A gas chromatographic system was used to quantitate more than 300 gas-phase hydrocarbons from background and roadside ambient air samples. Samples were simultaneously collected in Tedlar bags and on Tenax cartridges. Hydrocarbons from Tedlar bag-collected samples were quantitated on a gas chromatograph arranged in a dual column configuration and equipped with a flame ionization detector. The C2 and C3 hydrocarbons were separated on a 5-m long stainless steel column packed with silica gel; C4 to C13 hydrocarbons were separated on a 125-m long glass capillary column containing 7.5% hydrophobic silica. A stainless steel hydrocarbon trap filled with untreated glass wool permitted the concentration of at least 4-L of sample at 70% relative humidity. This extends the detection limits for individual hydrocarbons to 15.0 parts per trillion carbon. A programmable valve controller maintained trap cooling during hydrocarbon concentration and thermally desorbed the hydrocarbons for gas chromatographic analysis.

Publication date from NTRL. Fifteen leaves of text followed by tables and charts. Includes bibliographical references.