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Trimethylselenonium ion determination in human urine by high-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry optimization of the hydride generation step. Anal Bioanal Chem 2023; 415:317-326. [PMID: 36348039 DOI: 10.1007/s00216-022-04408-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/10/2022]
Abstract
This work describes the intricacies of the determination of the trimethylselenonium ion (TMSe) in human urine via high-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS). By definition, this technique requires that the separated TMSe can be online converted into a volatile compound. Literature data for the determination of TMSe via the hydride generation technique are contradictory; i.e., some authors claim that direct formation of volatile compounds is possible under reduction with NaBH4, whereas others reported that a digestion step is mandatory prior to conversion. We studied and optimized the conditions for online conversion by varying the mobile phase composition (pyridine, phosphate, and acetate), testing different reaction coils, and optimizing the hydride generation conditions, although technically no hydride (H2Se) is formed but a dimethylselenide (DMSe). The optimized conditions were used for the analysis of 64 urine samples of 16 (unexposed) volunteers and the determination of low amounts of TMSe (LOD = 0.2 ng mL-1). Total (specific gravity-corrected) selenium concentrations in the urine samples ranged from 7.9 ± 0.7 to 29.7 ± 5.0 ng mL-1 for individual volunteers. Four volunteers were characterized as TMSe producers (hINMT genotype GA) and 12 were non-producers (hINMT genotype GG). Urine of TMSe producers contained 2.5 ± 1.7 ng mL-1 of TMSe, compared to 0.2 ± 0.2 ng mL-1 for non-producers.
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2
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Huang T, Yuan G. Hollow Zinc Oxide Microflowers for Selective Preconcentration of Selenium Ions in Natural Water. CURR ANAL CHEM 2020. [DOI: 10.2174/1573411015666191122120331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Selenium’s popularity in a wide variety of products and industries means
that it has, unfortunately, become a common environmental pollutant, particularly from sources such
as industrial wastewater discharge and agricultural runoff.
Objective:
Quantification of the selenium (IV) ion content of natural water sources via atomic fluorescence
spectrophotometry (AFS) was performed using hollow ZnO microflowers as the enriched
materials. The hollow ZnO microflowers were prepared via a hydrothermal method with polystyrene
(PS) microspheres as the template.
Methods:
Since the pH of the selenium (IV) solution is known to influence the degree of adsorption
onto the sorbent, both the acidity of adsorption and elution were studied at various pH values to obtain
the adsorption isotherm and adsorption capacity of the sorbent. AFS was used to quantify the
amount of selenium ion that was present in the samples. The structure of the hollow ZnO microflowers
was characterized using XRD, SEM, and TEM characterization methodologies.
Results:
When the pH was between 6.0 and 7.0, the percentage of Se (IV) adsorption was as high as
93%. It was found that the amount of Se (IV) that was eluted from the sorbent exceeded 96% with
5.0 mL of a 0.01 mol L−1 NaOH solution over the course of 10 minutes. The maximum adsorption
capacity was 31.5, 31.8, and 32.0 mg·g−1 at 273, 333, and 353 K, respectively.
Conclusion:
The LOD for Se (IV) detection via enrichment was achieved at 0.006 μg L−1 with a linear
range between 0.1 and 200 μg L−1. Thus, this method is applicable to the analysis of natural water
samples and GBW(E)080394.
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Affiliation(s)
- Ting Huang
- Department of Chemistry and Chemical Engineering, Ankang University, Ankang, Shaanxi 725000, China
| | - Guanghui Yuan
- Department of Chemistry and Chemical Engineering, Ankang University, Ankang, Shaanxi 725000, China
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3
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Xiong J, Xu K, Hou X, Wu P. AuNCs-Catalyzed Hydrogen Selenide Oxidation: Mechanism and Application for Headspace Fluorescent Detection of Se(IV). Anal Chem 2019; 91:6141-6148. [PMID: 30990020 DOI: 10.1021/acs.analchem.9b00738] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The excellent fluorescence property of Au nanoclusters (AuNCs) has received great attention for various chemosensing and biorelated applications, but the sample matrix is still an important problem that causes undesirable fluorescence variation. On the one hand, hydride generation (HG) is an effective strategy to separate the target analyte from the complex sample matrices, but the implementation of HG with AuNC-based fluorescent assays was not realized. On the other hand, due to the ultrasmall size of AuNCs and good catalytic performance of Au, AuNCs are also featuring intriguing catalytic applications. Herein, we proposed a new type of AuNC-based fluorescence assay for Se(IV) detection, in which hydride generation of Se(IV) was coupled with the fluorescence/catalytic dual functions of AuNCs. In a batch hydride generation mode, Se(IV) was first converted to volatile H2Se. When it spread in the headspace to contact with AuNCs supported paper, AuNC-catalyzed oxidation of H2Se by O2 to yield elemental selenium occurred, which further deposited on the surface of AuNCs to induce fluorescence quenching. The catalytic effect of AuNCs was studied in depth via both experimental and theoretical (density functional theory) investigations. Three main steps for H2Se oxidation were identified, with energy barriers in the presence of AuNCs significantly lower than those without. Benefiting from the reduced matrix interference by hydride generation and the unique catalysis/fluorescence of AuNCs, the proposed assay featured high selectivity, good sensitivity, and simplicity, with successful applications for selenium detection in real samples.
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Pagliano E, Campanella B, D'Ulivo A, Mester Z. Derivatization chemistries for the determination of inorganic anions and structurally related compounds by gas chromatography - A review. Anal Chim Acta 2018; 1025:12-40. [DOI: 10.1016/j.aca.2018.03.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 12/12/2022]
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5
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Maher W, Krikowa F, Foster S. Decomposition of six common selenium species found in animal tissues using microwave digestion with nitric acid and ICP-MS. Microchem J 2016. [DOI: 10.1016/j.microc.2015.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Determination of selenium in dietary supplements by optical emission spectrometry after alkaline dissolution and subsequent headspace solid phase microextraction. J Pharm Biomed Anal 2013; 74:268-72. [DOI: 10.1016/j.jpba.2012.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/06/2012] [Accepted: 11/07/2012] [Indexed: 11/22/2022]
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7
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Ai X, Wang Y, Hou X, Yang L, Zheng C, Wu L. Advanced oxidation using Fe3O4 magnetic nanoparticles and its application in mercury speciation analysis by high performance liquid chromatography-cold vapor generation atomic fluorescence spectrometry. Analyst 2013; 138:3494-501. [DOI: 10.1039/c3an00010a] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Xu S, Zheng M, Zhang X, Zhang J, Lee YI. Nano TiO2-based preconcentration for the speciation analysis of inorganic selenium by using ion chromatography with conductivity detection. Microchem J 2012. [DOI: 10.1016/j.microc.2011.10.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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9
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Li H, Luo Y, Li Z, Yang L, Wang Q. Nanosemiconductor-Based Photocatalytic Vapor Generation Systems for Subsequent Selenium Determination and Speciation with Atomic Fluorescence Spectrometry and Inductively Coupled Plasma Mass Spectrometry. Anal Chem 2012; 84:2974-81. [DOI: 10.1021/ac3001995] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Huamin Li
- Department
of Chemistry and the Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, and ‡State Key Laboratory of Marine
Environmental Science, Xiamen University, Xiamen 361005, China
| | - Yacui Luo
- Department
of Chemistry and the Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, and ‡State Key Laboratory of Marine
Environmental Science, Xiamen University, Xiamen 361005, China
| | - Zhaoxin Li
- Department
of Chemistry and the Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, and ‡State Key Laboratory of Marine
Environmental Science, Xiamen University, Xiamen 361005, China
| | - Limin Yang
- Department
of Chemistry and the Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, and ‡State Key Laboratory of Marine
Environmental Science, Xiamen University, Xiamen 361005, China
| | - Qiuquan Wang
- Department
of Chemistry and the Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, and ‡State Key Laboratory of Marine
Environmental Science, Xiamen University, Xiamen 361005, China
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Qin HB, Zhu JM, Su H. Selenium fractions in organic matter from Se-rich soils and weathered stone coal in selenosis areas of China. CHEMOSPHERE 2012; 86:626-33. [PMID: 22115469 DOI: 10.1016/j.chemosphere.2011.10.055] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 10/12/2011] [Accepted: 10/28/2011] [Indexed: 05/19/2023]
Abstract
A high degree of association between Selenium (Se) and organic matter has been demonstrated in natural environments, but Se fractions and speciation in organic matter is unclear. In this study, a method for quantifying organic matter associated with Se (OM-Se) was developed to investigate Se fractions in organic matter in Se-rich soils and weathered stone coal from Enshi, China, where Se poisoning of humans and livestock has been documented. Initially, Se was extracted using water and a phosphate buffer. Subsequently, OM-Se was extracted using NaOH, and then speciated into Se associated with fulvic acids (FA-Se) and humic acids (HA-Se). Both FA-Se and HA-Se were further speciated into the weakly bound and strongly bound fractions using a customized hydride generation reactor. The results show that FA-Se (1.91-479 mg kg(-1)) is the predominant form of Se in all Se-rich soils and the weathered stone coal samples, accounting for more than 62% of OM-Se (3.07-484 mg kg(-1)). Weakly bound FA-Se (1.33-450 mg kg(-1)) was prevalent in the total FA-Se, while weakly bound HA-Se (0.62-26.2 mg kg(-1)) was variable in the total HA-Se (1.15-32.5 mg kg(-1)). These data indicate that OM-Se could play a significant source and sink role in the biogeochemical cycling of Se in the supergene environment. Weakly bound FA-Se seems to act as a potential source for bioavailable Se, whereas strongly bound HA-Se is a possible OM-Se sink which is not readily transformed into bioavailable Se.
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Affiliation(s)
- Hai-bo Qin
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
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11
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Winkel LHE, Johnson CA, Lenz M, Grundl T, Leupin OX, Amini M, Charlet L. Environmental selenium research: from microscopic processes to global understanding. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:571-9. [PMID: 22129299 DOI: 10.1021/es203434d] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Selenium is a natural trace element that is of fundamental importance to human health. The extreme geographical variation in selenium concentrations in soils and food crops has resulted in significant health problems related to deficient or excess levels of selenium in the environment. To deal with these kinds of problems in the future it is essential to get a better understanding of the processes that control the global distribution of selenium. The recent development of analytical techniques and methods enables accurate selenium measurements of environmental concentrations, which will lead to a better understanding of biogeochemical processes. This improved understanding may enable us to predict the distribution of selenium in areas where this is currently unknown. These predictions are essential to prevent future Se health hazards in a world that is increasingly affected by human activities.
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Affiliation(s)
- Lenny H E Winkel
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, P.O. Box 611, 8600 Duebendorf, Switzerland.
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12
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D’Ulivo A, Dědina J, Mester Z, Sturgeon RE, Wang Q, Welz B. Mechanisms of chemical generation of volatile hydrides for trace element determination (IUPAC Technical Report). PURE APPL CHEM 2011. [DOI: 10.1351/pac-rep-09-10-03] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aqueous-phase chemical generation of volatile hydrides (CHG) by derivatization with borane complexes is one of the most powerful and widely employed methods for determination and speciation analysis of trace and ultratrace elements (viz. Ge, Sn, Pb, As, Sb, Bi, Se, Te, Hg, Cd, and, more recently, several transition and noble metals) when coupled with atomic and mass spectrometric detection techniques. Analytical CHG is still dominated by erroneous concepts, which have been disseminated and consolidated within the analytical scientific community over the course of many years. The overall approach to CHG has thus remained completely empirical, which hinders possibilities for further development. This report is focused on the rationalization and clarification of fundamental aspects related to CHG: (i) mechanism of hydrolysis of borane complexes; (ii) mechanism of hydrogen transfer from the borane complex to the analytical substrate; (iii) mechanisms through which the different chemical reaction conditions control the CHG process; and (iv) mechanism of action of chemical additives and foreign species. Enhanced comprehension of these different mechanisms and their mutual influence can be achieved in light of the present state of knowledge. This provides the tools to explain the reactivity of a CHG system and contributes to the clarification of several controversial aspects and the elimination of erroneous concepts in CHG.
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Affiliation(s)
- Alessandro D’Ulivo
- 1National Research Council of Italy (C.N.R.), Institute of Chemistry of Organometallic Compounds, C.N.R., Via G. Moruzzi, 1 56124 Pisa, Italy
| | - Jiří Dědina
- 2Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno, Czech Republic
| | - Zoltan Mester
- 3Institute for National Measurement Standards, N.R.C. Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
| | - Ralph E. Sturgeon
- 3Institute for National Measurement Standards, N.R.C. Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
| | - Qiuquan Wang
- 4College of Chemistry and Chemical Engineering, Xiamen University, Key Laboratory of Analytical Sciences, Xiamen 361005, China
| | - Bernhard Welz
- 5Department of Chemistry, Universidade Federal de Santa Catarina, Florianòpolis-SC 88040-900, Brazil
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13
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Krittaphol W, McDowell A, Thomson CD, Mikov M, Fawcett JP. Biotransformation of L-selenomethionine and selenite in rat gut contents. Biol Trace Elem Res 2011; 139:188-96. [PMID: 20229173 DOI: 10.1007/s12011-010-8653-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 02/10/2010] [Indexed: 10/19/2022]
Abstract
L-selenomethionine (SeMet) and sodium selenite are widely used selenium nutritional supplements with potential benefit in preventing cancer. However, supplementation is not without risks of toxicity if intake is too high. The aim of the present study was to investigate SeMet and selenite metabolism in the gastrointestinal tract with particular focus on the formation of the volatile selenium excretion products, dimethylselenide (DMSe) and dimethyldiselenide (DMDSe). Adult male Wistar rats (n = 5) were euthanized, their intestinal tracts removed and the contents of jejunum, ileum, caecum and colon used to prepare 10% suspensions in saline. SeMet and selenite (0.5-0.6 mM) were then incubated with these suspensions at 37°C for 3 h. Caecum and colon contents were the most metabolically active towards SeMet with 30% and 15% metabolized over 3 h. DMDSe was the only volatile selenium metabolite detected accounting for 8.7 ± 1.3% of the selenium lost in caecum contents. Selenite was completely metabolized by caecum contents and 73% by colon contents under the same conditions forming DMSe (5.7 ± 0.9% of the selenium lost in caecum) and a precipitate of red amorphous elemental selenium. Based on previous literature and these results, we conclude that the gut microbiota contributes to the excretion of excess selenium through the production of methylated selenium compounds and elemental selenium.
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14
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Gammelgaard B, Jackson MI, Gabel-Jensen C. Surveying selenium speciation from soil to cell--forms and transformations. Anal Bioanal Chem 2010; 399:1743-63. [PMID: 20953781 DOI: 10.1007/s00216-010-4212-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 09/08/2010] [Indexed: 12/21/2022]
Abstract
The aim of this review is to present and evaluate the present knowledge of which selenium species are available to the general population in the form of food and common supplements and how these species are metabolized in mammals. The overview of the selenium sources takes a horizontal approach, which encompasses identification of new metabolites in yeast and food of plant and animal origin, whereas the survey of the mammalian metabolism takes a horizontal as well as a vertical approach. The vertical approach encompasses studies on dynamic conversions of selenium compounds within cells, tissues or whole organisms. New and improved sample preparation, separation and detection methods are evaluated from an analytical chemical perspective to cover the progress in horizontal speciation, whereas the analytical methods for the vertical speciation and the interpretations of the results are evaluated from a biological angle as well.
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Affiliation(s)
- Bente Gammelgaard
- Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
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15
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Winkel L, Feldmann J, Meharg AA. Quantitative and qualitative trapping of volatile methylated selenium species entrained through nitric acid. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:382-387. [PMID: 19950978 DOI: 10.1021/es902345m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Quantification and speciation of volatile selenium (Se) fluxes in remote areas has not been feasible previously, due to the absence of a simple and easily transportable trapping technique that preserves speciation. This paper presents a chemo-trapping method with nitric acid (HNO3) for volatile Se species, which preserves speciation of trapped compounds. The recovery and speciation of dimethylselenide (DMSe) and dimethyl diselenide (DMDSe) entrained through both concentrated nitric acid and hydrogen peroxide (H2O2) were compared by HPLC-ICP-MS and HPLC-HG-AFS analyses. It was demonstrated that trap reproducibility was better for nitric acid and a recovery of 65.2 +/- 1.9% for DMSe and 81.3 +/- 3.9% for DMDSe was found in nitric acid traps. HPLC-ES-MS identified dimethyl selenoxide (DMSeO) as the trapped product of DMSe. Methylseleninic acid (MSA) was identified to be the single product of DMDSe trapping. These oxidized derivatives have a high stability and low volatility, which makes nitric acid a highly attractive trapping liquid for volatile Se species and enables reconstruction of the speciation of those species. The presented trapping method is simple, quantifiable, reproducible, and robust and can potentially be applied to qualitatively and quantitatively study Se volatilization in a wide range of natural environments.
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Affiliation(s)
- Lenny Winkel
- Institute for Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU, UK.
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Peitzsch M, Kremer D, Kersten M. Microfungal alkylation and volatilization of selenium adsorbed by goethite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:129-135. [PMID: 20039743 DOI: 10.1021/es9006492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Selenium adsorbed in the oxyanionic form by Fe-oxides like goethite is considered of benefit for long-term stabilization of (79)Se under near field conditions of radionuclide waste disposal sites. However, microbe-mediated volatilization of the uranium fission product (79)Se has not yet been considered for risk assessment based on the use of the water-solid distribution coefficient K(D). We have performed incubation experiments in a ternary system selenium-microbe-goethite and show that mycobiota including the common black microfungi genera Alternaria alternata are capable of volatilizing the Se even if immobilized by goethite. The microfungi were incubated in a standardized nutrient broth suspension with 10 g L(-1) of the oxide target under defined conditions. Volatile organic selenium (VOSe) species formed in the head space of the culture flasks were sampled and measured directly by a cryotrapping cryofocusing gas chromatographic system coupled with ICP-MS detection (CT-CF-GC-ICP-MS). Alkylated VOSe species were found at the tens to hundreds ng m(-3) levels dominated by dimethyl selenide (DMSe) and dimethyl diselenide (DMDSe). The total amount of DMSe released into the 80-mL headspace volume within the 21 days of incubation was up to 1.12 +/- 0.17 nmol and 0.48 +/- 0.12 nmol for systems without and with goethite amendment, respectively. Alkylation rates of up to 0.1 mumol Se per day and g biomass cannot be neglected as a potential fission product mobilization pathway, unless the inherent radioactivity is proven to prevent any such microbial activity on the long-term. Otherwise it may lead to an onsite accumulation of (79)Se through evapoconcentration in the enclosed underground caverns.
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Affiliation(s)
- Mirko Peitzsch
- Geosciences Institute, Johannes Gutenberg-University, Mainz 55099, Germany
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17
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Matich AJ, McKenzie MJ, Brummell DA, Rowan DD. Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium. PHYTOCHEMISTRY 2009; 70:1098-1106. [PMID: 19570557 DOI: 10.1016/j.phytochem.2009.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 05/28/2009] [Accepted: 06/01/2009] [Indexed: 05/08/2023]
Abstract
Nicotiana tabacum L. (tobacco) plants were transformed to overexpress a selenocysteine methyltransferase gene from the selenium hyperaccumulator Astragalus bisulcatus (Hook.) A. Gray (two-grooved milkvetch), and an ATP-sulfurylase gene from Brassica oleracea L. var. italica (broccoli). Solvent extraction of leaves harvested from plants treated with selenate revealed five selenium-containing compounds, of which four were identified by chemical synthesis as 2-(methylseleno)acetaldehyde, 2,2-bis(methylseleno)acetaldehyde, 4-(methylseleno)-(2E)-nonenal, and 4-(methylseleno)-(2E,6Z)-nonadienal. These four compounds have not previously been reported in nature.
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Affiliation(s)
- Adam J Matich
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand.
| | - Marian J McKenzie
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - David A Brummell
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - Daryl D Rowan
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
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18
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The determination by gas chromatography with atomic emission detection of total sulfur in fuels used as forensic evidence. Forensic Sci Int 2007; 177:112-9. [PMID: 18160239 DOI: 10.1016/j.forsciint.2007.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 11/05/2007] [Accepted: 11/10/2007] [Indexed: 11/21/2022]
Abstract
In Japan, taxed diesel fuel from non-taxed fuel oil-A is illegally produced by removing coumarin, which is added as a non-taxed marker. The coumarin is removed using concentrated sulfuric acid and this produces a high viscosity and hazardous material, called "sulfuric acid pitch", as a by-product. This compound has a detrimental effect on the environment and is hazardous to humans. The actions have been associated with organized crime with the illegally gained taxes becoming financial bases. To discriminate legal and diesel oil from illegal product, the peak area ratio R(SC), the ratio of total sulfur to carbon (>C(14)), was used. R(SC) is calculated by the total areas of sulfur and carbon (>C(14)) from the gas chromatogram obtained by gas chromatography-atomic emission detection (GC-AED). Sulfur in legal diesel fuels is strictly regulated by a maximum limit, which was 50ppm (and is now 10ppm), but in the preparation of illegal diesel oil, in which coumarin is eliminated, sulfur cannot be removed. Therefore, the R(SC) of fuel oil-A and illegal fuel oil is over 15, whereas those for legal fuel oil and diesel fuel are under 2.0. Furthermore, these ratios do not change in weathering experiments. GC-AED was applied to an actual arson case and was found to be effective for the determination of total sulfur in trace amounts of accelerants detected in fire debris at the arson scene, and hence was effective for the characterization of the ignitable liquids used.
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Yin Y, Qiu J, Yang L, Wang Q. A new vapor generation system for mercury species based on the UV irradiation of mercaptoethanol used in the determination of total and methyl mercury in environmental and biological samples by atomic fluorescence spectrometry. Anal Bioanal Chem 2007; 388:831-6. [PMID: 17256110 DOI: 10.1007/s00216-007-1122-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 12/25/2006] [Accepted: 01/08/2007] [Indexed: 10/23/2022]
Abstract
A new vapor generation system for mercury (Hg) species based on the irradiation of mercaptoethanol (ME) with UV was developed to provide an effective sample introduction unit for atomic fluorescence spectrometry (AFS). Preliminary investigations of the mechanism of this novel vapor generation system were based on GC-MS and FT-IR studies. Under optimum conditions, the limits of determination for inorganic divalence mercury and methyl mercury were 60 and 50 pg mL(-1), respectively. Certified reference materials (BCR 463 tuna fish and BCR 580 estuarine sediment) were used to validate this new method, and the results agreed well with certified values. This new system provides an attractive alternative method of chemical vapor generation (CVG) of mercury species compared to other developed CVG systems (for example, the traditional KBH(4)/NaOH-acid system). To our knowledge, this is the first systematic report on UV/ME-based Hg species vapor generation and the determination of total and methyl Hg in environmental and biological samples using UV/ME-AFS.
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Affiliation(s)
- Yanmin Yin
- Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
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Regmi R, Milne BF, Feldmann J. Hydride generation activity of arsenosugars and thioarsenicals. Anal Bioanal Chem 2007; 388:775-82. [PMID: 17221238 DOI: 10.1007/s00216-006-1076-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 11/24/2006] [Accepted: 12/05/2006] [Indexed: 10/23/2022]
Abstract
The major arsenosugar compounds have been reported to be hydride-generation-active, however to a lesser extent in comparison with the inorganic arsenicals. We report here for the first time the identity and quantity of the volatile arsenicals generated by As-sugar-SO(3), As-sugar-SO(4), dimethylarsinoyl acetic acid and dimethylarsinoyl ethanol. Only one major volatile compound was identified for all four compounds studied: dimethylarsine. This means that the As-C bond to the longer carbon chain was cleaved during the hydride-generation process. Theoretical calculations at the RHF/6-31G(d,p) ab initio level confirm that this As-C bond is much weaker than the As-CH(3) bonds. Furthermore, it was revealed that the sulphur analogue of dimethylarsinic acid (DMAS ) is hydride-generation-active at pH 7 in contrast to dimethylarsinic acid, despite the fact that arsenic is also pentavalent. This has been substantiated by the calculation of the change in susceptibility of the arsenic towards nucleophilic attack when oxygen is replaced by sulphur. Hence, DMAS can easily be mistaken for a trivalent arsenic species.
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Affiliation(s)
- Rajendra Regmi
- Department of Chemistry, College of Physical Sciences, University of Aberdeen, Old Aberdeen, AB24 3UE, UK
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21
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Campillo N, Aguinaga N, Viñas P, López-García I, Hernández-Córdoba M. Gas chromatography with atomic emission detection for dimethylselenide and dimethyldiselenide determination in waters and plant materials using a purge-and-trap preconcentration system. J Chromatogr A 2005; 1095:138-44. [PMID: 16275294 DOI: 10.1016/j.chroma.2005.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Revised: 07/25/2005] [Accepted: 08/01/2005] [Indexed: 10/25/2022]
Abstract
Dimethylselenide (DMSe) and dimethyldiselenide (DMDSe) were determined in plant and water samples by capillary gas chromatography using microwave induced-plasma atomic emission spectrometry for detection. The analytes were leached from the solid samples into methanol by using an ultrasonic probe, and a portion of the extract was preconcentrated by means of a purge-and-trap system before being chromatographed. The analytes were directly purged from the water samples in the presence of 6% (v/v) methanol. Element-specific detection and quantification was carried out by monitoring the selenium (196 nm) emission line. Calibration curves were obtained by plotting peak area versus concentration and the correlation coefficients for linear calibration were 0.9999 for both analytes. Detection limits of 0.8 and 1.1 ng l(-1) were obtained for DMSe and DMDSe, respectively, for water samples. For plant materials, the detection limits calculated for 0.5 g samples were 0.3 and 0.4 ng g(-1) for DMSe and DMDSe, respectively. Concentration levels of DMSe ranging from 1.2 to 4.2 ng g(-1) were found in some of the plant materials analyzed. No DMDSe was found in any of the samples. The accuracy of the method was checked by analyzing different spiked water and plant samples.
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Affiliation(s)
- Natalia Campillo
- Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, Spain
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22
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Chen YW, Zhou XL, Tong J, Truong Y, Belzile N. Photochemical behavior of inorganic and organic selenium compounds in various aqueous solutions. Anal Chim Acta 2005. [DOI: 10.1016/j.aca.2005.03.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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23
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Zhang WB, Gan WE, Lin XQ. Electrochemical hydride generation atomic fluorescence spectrometry for the simultaneous determination of arsenic and antimony in Chinese medicine samples. Anal Chim Acta 2005. [DOI: 10.1016/j.aca.2005.03.050] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Moreno ME, Pérez-Conde C, Cámara C. The effect of the presence of volatile organoselenium compounds on the determination of inorganic selenium by hydride generation. Anal Bioanal Chem 2003; 375:666-72. [PMID: 12638051 DOI: 10.1007/s00216-003-1774-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2002] [Revised: 12/18/2002] [Accepted: 12/20/2002] [Indexed: 11/30/2022]
Abstract
As a result of microbiological activity it is possible to find dimethylselenium (DMSe) and dimethyldiselenium (DMDSe) in a wide type of environmental samples, such as soils, sediments, sewage sludges and plants where methylation can take place. Selenium determination by hydride-generation (HG) techniques requires its presence as Se(IV). Consequently, inorganic speciation by hydride generation techniques is done by first determining Se(IV) and then, after reduction of Se (VI) to Se(IV), the total selenium. Therefore, the concentration of Se (VI) is evaluated as the difference between total inorganic selenium and Se(IV). In the present work it could be demonstrated that DMSe and DMDSe are forming other volatile species by reaction with sodium borohydride, applying the same reduction condition as for inorganic selenium. These species are subsequently detected by several atomic techniques (atomic absorption AAS, atomic fluorescence AFS and inductively coupled plasma-mass spectrometry ICP-MS). The error that their presence can cause in determination of inorganic selenium has been evaluated. The magnitude of this error depends on the specific analytical detector used.The coupling of pervaporation-atomic fluorescence is proposed for the identification of these species and pervaporation-gas chromatography-atomic fluorescence for their individual quantification.
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Affiliation(s)
- M Eva Moreno
- Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
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25
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Chasteen TG, Bentley R. Biomethylation of selenium and tellurium: microorganisms and plants. Chem Rev 2003; 103:1-25. [PMID: 12517179 DOI: 10.1021/cr010210+] [Citation(s) in RCA: 263] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas G Chasteen
- Department of Chemistry, Sam Houston State University, Huntsville, Texas 77341, USA.
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