Isotopic (14C) and Chemical Composition of Atmospheric Volatile Organic Compounds-Precursors to Ozone
George A. Klouda, C. W. Lewis, R A. Rasmussen, D C. Stiles, W D. Ellenson, J L. Marolf, R. K. Stevens
Atmospheric volatile organic compounds (VOCs) are an important factor in the production of ozone near ground level . Many hydrocarbons origanate from auto exhaust. However, a number of VOCs e.g., isoprene, are known to be natural in origin. To develop reliable modelsfor understanding how ozone levels might be controlled, it has been recognized that a key variable is the fractional amount of fossil vs. non-fossil (biogenic, uncontrollable) VOCs . These two source categories are uniquely discriminated from each other based on the 14C abundance of VOC fractions. Combining isotopic measurements with chemical information will yield greater confidence in source estimates. Over the last 8 years, NIST, OGI and the U.S. EPA have explored sampling methods and analytical procedures to collect enough carbon from atmospheric non-methane VOC fractions to measure the 14C composition [4,9]. In doing so, this work also provided an opportunity to enhance the sensitivity of GC-FID and GC-MS for chemical identification and quantification. This paper will briefly describe the methods studied and present preliminary 14C and chemical results from Azusa, CA, Houston, TX, and Nashville, TN, USA.
Proceedings of the Third International Conference on Isotopes: Isotope Production and Applications in the 21st Century
, Lewis, C.
, Rasmussen, R.
, Stiles, D.
, Ellenson, W.
, Marolf, J.
and Stevens, R.
Isotopic (<sup>14</sup>C) and Chemical Composition of Atmospheric Volatile Organic Compounds-Precursors to Ozone, Proceedings of the Third International Conference on Isotopes: Isotope Production and Applications in the 21st Century , Vancouver,
(Accessed December 8, 2023)