| Title: | deltaD and delta13C analyses of atmospheric volatile organic compounds by thermal desorption gas chromatography isotope ratio mass spectrometry |
| Author(s): | von Eckstaedt CV; Grice K; Ioppolo-Armanios M; Chidlow G; Jones M; |
| Address: | "WA-Organic and Isotope Geochemistry Centre, The Institute for Geoscience Research, Department of Chemistry, Curtin University, Building 500, Kent Street, GPO Box U1987, Perth, WA 6845, Australia. C.v.Eckstaedt@gmx.de" |
| DOI: | 10.1016/j.chroma.2011.06.098 |
| ISSN/ISBN: | 1873-3778 (Electronic) 0021-9673 (Linking) |
| Abstract: | "This paper describes the establishment of a robust method to determine compound specific deltaD and delta(13)C values of volatile organic compounds (VOCs) in a standard mixture ranging between C(6) and C(10) and was applied to various complex emission samples, e.g. from biomass combustion and car exhaust. A thermal desorption (TD) unit was linked to a gas chromatography isotope ratio mass spectrometer (GC-irMS) to enable compound specific isotope analysis (CSIA) of gaseous samples. TenaxTA was used as an adsorbent material in stainless steel TD tubes. We determined instrument settings to achieve a minimal water background level for reliable deltaD analysis and investigated the impact of storage time on deltaD and delta(13)C values of collected VOCs (176 days and 40 days of storage, respectively). Most of the standard compounds investigated showed standard deviations (SD)<6 per thousand (deltaD) when stored for 148 days at 4 degrees C. However, benzene revealed occasionally D depleted values (21 per thousand SD) for unknown reasons. delta(13)C analysis demonstrated that storage of 40 days had no effect on VOCs investigated. We also showed that breakthrough (benzene and toluene, 37% and 7%, respectively) had only a negligible effect (0.7 per thousand and 0.4 per thousand, respectively) on delta(13)C values of VOCs on the sample tube. We established that the sample portion collected at the split flow effluent of the TD unit can be used as a replicate sample for isotope analysis saving valuable sampling time and resources. We also applied TD-GC-irMS to different emission samples (biomass combustion, petrol and diesel car engines exhaust) and for the first time deltaD values of atmospheric VOCs in the above range are reported. Significant differences in deltaD of up to 130 per thousand were observed between VOCs in emissions from petrol car engine exhaust and biomass combustion (Karri tree). However, diesel car emissions showed a high content of highly complex unresolved mixtures thus a baseline separation of VOCs was not achieved for stable hydrogen isotope analysis. The ability to analyse deltaD by TD-GC-irMS complements the characterisation of atmospheric VOCs and is maybe used for establishing further source(s)" |
| Keywords: | Atmosphere/chemistry Biomass Carbon Isotopes/*analysis Deuterium/*analysis Gas Chromatography-Mass Spectrometry/*methods Reproducibility of Results Vehicle Emissions/analysis Volatile Organic Compounds/*analysis Water; |
| Notes: | "Medlinevon Eckstaedt, Christiane Vitzthum Grice, Kliti Ioppolo-Armanios, Marisa Chidlow, Geoff Jones, Mark eng Research Support, Non-U.S. Gov't Netherlands 2011/08/03 J Chromatogr A. 2011 Sep 16; 1218(37):6511-7. doi: 10.1016/j.chroma.2011.06.098. Epub 2011 Jul 3" |
