil by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (IC-ICP-MS) were studied. In this paper, the total concentration of Te, pH, and red-ox potential were determined. Ions were successfully separated in 4 min on a Hamilton PRPX100 column with 0.002 mg/kg and 0.004 mg/kg limits of detection for Te(VI) and Te(IV), respectively. Soil samples were collected from areas subjected to the influence of an electrowaste processing and sorting plant. Sequential chemical extraction of soils showed that tellurium was bound mainly with sulphides, organic matter, and silicates. Optimization of soil extraction allowed 20% average extraction efficiency to be obtained, using 100 mM citric acid as the extractant. In the tested soil samples, both tellurium species were present. In most cases, the soils contained a reduced Te form, or the concentrations of both species were similar.
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Affiliation(s)
| | - Magdalena Jabłońska-Czapla
- Institute of Environmental Engineering Polish Academy of Sciences, M. Sklodowskiej-Curie 34 St., 41-819 Zabrze, Poland;
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Simultaneous and highly sensitive determination of selenium and tellurium species in environmental samples by on-line ionic liquid based in-situ solvent formation microextraction with hydride generation atomic fluorescence spectrometry detection. Talanta 2021; 222:121460. [PMID: 33167201 DOI: 10.1016/j.talanta.2020.121460] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/18/2020] [Accepted: 07/23/2020] [Indexed: 12/17/2022]
Abstract
A novel on-line preconcentration and speciation analysis method for the simultaneous determination of inorganic Se and Te species is presented in this work. The methodology is based on the on-line formation of a hydrophobic ionic liquid (IL) directly in the liquid sample stream of a flow injection system, thus achieving an efficient and rapid extraction of the analytes complexed with ammonium pyrrolidine dithiocarbamate into the finely dispersed extractant droplets, that were then retained in a column filled with cotton. A full study of the chemical and hydrodynamical parameters was developed, including the right selection of the IL used as extractant and its concentration, pH, complexing reagent, sample and ion-exchange reagent volumes and column design. Additionally, a miniaturized external hydride generator was adapted to the spectrometer in order to increase the sensitivity of the atomic fluorescence measurements using only 250 μL of 5 mol L-1 HNO3 in methanol as eluent. The analytical figures of merit obtained for 15 mL of sample included sensitivity enhancement factors of 71, 70, 49 and 40 for Te(IV), Te(VI), Se(IV) and Se(VI), respectively, and limits of detection of 1.8 ng L-1 for both Te species, 2.6 ng L-1 for Se(IV) and 3.2 ng L-1 for Se(VI). After optimization, the method was successfully applied for the analysis of environmental samples: soils and sediments, as well as sea, river, underground and tap water.
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Wu X, Guo X, Zhang L. Fabrication of Porous Zirconia Microspheres as an Efficient Adsorbent for Removal and Recovery of Trace Se(IV) and Te(IV). Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b04288] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xianqi Wu
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
| | - Xingjia Guo
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
| | - Lei Zhang
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
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Wojcieszek J, Szpunar J, Lobinski R. Speciation of technologically critical elements in the environment using chromatography with element and molecule specific detection. Trends Analyt Chem 2018. [DOI: 10.1016/j.trac.2017.09.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Sen BK, Tiwari S, Deb MK, Pervez S. Determination of Selenium by Single-Drop Microextraction and Diffuse Reflectance Infrared Spectroscopy. ANAL LETT 2016. [DOI: 10.1080/00032719.2016.1229786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Bhupendra K. Sen
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, India
| | - Swapnil Tiwari
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, India
| | - Manas K. Deb
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, India
| | - Shamsh Pervez
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, India
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Marcinkowska M, Barałkiewicz D. Multielemental speciation analysis by advanced hyphenated technique - HPLC/ICP-MS: A review. Talanta 2016; 161:177-204. [PMID: 27769396 DOI: 10.1016/j.talanta.2016.08.034] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/08/2016] [Accepted: 08/11/2016] [Indexed: 01/24/2023]
Abstract
Speciation analysis has become an invaluable tool in human health risk assessment, environmental monitoring or food quality control. Another step is to develop reliable multielemental speciation methodologies, to reduce costs, waste and time needed for the analysis. Separation and detection of species of several elements in a single analytical run can be accomplished by high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC/ICP-MS). Our review assembles articles concerning multielemental speciation determination of: As, Se, Cr, Sb, I, Br, Pb, Hg, V, Mo, Te, Tl, Cd and W in environmental, biological, food and clinical samples analyzed with HPLC/ICP-MS. It addresses the procedures in terms of following issues: sample collection and pretreatment, selection of optimal conditions for elements species separation by HPLC and determination using ICP-MS as well as metrological approach. The presented work is the first review article concerning multielemental speciation analysis by advanced hyphenated technique HPLC/ICP-MS.
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Affiliation(s)
- Monika Marcinkowska
- Department of Trace Element Analysis by Spectroscopy Method, Faculty of Chemistry, Adam Mickiewicz University in Poznań, 89b Umultowska Street, 61-614 Poznań, Poland
| | - Danuta Barałkiewicz
- Department of Trace Element Analysis by Spectroscopy Method, Faculty of Chemistry, Adam Mickiewicz University in Poznań, 89b Umultowska Street, 61-614 Poznań, Poland.
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Nayanova EV, Sergeev GM, Elipasheva EV. Selective photometric determination of low conentrations of selenium(IV) and selenium(VI) in bottled drinking water. JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1134/s1061934816040067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Chen YW, Alzahrani A, Deng TL, Belzile N. Valence properties of tellurium in different chemical systems and its determination in refractory environmental samples using hydride generation - Atomic fluorescence spectroscopy. Anal Chim Acta 2015; 905:42-50. [PMID: 26755135 DOI: 10.1016/j.aca.2015.11.035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 11/20/2015] [Accepted: 11/24/2015] [Indexed: 11/24/2022]
Abstract
Using HG - AFS as a powerful tool to study valence transformations of Te, we found that, in presence of HCl and at high temperature, Te can form volatile species and be lost during sample digestion and pre-reduction steps. It was also noticed that the chemical valences of Te can be modified under different chemical and digestion conditions and even by samples themselves with certain matrices. KBr can reduce Te(VI) to Te(IV) in 3.0 M HCl at 100 °C, but when HNO3 was >5% (v/v) in solution, Br2 was formed and caused serious interference to Te measurements. HCl alone can also pre-reduce Te(VI) to Te(IV), only when its concentration was ≥6.0 M (100 °C for 15min). Among 10 studied chemical elements, only Cu(2+) caused severe interference. Thiourea is an effective masking agent only when Cu(2+) concentration is equal or lower than 10 mg/L. Chemical reagents, chemical composition of sample, as well as the modes of digestion can greatly affect Te valences, reagent blanks and analytical precisions. A protocol of 2-step-digestion followed by an elimination of HF is proposed to minimize reagent blank and increase the signal/noise ratios. It is important to perform a preliminary test to confirm whether a pre-reduction step is necessary; this is especially true for samples with complex matrices such as those with high sulfide content. The analytical detection limits of this method in a pure solution and a solid sample were 100 ng/L and 0.10 ± 0.02 μg/g, respectively.
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Affiliation(s)
- Yu-Wei Chen
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | - Ali Alzahrani
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
| | - Tian-Long Deng
- College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, China
| | - Nelson Belzile
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada; Cooperative Freshwater Ecology Unit, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
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Peng H, Zhang N, He M, Chen B, Hu B. Simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by 3-(2-aminoethylamino) propyltrimethoxysilane modified multi-wall carbon nanotubes packed microcolumn solid phase extraction and ICP-MS. Talanta 2014; 131:266-72. [PMID: 25281102 DOI: 10.1016/j.talanta.2014.07.054] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 11/25/2022]
Abstract
Speciation analysis of inorganic arsenic, chromium and selenium in environmental waters is of great significance for the monitoring of environmental pollution. In this work, 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) functionalized multi-wall carbon nanotubes (MWCNTs) were synthesized and employed as the adsorbent for simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by microcolumn solid-phase extraction (SPE)-inductively coupled plasma mass spectrometry (ICP-MS). It was found that As(V), Cr(VI) and Se(VI) could be selectively adsorbed on the microcolumn packed with AAPTS-MWCNTs adsorbent at pH around 2.2, while As(III), Cr(III) and Se(IV) could not be retained at this pH and passed through the microcolumn directly. Total inorganic arsenic, chromium and selenium was determined after the oxidation of As(III), Cr(III) and Se(IV) to As(V), Cr(VI) and Se(VI) with 10.0 μmol L(-1) KMnO4. The assay of As(III), Cr(III) and Se(IV) was based on subtracting As(V), Cr(VI) and Se(VI) from the total As, Cr and Se, respectively. Under the optimized conditions, the detection limits of 15, 38 and 16 ng L(-1) with the relative standard deviations (RSDs) of 7.4, 2.4 and 6.2% (c=1 µg L(-1), n=7) were obtained for As(V), Cr(VI) and Se(VI), respectively. The developed method was validated by analyzing four Certified Reference Materials, rainwater, Yangtze River and East Lake waters.
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Affiliation(s)
- Hanyong Peng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Nan Zhang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Man He
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Beibei Chen
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Bin Hu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
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Ahn JY, Kwon HS, Pak YN. Quantification of seleno proteins in Korean blood serum using solid phase extraction and affinity chromatography-inductively coupled plasma/mass spectrometry. ANALYTICAL SCIENCE AND TECHNOLOGY 2014. [DOI: 10.5806/ast.2014.27.2.92] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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Rapid and sensitive determination of tellurium in soil and plant samples by sector-field inductively coupled plasma mass spectrometry. Talanta 2013; 116:181-7. [PMID: 24148390 DOI: 10.1016/j.talanta.2013.05.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/08/2013] [Accepted: 05/09/2013] [Indexed: 11/23/2022]
Abstract
In this work, we report a rapid and highly sensitive analytical method for the determination of tellurium in soil and plant samples using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Soil and plant samples were digested using Aqua regia. After appropriate dilution, Te in soil and plant samples was directly analyzed without any separation and preconcentration. This simple sample preparation approach avoided to a maximum extent any contamination and loss of Te prior to the analysis. The developed analytical method was validated by the analysis of soil/sediment and plant reference materials. Satisfactory detection limits of 0.17 ng g(-1) for soil and 0.02 ng g(-1) for plant samples were achieved, which meant that the developed method was applicable to studying the soil-to-plant transfer factor of Te. Our work represents for the first time that data on the soil-to-plant transfer factor of Te were obtained for Japanese samples which can be used for the estimation of internal radiation dose of radioactive tellurium due to the Fukushima Daiichi Nuclear Power Plant accident.
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Yildirim E, Akay P, Arslan Y, Bakirdere S, Ataman O. Tellurium speciation analysis using hydride generation in situ trapping electrothermal atomic absorption spectrometry and ruthenium or palladium modified graphite tubes. Talanta 2012. [DOI: 10.1016/j.talanta.2012.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Floor GH, Iglesías M, Román-Ross G, Corvini PFX, Lenz M. Selenium speciation in acidic environmental samples: application to acid rain-soil interaction at Mount Etna volcano. CHEMOSPHERE 2011; 84:1664-1670. [PMID: 21621241 DOI: 10.1016/j.chemosphere.2011.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 05/02/2011] [Accepted: 05/04/2011] [Indexed: 05/30/2023]
Abstract
Speciation plays a crucial role in elemental mobility. However, trace level selenium (Se) speciation analyses in aqueous samples from acidic environments are hampered due to adsorption of the analytes (i.e. selenate, selenite) on precipitates. Such solid phases can form during pH adaptation up till now necessary for chromatographic separation. Thermodynamic calculations in this study predicted that a pH<4 is needed to prevent precipitation of Al and Fe phases. Therefore, a speciation method with a low pH eluent that matches the natural sample pH of acid rain-soil interaction samples from Etna volcano was developed. With a mobile phase containing 20mM ammonium citrate at pH 3, selenate and selenite could be separated in different acidic media (spiked water, rain, soil leachates) in <10 min with a LOQ of 0.2 μg L(-1) using (78)Se for detection. Applying this speciation analysis to study acid rain-soil interaction using synthetic rain based on H(2)SO(4) and soil samples collected at the flanks of Etna volcano demonstrated the dominance of selenate over selenite in leachates from samples collected close to the volcanic craters. This suggests that competitive behavior with sulfate present in acid rain might be a key factor in Se mobilization. The developed speciation method can significantly contribute to understand Se cycling in acidic, Al/Fe rich environments.
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Affiliation(s)
- Geerke H Floor
- Department of Chemistry, University of Girona, Campus de Montilivi s/n, 17071 Girona, Spain.
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Tsai CY, Jiang SJ. Microwave-assisted extraction and ion chromatography dynamic reaction cell inductively coupled plasma mass spectrometry for the speciation analysis of arsenic and selenium in cereals. ANAL SCI 2011; 27:271-6. [PMID: 21415509 DOI: 10.2116/analsci.27.271] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An ion chromatography dynamic reaction cell inductively coupled plasma mass spectrometric (IC-DRC-ICP-MS) method for the speciation of arsenic and selenium compounds is described. Chromatographic separation was performed in a gradient elution mode using 0.5 mmol L(-1) ammonium citrate in 1% methanol (pH 4.5) and 15 mmol L(-1) ammonium citrate in 1% methanol (pH 8.0). The potentially interfering (38)Ar(40)Ar(+) and (40)Ar(40)Ar(+) at selenium masses of m/z 78 and 80 were reduced in intensity by approximately 3 orders of magnitude by using 1.0 mL min(-1) CH(4) as a reactive cell gas in the DRC. Arsenic was determined as the adduct ion (75)As(12)CH(2)(+) at m/z 89. The detection limits of the procedure were in the ranges of 0.006-0.009 ng As mL(-1) and 0.009-0.03 ng Se mL(-1), respectively. This method has been applied to determine various arsenic and selenium compounds in cereal samples. The accuracy of the method has been verified by comparing the sum of the concentrations of individual species obtained by the present procedure with the total concentration of elements. The arsenic and selenium compounds were quantitatively extracted with a Protease XIV and α-amylase solution in a microwave field at 70°C during a period of 30 min. The spike recoveries were in the range of 94-105% for all determinations.
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Affiliation(s)
- Chia-Ying Tsai
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
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Michalski R, Jabłonska M, Szopa S, Łyko A. Application of Ion Chromatography with ICP-MS or MS Detection to the Determination of Selected Halides and Metal/Metalloids Species. Crit Rev Anal Chem 2011. [DOI: 10.1080/10408347.2011.559438] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17
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Ghasemi E, Najafi NM, Raofie F, Ghassempour A. Simultaneous speciation and preconcentration of ultra traces of inorganic tellurium and selenium in environmental samples by hollow fiber liquid phase microextraction prior to electrothermal atomic absorption spectroscopy determination. JOURNAL OF HAZARDOUS MATERIALS 2010; 181:491-496. [PMID: 20542634 DOI: 10.1016/j.jhazmat.2010.05.040] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 04/26/2010] [Accepted: 05/10/2010] [Indexed: 05/29/2023]
Abstract
A simple and effective speciation and preconcentration method based on hollow fiber liquid phase microextraction (HF-LPME) was developed for simultaneous separation of trace inorganic tellurium and selenium in environmental samples prior to electrothermal atomic absorption spectroscopy (ETAAS) determination. The method involves the selective extraction of the Te (IV) and Se (IV) species by HF-LPME with the use of ammonium pyrrolidinecarbodithioate (APDC) as the chelating agent. The complex compounds were extracted into 10 microL of toluene and the solutions were injected into a graphite furnace for the determination of Te (IV) and Se (IV). To determine the total tellurium and selenium in the samples, first Te (VI) and Se (VI) were reduced to Te (IV) and Se (IV), and then the microextraction method was performed. The experimental parameters of HF-LPME were optimized using a central composite design after a 2(n-1) fractional factorial experimental design. Under optimum conditions, enrichment factors of up to 520 and 480 were achieved for Te (IV) and Se (IV), respectively. The detection limits were 4 ng L(-1) with 3.5% RSD (n=5, c=2.0 microg L(-1)) for Te (IV) and 5 ng L(-1) with 3.1% RSD for Se (IV). The applicability of the developed technique was evaluated by application to spiked, environmental water and soil samples.
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Affiliation(s)
- Ensieh Ghasemi
- Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran, Iran
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Open-label, phase I dose-escalation study of sodium selenate, a novel activator of PP2A, in patients with castration-resistant prostate cancer. Br J Cancer 2010; 103:462-8. [PMID: 20648008 PMCID: PMC2939789 DOI: 10.1038/sj.bjc.6605798] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Background: Angiogenesis is fundamental to the progression of many solid tumours including prostate cancer. Sodium selenate is a small, water-soluble, orally bioavailable activator of PP2A phosphatase with anti-angiogenic properties. Methods: This was a dose-escalation phase I study in men with asymptomatic, chemotherapy-naïve, castration-resistant prostate cancer. The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included establishing the safety, tolerability and pharmacokinetic profile. Results: A total of 19 patients were enrolled. The MTD was 60 mg per day. Dose-limiting toxicity (fatigue and diarrhoea) was observed at 90 mg per day. The most frequently reported treatment-related adverse events across all treatment cohorts were nausea, diarrhoea, fatigue, muscle spasms, alopecia and nail disorders. No grade 4 toxicities were observed and there were no deaths on study. Linear pharmacokinetics was observed. One patient had a PSA response >50%. Median time to PSA progression (for non-responders) was 14.2 weeks. Mean PSA doubling time increased during the main treatment phase from 2.18 months before trial to 3.85 months. Conclusion: Sodium selenate is well tolerated at a dose of 60 mg per day with modest single-agent efficacy similar to other anti-angiogenic agents. Further trials in combination with conventional cytotoxic regimens are warranted.
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Cai TS, Li SX. Sensitivity enhancement using nanometer silica particles on the surface of a quartz cell in mercury and selenium determination by vapor generation atomic absorption spectrometry. Mikrochim Acta 2010. [DOI: 10.1007/s00604-010-0398-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wallschläger D, Feldmann J. Formation, Occurrence, Significance, and Analysis of Organoselenium and Organotellurium Compounds in the Environment. ORGANOMETALLICS IN ENVIRONMENT AND TOXICOLOGY 2010. [DOI: 10.1039/9781849730822-00319] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Among all environmentally-relevant trace elements, selenium has one of the most diverse organic chemistries. It is also one of the few trace elements that may biomagnify in food chains under certain conditions. Yet, the exact chemical forms of selenium involved in the uptake into organisms and transfer to higher trophic levels, as well as the biochemical mechanisms that lead to their subsequent metabolism in organisms, are still not well understood. This is in part due to the analytical challenges associated with measuring the myriad of discrete Se species occurring in organisms. While there are generalized concepts of selenium metabolism, there is a lack of conclusive analytical evidence supporting the existence of many postulated intermediates. Likewise, there is a disconnect between the major selenium species encountered in abiotic compartments (waters, soils, and sediment), and those found in organisms, which renders the qualitative and quantitative description of the bioaccumulation process uncertain. Here, we summarize the knowledge on important selenium and tellurium species in all environmental compartments, and identify gaps and uncertainties in the existing body of knowledge, with emphasis on problems associated with past and current analytical methodology.
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Affiliation(s)
- Dirk Wallschläger
- Environmental & Resource Sciences Program and Department of Chemistry, Trent University 1600 West Bank Dr. Peterborough ON K9J 7B8 Canada
| | - Jörg Feldmann
- Trace Element Speciation Laboratory (TESLA), College of Physical Science, University of Aberdeen Meston Walk Aberdeen Scotland AB24 3UE UK
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do Nascimento PC, Jost CL, de Carvalho LM, Bohrer D, Koschinsky A. Voltammetric determination of Se(IV) and Se(VI) in saline samples--studies with seawater, hydrothermal and hemodialysis fluids. Anal Chim Acta 2009; 648:162-6. [PMID: 19646579 DOI: 10.1016/j.aca.2009.06.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 04/17/2009] [Accepted: 06/23/2009] [Indexed: 10/20/2022]
Abstract
Determination of Se(IV) and Se(VI) in high saline media was investigated by cathodic stripping voltammetry (CSV). The voltammetric method was applied to assay selenium in seawater, hydrothermal and hemodialysis fluids. The influence of ionic strength on selenium determination is discussed. The CSV method was based on the co-electrodeposition of Se(IV) with Cu(II) ions and Se(VI) determined by difference after sample UV-irradiation for photolytic selenium reduction. UV-irradiation was also used as sample pre-treatment for organic matter decomposition. Detection limit of 0.030 microg L(-1) (240 s deposition time) and relative standard deviation (RSD) of 6.19% (n=5) for 5.0 microg L(-1) of Se(IV) were calculated. Linear calibration range for selenium was observed from 1.0 to 100.0 microg L(-1). Concerning the pre-treatment step, best results were obtained by using 60 min UV-irradiation interval in H(2)O(2)/HCl medium. Se(VI) was reduced to the Se(IV) electroactive species with recoveries between 91.7% and 112.9%. Interferents were also investigated.
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Affiliation(s)
- Paulo C do Nascimento
- Departamento de Química, Universidade Federal de Santa Maria, 97105-970 Santa Maria, RS, Brazil.
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Hollow fiber liquid phase microextraction followed by high performance liquid chromatography for determination of ultra-trace levels of Se(IV) after derivatization in urine, plasma and natural water samples. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:1758-64. [DOI: 10.1016/j.jchromb.2009.04.039] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2008] [Revised: 04/21/2009] [Accepted: 04/26/2009] [Indexed: 11/24/2022]
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Michalke B, Grill P, Berthele A. A method for low volume and low Se concentration samples and application to paired cerebrospinal fluid and serum samples. J Trace Elem Med Biol 2009; 23:243-50. [PMID: 19747619 DOI: 10.1016/j.jtemb.2009.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 05/11/2009] [Accepted: 06/09/2009] [Indexed: 10/20/2022]
Abstract
The well-known beneficial health effects of Se have demanded the development of rapid and accurate methods for its analysis. A flow injection (FI) method with inductively coupled plasma mass spectrometry (ICP-MS) as a selenium-selective detector was optimized. Flow injection was carried out using a Knauer 1100 smartline inert series liquid chromatograph coupled with a Perkin Elmer DRC II ICP-mass spectrometer. For sample injection a Perkin Elmer electronic valve equipped with a 25microL sample loop was employed. Before measurement, standards or samples were administered with 1microg/L rhodium as internal standard for correction of changes in detector response according to changes in sample electrolyte concentration. The method characterization parameters are: LOD (3sigma criterion): 26ng/L, LOQ (10sigma criterion): 86ng/L, linearity: 0.05->10microg/L, r(2)=0.9999, serial or day-to-day precision at 2microg/L: 4.48% or 5.6%. Accuracy was determined by (a) recovery experiments (CSF spiked with 2microg/L Se); (b) comparison of FI-ICP-MS measurement with graphite furnace atomic absorption (GFAAS) measurements of 1:10 diluted serum samples; (c) Se determination in urine and serum control materials. Recovery (a) was 101.4%, measurement comparison with GFAAS (b) showed 98.8% (5 serum samples, 1:10 diluted in the range of 0.5-1.3microg/L, compared to GFAAS determination, which was set to 100%), and accuracy was 96.8% or 105.6% for the serum or urine control material. Analysis time per sample was short and typically below 2min for the complete measurement, including sample introduction, sample-line purge and quadruplicate Se determination. This method was used to determine Se in cerebrospinal fluid (CSF) and plasma (here parallel to GFAAS) in 35 paired serum and CSF samples. Se determination gave values in the range of 42-130microg/L for serum and 1.63-6.66microg/L for CSF. The median for Se in 35 individual CSF samples was 3.28microg/L, the mean (+/-SD) was 3.67 (1.35)microg/L, whilst for individual serum samples the median was 81microg/L and the mean (+/-SD) was 85 (26)microg/L. When relating the paired Se concentrations of CSF samples to respective serum samples it turned out that Se-CSF (behind blood brain barrier (BBB)) is independent on Se-serum concentration (before BBB).
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Affiliation(s)
- Bernhard Michalke
- Helmholtz Center Munich - German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
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OGRA Y. Toxicometallomics for Research on the Toxicology of Exotic Metalloids Based on Speciation Studies. ANAL SCI 2009; 25:1189-95. [DOI: 10.2116/analsci.25.1189] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Yasumitsu OGRA
- Laboratory of Chemical Toxicology and Environmental Health, Showa Pharmaceutical University
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