@article {401,
	title = {Contributions of toluene and alpha-pinene to SOA formed in an irradiated toluene/alpha-pinene/NOx/air mixture: Comparison of results using C-14 content and SOA organic tracer methods},
	journal = {Environmental Science \& Technology},
	volume = {41},
	year = {2007},
	note = {id: 1882; 172ZM Times Cited:13 Cited References Count:19Y},
	pages = {3972-3976},
	abstract = {An organic tracer method, recently proposed for estimating individual contributions of toluene and alpha-pinene to secondary organic aerosol (SOA) formation, was evaluated by conducting a laboratory study where a binary hydrocarbon mixture, containing the anthropogenic aromatic hydrocarbon, toluene, and the biogenic monoterpene, alpha-pinene, was irradiated in air in the presence of NOx to form SOA. The contributions of toluene and alpha-pinene to the total SOA concentration, calculated using the organic tracer method, were compared with those obtained with a more direct C-14 content method. In the study, SOA to SOC ratios of 2.07 +/- 0.08 and 1.41 +/- 0.04 were measured for toluene and alpha-pinene SOA, respectively. The individual tracer-based SOA contributions of 156 mu g m(-3) for toluene and 198 mu g m(-3) for alpha-pinene, which together accounted for 82\% of the gravimetrically determined total SOA concentration, compared well with the C-14 values of 182 and 230 mu g m(-3) measured for the respective SOA precursors. While there are uncertainties associated with the organic tracer method, largely due to the chemical complexity of SOA forming chemical mechanisms, the results of this study suggest the organic tracer method may serve as a useful tool for determining whether a precursor hydrocarbon is a major SOA contributor.},
	issn = {0013-936X},
	doi = {10.1021/Es070089+},
	author = {Offenberg, J. H. and Lewis, C. W. and Lewandowski, M. and Jaoui, M. and Kleindienst, T. E. and Edney, E. O.}
}
@article {1939,
	title = {Absence of 14C in PM2.5 Emissions from Gasohol Combustion in Small Engines},
	journal = {Aerosol Science and Technology},
	year = {2006},
	note = {id: 1699},
	month = {2006},
	author = {Lewis, C. W. and Volkens, J. and Braddock, J. N. and Crews, W. S. and Lonneman, W. A. and McNichol, A. P.}
}
@article {795,
	title = {Radiocarbon measurements of atmospheric volatile organic compounds: Quantifying the biogenic contribution},
	journal = {Environmental Science \& Technology},
	volume = {30},
	year = {1996},
	note = {Uc413Times Cited:26Cited References Count:25},
	month = {Apr},
	pages = {1098-1105},
	abstract = {The radiocarbon (C-14) abundance of atmospheric volatile organic compounds (VOC) gives a quantitative estimate of contributions from biomass and fossil-mass sources, important information for effective regulation of ozone precursors. We report here details of a methodology to perform such measurements and the first exploratory C-14 results on VOC fractions separated from two composited urban tropospheric air samples, collected during the summer (1992) in Atlanta, GA. The upper limit of the percentage of VOC originating from biomass sources during the morning and evening hours in Atlanta were 9 and 17\%, respectively, measurements reported at the 95\% confidence level. However, due to the level of the process blank and its uncertainty, in both cases the percentage can be as low as zero. The results of these experiments, designed to (i) evaluate the entire [C-14]VOC measurement process and (ii) obtain reliable estimates of biogenic contributions to atmospheric VOC, emphasize how important controls are throughout this multi-step chemical process to ensure quality data.},
	issn = {0013-936x},
	doi = {10.1021/es9501981},
	author = {Klouda, G. A. and Lewis, C. W. and Rasmussen, R. A. and Rhoderick, G. C. and Sams, R. L. and Stevens, R. K. and Currie, L. A. and Donahue, D. J. and Jull, A. J. T. and Seila, R. L.}
}
