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141 results on '"FELDMANN, JOERG"'

102. Selenium and tellurium concentrations of Carboniferous British coals.

Author

Bullock, Liam A., Parnell, John, Feldmann, Joerg, Armstrong, Joseph G., Henn, Alessandra S., Mesko, Marcia F., Mello, Paola A., Flores, Erico M.M., and Somerville, I. D.

Subjects
SELENIUM, TELLURIUM, COAL, MASS spectrometry, THERMAL coal, TRACE elements, VOLCANOLOGY
Abstract

Standard mode and collision/reaction cell mass spectroscopy methods have been utilized in order to overcome spectral interferences and provide ultra‐low quantification of selenium (Se) and tellurium (Te) in British Carboniferous coals for the first time. The accurate detection of Se and Te in coals is becoming increasingly important, as coals and pyrite have been identified as potentially significant trace element sources. The mean Se concentration of British coals bear comparison to that of world coals, with anomalous Se content (concentrations above 4 mg/kg) across westerly exposures, often coinciding with high sulphur (S) content and visible pyrite. New Te data for British coals gives a mean concentration of 0.02 mg/kg, with anomalous Te in Ayrshire. There is a positive correlation in the Te/Se ratio across the sample set. The close relationship between Se and Te, as well as Se–Te with both early syngenetic and later cleat‐filling pyrite, confirms an important role for sulphides in Se and Te sequestration in British coals. The high Se‐Bowland Shale and/or Ordovician volcanics may have provided the trace element source for British coals of similar or younger age. Regional intrusive activity (shallow tabular intrusions or more extensive plutons) and episodes of intense deformation can alter the thermal maturity of coals and may have driven the movement of trace element‐rich fluids through strata, locally enriching coals in Se and Te. [ABSTRACT FROM AUTHOR]

Published
2019
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106. Importance of ICPMS for speciation analysis is changing: future trends for targeted and non-targeted element speciation analysis.

Author

Feldmann, Joerg, Raab, Andrea, and Krupp, Eva M.

Subjects
*INDUCTIVELY coupled plasma mass spectrometry, *SPECIATION analysis, *INORGANIC compounds, *ISOTOPE dilution analysis, *TRIBUTYLTIN
Abstract

This article is aimed at researchers interested in organic molecules which contain a heteroatom but who have never considered using inductively coupled plasma mass spectrometry (ICPMS) or who have used ICPMS for years and developed numerous methods for analysis of target elemental species. We try to illustrate (1) that ICPMS has been very useful for speciation analysis of metal(loid) target species and that there is now a trend to replace the costly detector with cheaper detection systems for routine target analysis, and (2) that ICPMS has been used and will be used even more in the future for non-targeted analysis of elements which are not normally associated with ICPMS analysis, such as non-metals such as sulfur, phosphorus, chlorine and fluorine. [ABSTRACT FROM AUTHOR]

Published
2018
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120. Arsenic Shoot-Grain Relationships in Field Grown Rice Cultivars

Author

Norton, Gareth J, primary, Islam, M. Rafiqul, additional, Duan, Guilan, additional, Lei, Ming, additional, Zhu, Yongguan, additional, Deacon, Claire M, additional, Moran, Annette C, additional, Islam, Shofiqul, additional, Zhao, Fang-Jie, additional, Stroud, Jacqueline L., additional, McGrath, Steve P., additional, Feldmann, Joerg, additional, Price, Adam H, additional, and Meharg, Andrew A, additional

Published
2010
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122. Grain Unloading of Arsenic Species in Rice

Author

Carey, Anne-Marie, primary, Scheckel, Kirk G., additional, Lombi, Enzo, additional, Newville, Matt, additional, Choi, Yongseong, additional, Norton, Gareth J., additional, Charnock, John M., additional, Feldmann, Joerg, additional, Price, Adam H., additional, and Meharg, Andrew A., additional

Published
2009
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123. Environmental and Genetic Control of Arsenic Accumulation and Speciation in Rice Grain: Comparing a Range of Common Cultivars Grown in Contaminated Sites Across Bangladesh, China, and India

Author

Norton, Gareth J., primary, Duan, Guilan, additional, Dasgupta, Tapash, additional, Islam, M. Rafiqul, additional, Lei, Ming, additional, Zhu, Yongguan, additional, Deacon, Claire M., additional, Moran, Annette C., additional, Islam, Shofiqul, additional, Zhao, Fang-Jie, additional, Stroud, Jacqueline L., additional, McGrath, Steve P., additional, Feldmann, Joerg, additional, Price, Adam H., additional, and Meharg, Andrew A., additional

Published
2009
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126. Geographical Variation in Total and Inorganic Arsenic Content of Polished (White) Rice

Author

Meharg, Andrew A., primary, Williams, Paul N., additional, Adomako, Eureka, additional, Lawgali, Youssef Y., additional, Deacon, Claire, additional, Villada, Antia, additional, Cambell, Robert C. J., additional, Sun, Guoxin, additional, Zhu, Yong-Guan, additional, Feldmann, Joerg, additional, Raab, Andrea, additional, Zhao, Fang-Jie, additional, Islam, Rafiqul, additional, Hossain, Shahid, additional, and Yanai, Junta, additional

Published
2009
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133. Quantitative and Qualitative Trapping of Volatile Methylated Selenium Species Entrained through Nitric Acid.

Author

WINKEL, LENNY, FELDMANN, JOERG, and MEHARG, ANDREW A.

Subjects
*SELENIUM & the environment, *METHYL groups, *NITRIC acid, *CHEMICAL speciation, *ENVIRONMENTAL chemistry techniques, *EVALUATION, *LABORATORY equipment & supplies
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. [ABSTRACT FROM AUTHOR]

Published
2010
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141. Selenopeptides and elemental selenium in Thunbergia alata after exposure to selenite: quantification method for elemental selenium

Author

Joerg Feldmann, William A. Maher, Fatai Adigun Aborode, Simon Foster, Andrea Raab, Eva M. Krupp, Enzo Lombi, Aborode, Fatai Adigun, Raab, Andrea, Foster, Simon, Lombi, Enzo, Maher, William, Krupp, Eva M., and Feldmann, Joerg

Subjects
inorganic chemicals, Spectrometry, Mass, Electrospray Ionization, Formic acid, Inorganic chemistry, Biophysics, chemistry.chemical_element, Selenic Acid, Selenious Acid, Plant Roots, Biochemistry, Selenate, Biomaterials, Selenium, chemistry.chemical_compound, Biotransformation, Acanthaceae, Thunbergia alata, Selenomethionine, Chromatography, High Pressure Liquid, Sodium sulfite, biology, Selenocysteine, Extraction (chemistry), Metals and Alloys, food and beverages, biology.organism_classification, chemistry, Chemistry (miscellaneous), selenite, Nuclear chemistry
Abstract

Three month old Thunbergia alata were exposed for 13 days to 10 μM selenite to determine the biotransformation of selenite in their roots. Selenium in formic acid extracts (80 ± 3%) was present as selenopeptides with Se-S bonds and selenium-PC complexes (selenocysteinyl-2-3-dihydroxypropionyl-glutathione, seleno-phytochelatin2, seleno-di-glutathione). An analytical method using HPLC-ICPMS to detect and quantify elemental selenium in roots of T. alata plants using sodium sulfite to quantitatively transform elemental selenium to selenosulfate was also developed. Elemental selenium was determined as 18 ± 4% of the total selenium in the roots which was equivalent to the selenium not extracted using formic acid extraction. The results are in an agreement with the XAS measurements of the exposed roots which showed no occurrence of selenite or selenate but a mixture of selenocysteine and elemental selenium. Refereed/Peer-reviewed

Published
2015

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