13C/12C of Volatile Organic Compounds (VOCS) In Airborne Samples by Thermal Desorption-Gas Chromatography-Isotope-Ratio-Mass Spectrometry (TD-GC-IRMS)

A preliminary investigation into the use of a thermal desorption-gas chromatography-isotope ratio mass spectrometry (TD-GC-ir-MS) method to determine stable carbon isotopic compositions (13C/12C) of low molecular-weight volatile organic compounds (VOCs) in airborne samples (e.g. industrial and car exhaust emissions) as a means of differentiating their sources in the environment has been carried out. Pure VOC standards (benzene, toluene, chlorobenzene, ethylbenzene, m-xylene and propylbenzene) were purchased from chemical distributors. A TD-GC-ir-MS method for obtaining 13C/12C of these VOCs in air samples has been optimised, and is proven to be both reproducible and linear. 13C/12C of the VOC standards were found to be comparable (within analytical error) to those obtained from direct GC-ir-MS analysis. This novel method of VOC analysis could be valuable in environmental and forensic investigations.

Personnel

N. Turner (Honours), K. Grice, M. Ioppolo Armanios, M. Jones, D. Dawson, S. Fisher

Funding

Centre of Excellence in Mass Spectrometry, Alcoa