Measuring Hydrocarbons in the Atmosphere

Hydrocarbons play a significant role in the chemistry of the troposphere. They are not only emitted into the atmosphere from a wide variety of natural and anthropogenic sources but they may also be formed via atmospheric transformations. This chapter focuses on volatile organic compounds (VOCs). The collection and measurement of VOCs has been the subject of countless studies. Measurements of VOCs in the atmosphere have generally been made with gas chromatographic analyses of air samples collected in canisters, on adsorbents or in cryostats. The sample-collection step plays a crucial role in the analytical process, as it determines the representativeness of the sample. Canisters are most useful for very volatile, nonpolar compounds while sorbent tubes are more applicable for less volatile analytes. Their wide use in air monitoring has resulted in the development of a number of protocols for the analysis of a broad range of VOCs.