Determination of terpene and related compounds in semi-urban air by GC-MSD

An automated gas chromatographic method using mass spectrometric detection for the determination of several biogenic hydrocarbons and some of their oxidation products in ambient tropospheric air is described. The method was used for the quantitation of ten monoterpenes, isoprene, methyl vinyl ketone and methacrolein. The method uses intermediate trapping steps on Tenax-TA sorbent, facilitating quantitative sampling of up to six liters of air without significant interference from water vapor or carbon dioxide. Practical limits of detection of 10 parts per trillion by volume for the target compounds were achieved. The use of the method in a extended measurement campaign, as part of the Southern Oxidant Study, near Atlanta, Georgia in the summer of 1992 is discussed.