The Experts below are selected from a list of 141 Experts worldwide ranked by ideXlab platform
Arndt Schimmelmann - One of the best experts on this subject based on the ideXlab platform.
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optimization of on line hydrogen stable isotope ratio measurements of halogen and sulfur bearing organic compounds using elemental analyzer chromium high temperature conversion isotope ratio mass spectrometry ea cr htc irms
Rapid Communications in Mass Spectrometry, 2017Co-Authors: Matthias Gehre, Julian Renpenning, Heike Geilmann, Haiping Qi, Tyler B Coplen, Steffen Kummel, Natalija Ivdra, Willi A Brand, Arndt SchimmelmannAbstract:Rationale Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems. Methods The EA-Cr/HTC reactor was substantially modified for the conversion of halogen- and sulfur-bearing samples. The performance of the novel conversion setup for solid and liquid samples was monitored and optimized using a simultaneously operating dual-detection system of IRMS and ion trap MS. The method with several variants in the reactor, including the addition of Manganese Metal chips, was evaluated in three laboratories using EA-Cr/HTC-IRMS (on-line method) and compared with traditional uranium-reduction-based conversion combined with manual dual-inlet IRMS analysis (off-line method) in one laboratory. Results The modified EA-Cr/HTC reactor setup showed an overall H2-recovery of more than 96% for all halogen- and sulfur-bearing organic compounds. All results were successfully normalized via two-point calibration with VSMOW-SLAP reference waters. Precise and accurate hydrogen isotopic analysis was achieved for a variety of organics containing F-, Cl-, Br-, I-, and S-bearing heteroelements. The robust nature of the on-line EA-Cr/HTC technique was demonstrated by a series of 196 consecutive measurements with a single reactor filling. Conclusions The optimized EA-Cr/HTC reactor design can be implemented in existing analytical equipment using commercially available material and is universally applicable for both heteroelement-bearing and heteroelement-free organic-compound classes. The sensitivity and simplicity of the on-line EA-Cr/HTC-IRMS technique provide a much needed tool for routine hydrogen-isotope source tracing of organic contaminants in the environment. Copyright © 2016 John Wiley & Sons, Ltd.
Matthias Gehre - One of the best experts on this subject based on the ideXlab platform.
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optimization of on line hydrogen stable isotope ratio measurements of halogen and sulfur bearing organic compounds using elemental analyzer chromium high temperature conversion isotope ratio mass spectrometry ea cr htc irms
Rapid Communications in Mass Spectrometry, 2017Co-Authors: Matthias Gehre, Julian Renpenning, Heike Geilmann, Haiping Qi, Tyler B Coplen, Steffen Kummel, Natalija Ivdra, Willi A Brand, Arndt SchimmelmannAbstract:Rationale Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems. Methods The EA-Cr/HTC reactor was substantially modified for the conversion of halogen- and sulfur-bearing samples. The performance of the novel conversion setup for solid and liquid samples was monitored and optimized using a simultaneously operating dual-detection system of IRMS and ion trap MS. The method with several variants in the reactor, including the addition of Manganese Metal chips, was evaluated in three laboratories using EA-Cr/HTC-IRMS (on-line method) and compared with traditional uranium-reduction-based conversion combined with manual dual-inlet IRMS analysis (off-line method) in one laboratory. Results The modified EA-Cr/HTC reactor setup showed an overall H2-recovery of more than 96% for all halogen- and sulfur-bearing organic compounds. All results were successfully normalized via two-point calibration with VSMOW-SLAP reference waters. Precise and accurate hydrogen isotopic analysis was achieved for a variety of organics containing F-, Cl-, Br-, I-, and S-bearing heteroelements. The robust nature of the on-line EA-Cr/HTC technique was demonstrated by a series of 196 consecutive measurements with a single reactor filling. Conclusions The optimized EA-Cr/HTC reactor design can be implemented in existing analytical equipment using commercially available material and is universally applicable for both heteroelement-bearing and heteroelement-free organic-compound classes. The sensitivity and simplicity of the on-line EA-Cr/HTC-IRMS technique provide a much needed tool for routine hydrogen-isotope source tracing of organic contaminants in the environment. Copyright © 2016 John Wiley & Sons, Ltd.
Liu Zhihong - One of the best experts on this subject based on the ideXlab platform.
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Hazard-free treatment of electrolytic Manganese residue and recovery of Manganese using low temperature roasting-water washing process
'Elsevier BV', 2022Co-Authors: He Shichao, Wilson, Benjamin P., Lundström Mari, Liu ZhihongAbstract:A combined low-temperature-roasting and water-washing process is investigated as a hazard-free method to treat electrolytic Manganese residue (EMR) and recover Manganese. In this study, the phase transformation characteristics and a thermodynamics analysis of the low temperature roasting process of EMR are evaluated. In addition, the effects of temperature and time on the phase transformation of EMR in the roasting process and the washing characteristics of roasted EMR samples are also investigated. Results reveal that some unstable phases within EMR are transformed into more stable phases depending on the treatment time/temperature conditions used and EMR roasted for 60 min at 600 °C (R60min/600°C) exhibit the highest rate of Manganese recovery, 67.12 %. After 25 minutes of deionized water washing, the concentration of Manganese in solution from R60min/600°C material become stable, whereas after 6 washing cycles the concentration of Manganese in the solution is < 0.005 g/L. The R60min/600°C material with three wash cycles results in a Manganese-water solution concentration that is suitable for use in electrolytic Manganese Metal production. Finally, toxicity leaching tests show that the concentrations of ions present in the leaching solution are all lower than the regulatory limits mandated by the Chinese Integrated Wastewater Discharge Standard GB 8978-1996.Peer reviewe
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Hazard-free treatment of electrolytic Manganese residue and recovery of Manganese using low temperature roasting-water washing process
'Elsevier BV', 2022Co-Authors: He Shichao, Wilson, Benjamin P., Lundström Mari, Liu ZhihongAbstract:A combined low-temperature-roasting and water-washing process is investigated as a hazard-free method to treat electrolytic Manganese residue (EMR) and recover Manganese. In this study, the phase transformation characteristics and a thermodynamics analysis of the low temperature roasting process of EMR are evaluated. In addition, the effects of temperature and time on the phase transformation of EMR in the roasting process and the washing characteristics of roasted EMR samples are also investigated. Results reveal that some unstable phases within EMR are transformed into more stable phases depending on the treatment time/temperature conditions used and EMR roasted for 60 min at 600 °C (R 60min/600°C) exhibit the highest rate of Manganese recovery, 67.12 %. After 25 min of deionized water washing, the concentration of Manganese in solution from R 60min/600°C material become stable, whereas after 6 washing cycles the concentration of Manganese in the solution is < 0.005 g/L. The R 60min/600°C material with three wash cycles results in a Manganese-water solution concentration that is suitable for use in electrolytic Manganese Metal production. Finally, toxicity leaching tests show that the concentrations of ions present in the leaching solution are all lower than the regulatory limits mandated by the Chinese Integrated Wastewater Discharge Standard GB 8978−1996.Peer reviewe
Subrat Kumar Padhy - One of the best experts on this subject based on the ideXlab platform.
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effect of sodium alkyl sulfates on electrodeposition of Manganese Metal from sulfate solutions in the presence of sodium metabisulphite
Hydrometallurgy, 2018Co-Authors: Subrat Kumar Padhy, Bankim Ch Tripathy, Akram AlfantaziAbstract:Abstract Electrodeposition of Manganese in the presence of selenium compounds results in high current yield. However, selenium compounds are environmentally toxic and hence their use in Manganese electrodeposition should be controlled. The main objective of the present study was to avoid the use of selenium compounds during electrodeposition of Manganese without compromising with quality and current yield. Thus in the present study electrolytic Manganese Metal (EMM) has been produced from aqueous Manganese(II) sulfate solutions in the presence of sodium alkyl sulfates (SAS) as organic additives. The alkyl sulfates used in the present study are sodium octyl sulfate (SOS), sodium lauryl sulfate (SLS) and sodium tetradecyl sulfate (STS). It was found that addition of SOS at a concentration of 20 mg·L−1 was most effective in increasing the cathodic current efficiency from 59% to 67% and in presence of 10 mg·L−1 SLS 63.5% cathodic efficiency was obtained. Further in presence of these additives bright and smooth Manganese deposits were resulted. It was also observed that increase in alkyl chain length in the additives used in this work affected the deposit morphology and current yield adversely, however in all the cases α–Manganese with (330, 411) as the most preferred plane of orientations were produced. Polarization of cathode takes place in presence of all the organic anionic additives used in the current study and the degree of polarization increases with increase in concentration and chain length of additives.
Tyler B Coplen - One of the best experts on this subject based on the ideXlab platform.
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optimization of on line hydrogen stable isotope ratio measurements of halogen and sulfur bearing organic compounds using elemental analyzer chromium high temperature conversion isotope ratio mass spectrometry ea cr htc irms
Rapid Communications in Mass Spectrometry, 2017Co-Authors: Matthias Gehre, Julian Renpenning, Heike Geilmann, Haiping Qi, Tyler B Coplen, Steffen Kummel, Natalija Ivdra, Willi A Brand, Arndt SchimmelmannAbstract:Rationale Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems. Methods The EA-Cr/HTC reactor was substantially modified for the conversion of halogen- and sulfur-bearing samples. The performance of the novel conversion setup for solid and liquid samples was monitored and optimized using a simultaneously operating dual-detection system of IRMS and ion trap MS. The method with several variants in the reactor, including the addition of Manganese Metal chips, was evaluated in three laboratories using EA-Cr/HTC-IRMS (on-line method) and compared with traditional uranium-reduction-based conversion combined with manual dual-inlet IRMS analysis (off-line method) in one laboratory. Results The modified EA-Cr/HTC reactor setup showed an overall H2-recovery of more than 96% for all halogen- and sulfur-bearing organic compounds. All results were successfully normalized via two-point calibration with VSMOW-SLAP reference waters. Precise and accurate hydrogen isotopic analysis was achieved for a variety of organics containing F-, Cl-, Br-, I-, and S-bearing heteroelements. The robust nature of the on-line EA-Cr/HTC technique was demonstrated by a series of 196 consecutive measurements with a single reactor filling. Conclusions The optimized EA-Cr/HTC reactor design can be implemented in existing analytical equipment using commercially available material and is universally applicable for both heteroelement-bearing and heteroelement-free organic-compound classes. The sensitivity and simplicity of the on-line EA-Cr/HTC-IRMS technique provide a much needed tool for routine hydrogen-isotope source tracing of organic contaminants in the environment. Copyright © 2016 John Wiley & Sons, Ltd.
