The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Robin M Black - One of the best experts on this subject based on the ideXlab platform.
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analysis of the sulphur mustard metabolites Thiodiglycol and Thiodiglycol sulphoxide in urine using isotope dilution gas chromatography ion trap tandem mass spectrometry
Journal of Chromatography B, 2007Co-Authors: James R Riches, Robert W Read, Robin M BlackAbstract:A sensitive method has been developed for the trace analysis of the sulphur mustard metabolite Thiodiglycol (TDG) in urine, and its oxidation product Thiodiglycol sulphoxide (TDGO) after reduction to Thiodiglycol. Thiodiglycol was extracted from urine by solid phase extraction onto a polymeric cartridge and, after isolation, converted to its bis-heptafluorobutyryl derivative with heptafluorobutyryl imidazole. An ion trap mass spectrometer in selected reaction monitoring mode detected spiked concentrations down to 0.2 ng/ml with a signal to noise ratio > 3:1. Urine, from human volunteers with no known exposure to sulphur mustard, contained detectable but very low concentrations (<0.2 ng/ml) of Thiodiglycol, consistent with previous observations using different methodologies. Combined concentrations of Thiodiglycol and Thiodiglycol sulphoxide were determined after reduction of the latter with titanium trichloride. In this case higher background levels (up to 3 ng/ml) were observed, consistent with the sulphoxide being the major excretion product of the two metabolites. The method was applied to urine samples, stored frozen for 13 years, from two casualties of accidental mustard poisoning. Levels of Thiodiglycol were 1 and 3 ng/ml, which increased to 78 and 104 ng/ml after treatment of the urine with titanium trichloride.
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improved methodology for the detection and quantitation of urinary metabolites of sulphur mustard using gas chromatography tandem mass spectrometry
Journal of Chromatography B: Biomedical Sciences and Applications, 1995Co-Authors: Robin M Black, Robert W ReadAbstract:Abstract Gas chromatography-tandem mass spectrometry (GC-MS-MS) with selected-reaction monitoring was applied to the analysis of urinary metabolites of sulphur mustard, derived from the β-lyase pathway and from hydrolysis. In the case of β-lyase metabolites, a limit of detection of 0.1 ng/ml was obtained, compared to 2–5 ng/ml using single stage GC-MS with selected-ion monitoring. GC-MS-MS methodology was less useful when applied to the analysis of Thiodiglycol bis(pentafluorobenzoate) using negative-ion chemical ionisation although selected-reaction chromatograms were cleaner than selected-ion chromatograms. The advantage of using GC-MS-MS was demonstrated by the detection of low levels of β-lyase metabolites in the urine of casualties who had been exposed to sulphur mustard.
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biological fate of sulphur mustard 1 1 thiobis 2 chloroethane identification of beta lyase metabolites and hydrolysis products in human urine
Xenobiotica, 1995Co-Authors: Robin M Black, Robert W ReadAbstract:1. Samples of urine from two human subjects accidentally exposed to sulphur mustard were analysed for metabolites derived from hydrolysis (Thiodiglycol, Thiodiglycol sulphoxide), conjugation with glutathione (1,1'-sulphonylbis [2-S-(N-acetylcysteinyl)ethane]) and from further metabolism of glutathione conjugates by the beta-lyase pathway (1,1-sulphonylbis[2-(methylsulphinyl)ethane], 1-methylsulphinyl-2-[2-(methylthio)ethylsulphonyl]ethane). 2. Thiodiglycol sulphoxide was excreted in much higher concentrations than Thiodiglycol, as was observed previously in rat exposed to sulphur mustard. However, the use of Thiodiglycol sulphoxide as a biological marker for sulphur mustard poisoning is limited by its presence at low concentrations in normal human urine. 3. beta-lyase metabolites were detected at concentrations comparable with those of Thiodiglycol sulphoxide. No background levels of beta-lyase metabolites have been detected in normal human urine, and they are proposed as unequivocal diagnostic and forensic indicators of sulphur mustard poisoning in man.
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application of gas chromatography mass spectrometry and gas chromatography tandem mass spectrometry to the analysis of chemical warfare samples found to contain residues of the nerve agent sarin sulphur mustard and their degradation products
Journal of Chromatography A, 1994Co-Authors: Robin M Black, Robert W Read, Raymond J Clarke, Michael T J ReidAbstract:Samples of clothing, grave debris, soil and munition fragments, collected from the Kurdish village of Birjinni, were analysed by GC-MS with selected ion monitoring (SIM) for traces of chemical warfare agents and their degradation products. Positive analyses were confirmed, where possible, by full scan mass spectra, or at low concentrations by additional GC-MS-SIM analysis using chemical ionisation, by higher resolution GC-MS-SIM, and by GC-tandem mass spectrometry using multiple reaction monitoring. Sulphur mustard and/or Thiodiglycol were detected in six soil samples; isopropyl methylphosphonic acid and methylphosphonic acid, the hydrolysis products of the nerve agent sarin, were detected in six different soil samples. Trace amounts of intact sarin were detected on a painted metal fragment associated with one of these soil samples. The results demonstrate the application of different GC-MS and GC-MS-MS techniques to the unequivocal identification of chemical warfare agent residues in the environment at concentrations ranging from low ppb to ppm (w/w). They also provide the first documented unequivocal identification of nerve agent residues in environmental samples collected after a chemical attack.
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application of headspace analysis solvent extraction thermal desorption and gas chromatography mass spectrometry to the analysis of chemical warfare samples containing sulphur mustard and related compounds
Journal of Chromatography A, 1993Co-Authors: Robin M Black, Robert W Read, Raymond J Clarke, David B Cooper, D UtleyAbstract:Abstract Samples of soil, munition fragments and wool, associated with a chemical warfare incident involving sulphur mustard, were analysed using headspace, solvent extraction and thermal desorption techniques combined with full scanning gas chromatography—mass spectrometry. Quantitative analysis was undertaken for sulphur mustard, mustard sulphoxide and Thiodiglycol, using solvent extraction and gas chromatography—mass spectrometry with selected ion monitoring. In a soil sample contaminated at ppm (w/w) levels all methods gave positive results for mustard and related compounds. Selected ion monitoring and thermal desorption were the more useful techniques at low ppb (w/w) levels. Cyclic decomposition products 1,4-thioxane and 1,4-dithiane appear to be useful indicators of mustard contamination when using thermal desorption analysis. The hydrolysis product Thiodiglycol and hydrolysis/elimination product 2-(vinylthio)ethanol appear to be useful indicators of mustard contamination in soil samples when employing extraction methods.
Robert W Read - One of the best experts on this subject based on the ideXlab platform.
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analysis of the sulphur mustard metabolites Thiodiglycol and Thiodiglycol sulphoxide in urine using isotope dilution gas chromatography ion trap tandem mass spectrometry
Journal of Chromatography B, 2007Co-Authors: James R Riches, Robert W Read, Robin M BlackAbstract:A sensitive method has been developed for the trace analysis of the sulphur mustard metabolite Thiodiglycol (TDG) in urine, and its oxidation product Thiodiglycol sulphoxide (TDGO) after reduction to Thiodiglycol. Thiodiglycol was extracted from urine by solid phase extraction onto a polymeric cartridge and, after isolation, converted to its bis-heptafluorobutyryl derivative with heptafluorobutyryl imidazole. An ion trap mass spectrometer in selected reaction monitoring mode detected spiked concentrations down to 0.2 ng/ml with a signal to noise ratio > 3:1. Urine, from human volunteers with no known exposure to sulphur mustard, contained detectable but very low concentrations (<0.2 ng/ml) of Thiodiglycol, consistent with previous observations using different methodologies. Combined concentrations of Thiodiglycol and Thiodiglycol sulphoxide were determined after reduction of the latter with titanium trichloride. In this case higher background levels (up to 3 ng/ml) were observed, consistent with the sulphoxide being the major excretion product of the two metabolites. The method was applied to urine samples, stored frozen for 13 years, from two casualties of accidental mustard poisoning. Levels of Thiodiglycol were 1 and 3 ng/ml, which increased to 78 and 104 ng/ml after treatment of the urine with titanium trichloride.
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improved methodology for the detection and quantitation of urinary metabolites of sulphur mustard using gas chromatography tandem mass spectrometry
Journal of Chromatography B: Biomedical Sciences and Applications, 1995Co-Authors: Robin M Black, Robert W ReadAbstract:Abstract Gas chromatography-tandem mass spectrometry (GC-MS-MS) with selected-reaction monitoring was applied to the analysis of urinary metabolites of sulphur mustard, derived from the β-lyase pathway and from hydrolysis. In the case of β-lyase metabolites, a limit of detection of 0.1 ng/ml was obtained, compared to 2–5 ng/ml using single stage GC-MS with selected-ion monitoring. GC-MS-MS methodology was less useful when applied to the analysis of Thiodiglycol bis(pentafluorobenzoate) using negative-ion chemical ionisation although selected-reaction chromatograms were cleaner than selected-ion chromatograms. The advantage of using GC-MS-MS was demonstrated by the detection of low levels of β-lyase metabolites in the urine of casualties who had been exposed to sulphur mustard.
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biological fate of sulphur mustard 1 1 thiobis 2 chloroethane identification of beta lyase metabolites and hydrolysis products in human urine
Xenobiotica, 1995Co-Authors: Robin M Black, Robert W ReadAbstract:1. Samples of urine from two human subjects accidentally exposed to sulphur mustard were analysed for metabolites derived from hydrolysis (Thiodiglycol, Thiodiglycol sulphoxide), conjugation with glutathione (1,1'-sulphonylbis [2-S-(N-acetylcysteinyl)ethane]) and from further metabolism of glutathione conjugates by the beta-lyase pathway (1,1-sulphonylbis[2-(methylsulphinyl)ethane], 1-methylsulphinyl-2-[2-(methylthio)ethylsulphonyl]ethane). 2. Thiodiglycol sulphoxide was excreted in much higher concentrations than Thiodiglycol, as was observed previously in rat exposed to sulphur mustard. However, the use of Thiodiglycol sulphoxide as a biological marker for sulphur mustard poisoning is limited by its presence at low concentrations in normal human urine. 3. beta-lyase metabolites were detected at concentrations comparable with those of Thiodiglycol sulphoxide. No background levels of beta-lyase metabolites have been detected in normal human urine, and they are proposed as unequivocal diagnostic and forensic indicators of sulphur mustard poisoning in man.
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application of gas chromatography mass spectrometry and gas chromatography tandem mass spectrometry to the analysis of chemical warfare samples found to contain residues of the nerve agent sarin sulphur mustard and their degradation products
Journal of Chromatography A, 1994Co-Authors: Robin M Black, Robert W Read, Raymond J Clarke, Michael T J ReidAbstract:Samples of clothing, grave debris, soil and munition fragments, collected from the Kurdish village of Birjinni, were analysed by GC-MS with selected ion monitoring (SIM) for traces of chemical warfare agents and their degradation products. Positive analyses were confirmed, where possible, by full scan mass spectra, or at low concentrations by additional GC-MS-SIM analysis using chemical ionisation, by higher resolution GC-MS-SIM, and by GC-tandem mass spectrometry using multiple reaction monitoring. Sulphur mustard and/or Thiodiglycol were detected in six soil samples; isopropyl methylphosphonic acid and methylphosphonic acid, the hydrolysis products of the nerve agent sarin, were detected in six different soil samples. Trace amounts of intact sarin were detected on a painted metal fragment associated with one of these soil samples. The results demonstrate the application of different GC-MS and GC-MS-MS techniques to the unequivocal identification of chemical warfare agent residues in the environment at concentrations ranging from low ppb to ppm (w/w). They also provide the first documented unequivocal identification of nerve agent residues in environmental samples collected after a chemical attack.
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application of headspace analysis solvent extraction thermal desorption and gas chromatography mass spectrometry to the analysis of chemical warfare samples containing sulphur mustard and related compounds
Journal of Chromatography A, 1993Co-Authors: Robin M Black, Robert W Read, Raymond J Clarke, David B Cooper, D UtleyAbstract:Abstract Samples of soil, munition fragments and wool, associated with a chemical warfare incident involving sulphur mustard, were analysed using headspace, solvent extraction and thermal desorption techniques combined with full scanning gas chromatography—mass spectrometry. Quantitative analysis was undertaken for sulphur mustard, mustard sulphoxide and Thiodiglycol, using solvent extraction and gas chromatography—mass spectrometry with selected ion monitoring. In a soil sample contaminated at ppm (w/w) levels all methods gave positive results for mustard and related compounds. Selected ion monitoring and thermal desorption were the more useful techniques at low ppb (w/w) levels. Cyclic decomposition products 1,4-thioxane and 1,4-dithiane appear to be useful indicators of mustard contamination when using thermal desorption analysis. The hydrolysis product Thiodiglycol and hydrolysis/elimination product 2-(vinylthio)ethanol appear to be useful indicators of mustard contamination in soil samples when employing extraction methods.
John L Provis - One of the best experts on this subject based on the ideXlab platform.
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portland cement based immobilization destruction of chemical weapon agent degradation products
Industrial & Engineering Chemistry Research, 2019Co-Authors: Sam A Walling, Stuart Notman, Pat Watts, Norman Govan, John L ProvisAbstract:The direct immobilization and destruction of two compounds relevant to chemical warfare agents, ethyl methylphosphonic acid (EMPA) and Thiodiglycol (TDG), within a freshly mixed Portland cement pas...
Paula Vanninen - One of the best experts on this subject based on the ideXlab platform.
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Determination of Mustard Gas Hydrolysis Products Thiodiglycol and Thiodiglycol Sulfoxide by Gas Chromatography-Tandem Mass Spectrometry after Trifluoroacetylation
Analytical Chemistry, 2014Co-Authors: Stanisław Popiel, Jakub Nawała, Daniel Dziedzic, Martin Söderström, Paula VanninenAbstract:A method for detecting mustard gas degradation products Thiodiglycol (TDG) and Thiodiglycol sulfoxide (TDGO) in water and sediment samples using gas chromatography-tandem mass spectrometry (GC-MS/MS) after derivatization with 1-(trifluoroacetyl)imidazole (TFAI) was described. Selected reaction monitoring mode (SRM) of tandem mass spectrometry was developed for analysis of TDG and TDGO derivatives while analysis by gas chromatography-atomic emission detector (GC-AED) was performed using the 181 nm sulfur canal. TFAI derivatization conditions were optimized and the method validated. Two derivatization agents were compared, TFAI and N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA), where derivatization using TFAI occurred quicker and under milder conditions than using BSTFA. Water samples containing TDG and TDGO were evaporated to dryness under nitrogen, dissolved in organic solvent followed by reaction with TFAI. The limit of detection (LOD) for TDG and TDGO were 0.01 and 5 ng/mL, respectively. The limit ...
Michael T J Reid - One of the best experts on this subject based on the ideXlab platform.
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application of gas chromatography mass spectrometry and gas chromatography tandem mass spectrometry to the analysis of chemical warfare samples found to contain residues of the nerve agent sarin sulphur mustard and their degradation products
Journal of Chromatography A, 1994Co-Authors: Robin M Black, Robert W Read, Raymond J Clarke, Michael T J ReidAbstract:Samples of clothing, grave debris, soil and munition fragments, collected from the Kurdish village of Birjinni, were analysed by GC-MS with selected ion monitoring (SIM) for traces of chemical warfare agents and their degradation products. Positive analyses were confirmed, where possible, by full scan mass spectra, or at low concentrations by additional GC-MS-SIM analysis using chemical ionisation, by higher resolution GC-MS-SIM, and by GC-tandem mass spectrometry using multiple reaction monitoring. Sulphur mustard and/or Thiodiglycol were detected in six soil samples; isopropyl methylphosphonic acid and methylphosphonic acid, the hydrolysis products of the nerve agent sarin, were detected in six different soil samples. Trace amounts of intact sarin were detected on a painted metal fragment associated with one of these soil samples. The results demonstrate the application of different GC-MS and GC-MS-MS techniques to the unequivocal identification of chemical warfare agent residues in the environment at concentrations ranging from low ppb to ppm (w/w). They also provide the first documented unequivocal identification of nerve agent residues in environmental samples collected after a chemical attack.