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12 results on '"Sheng, G.Y."'

2. Development of a compound-specific carbon isotope analysis method for atmospheric formaldehyde via NaHS[O.sub.3] and cysteamine derivatization

Author

Yu, Y.X., Wen, S., Feng, Y.L., Bi, X.H., Wang, X.M., Peng, P.A., Sheng, G.Y., and Fu, J.M.

Subjects
Cysteamine -- Structure, Cysteamine -- Research, Gas chromatography -- Analysis, Mass spectrometry -- Analysis, Carbon -- Isotopes, Carbon -- Structure, Carbon -- Properties, Carbon -- Electric properties, Chemistry
Abstract

A novel method has been developed for the compound-specific carbon isotope analysis of atmospheric formal-dehyde using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The method allows the determination of the [[sigma].sup.13]C value for atmospheric formaldehyde at nanogram levels with higher precision and lower detection limit. In the present work, atmospheric formaldehyde was collected using NaHS[O.sub.3]-coated Sep-Pak silica gel cartridges, washed out by water, then derivatized by cysteamine of known [[sigma].sup.13]C value, and the [[sigma].sup.13]C value of its derivative (thiazolidine) determined by GC/C/IRMS. Finally, the [[sigma].sup.13]C value of atmospheric formaldehyde could be calculated by a simple mass balance equation between formaldehyde, cysteamine, and thiazolidine. Using three formaldehydes with different [[sigma].sup.13]C values, calibration experiments were carried out over large ranges of formaldehyde concentrations. The carbon isotope analysis method achieved excellent reproducibility and high accuracy. There was no carbon isotopic fractionation throughout the derivatization processes. The differences in the carbon isotopic compositions of thiazolidine between the measured and predicted values were always

Published
2006

8. Polar organic tracers in <tex>PM_{2.5}$</tex> aerosols from forests in eastern China

Author

Wang, Wu, Wu, M.H., Zhang, T., Liu, X.D., Feng, J.L., Li, H.J., Wang, Y.J., Sheng, G.Y., Claeys, Magda, and Fu, J.M.

Subjects
Chemistry, Pharmacology. Therapy
Abstract

Photooxidation products of biogenic volatile organic compounds, mainly isoprene and monoterpenes, are significant sources of atmospheric particulate matter in forested regions. The objectives of this study were to examine time series and diel variations of polar organic tracers for the photooxidation of isoprene and á-pinene to investigate whether they are linked with meteorological parameters or trace gases, and to determine their carbon contributions. In addition, the biogenic secondary organic carbon contributions from isoprene were estimated. PM2.5 (particulate matter with an aerodynamic diameter

Published
2008

11. Organic geochemistry of palaeokarst-hosted uranium deposits, south China.

Author

Min M.Z., Liu X., Meng Z.W., Min Y.S., Sheng G.Y., Min M.Z., Liu X., Meng Z.W., Min Y.S., and Sheng G.Y.

Abstract

The Saqisan, Sanqilinyi and Sanbaqi deposits are hosted by Devonian to Carboniferous carbonate rocks rich in organic matter and clays. The organic matter is chiefly of marine origin and in unmineralised samples is immature, indicating a history of generally low temperatures and shallow maximum burial. The deposits formed as a result of repeated karstification during the Hercynian and Yanshanian regional tectonic periods, accumulation of organic matter and clays in the caverns and breccias, fixation and adsorption of uranium leached from the host carbonates, reduction by organic matter, and reworking of the protores to form uraninite and coffinite., The Saqisan, Sanqilinyi and Sanbaqi deposits are hosted by Devonian to Carboniferous carbonate rocks rich in organic matter and clays. The organic matter is chiefly of marine origin and in unmineralised samples is immature, indicating a history of generally low temperatures and shallow maximum burial. The deposits formed as a result of repeated karstification during the Hercynian and Yanshanian regional tectonic periods, accumulation of organic matter and clays in the caverns and breccias, fixation and adsorption of uranium leached from the host carbonates, reduction by organic matter, and reworking of the protores to form uraninite and coffinite.

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