MEASUREMENT OF C-2 C-6 NONMETHANE HYDROCARBONS IN THE BACKGROUND ATMOSPHERE OF TAIWAN BY USING THE CANISTER GAS-CHROMATOGRAPHY METHOD

The system for analyzing C2 - C6 nonmethane hydrocarbons (NMHC's) usin g the gas chromatographic technique with an Al2O3/KCl PLOT column comb ined with a canister sampling device was successfully used to measure background air samples. The NMHC compounds stored in a humidified cani ster were stable. Any contaminated canister was easily cleaned under h igh-vacuum condition. A total of 52 compounds of C2 - C6 NMHC's were f ound; 34 of these were identified, and were consistent with results fr om laboratories around the world. One should be careful concerning elu ent peak identification of the isobutane-acetylene and propyne-1-penta ne pairs. An absolute quantification of 1-butane was checked within an 8% deviation by participating in an international hydrocarbon experim ent. The detection limits were typically in the 10 part-per-trillion ( v/v) range. The reproducibility was 5 - 7% precision at the 1 - 10 ppb level. The system described here is capable of urban, remote and back ground air studies. Samples were collected at a remote ocean island of Lanyu, Taiwan, during the period from Sep. 20 to Oct. 18, 1999.