Description of the analysis of a wide range of volatile organic compounds in whole air samples collected during PEM-Tropics A and B

A large number of hydrocarbons, halocarbons, and organic nitrates were quan tified in whole air samples acquired for the NASA-sponsored GTE missions PE M-Tropics A and B. The samples were collected in electropolished stainless steel canisters from two aircraft while flying over the Pacific Basin. Two nominally identical multicolumn multidetector gas chromatographic analytica l systems were employed. Whole air samples were also used as working and ca librated standards and were collected specifically for this purpose. This p aper describes the analytical procedure employed during PEM-Tropics B. Mino r differences in the PEM-Tropics A system will also be discussed. More than 3900 samples were analyzed for 34 gases during PEM-Tropics A, over 4500 sa mples were analyzed for 58 gases during PEM-Tropics B. An overview is prese nted of the collection, analysis, and quantification of whole air samples d uring the PEM-Tropics missions, along with an analysis of the analytical pr ecision achieved during these missions.