Abstract: Analysis and Research of Trace Organic Gases in Atmosphere by GC/MSWang Yuesi;Wang Mingxing;Liu Guangren(Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100083,China)Shi Junhui(National Research Centre for Environmental Analysis and Measurements.Beijing 100012,China)Received Abstract:An automated Air Sample Concentrator/Gas Chromatograph/Mass Spectrometer(ASC/GC/MS)is described for the urban and field atmosphere monitoring of trace organic gases,included hydrocarbons(HCs),hydrofluorocarbons(HFCs) and hydrochlorofluorocarbons(HCFCs).Detection limits 20pptv are achieved by concentration of 500~100 cm3 air sample onto a two-stage cryotrap.The enriched air sample is thermally desorbed by direct ohmic heating of the glasss beadfilled microtrap and quickly transported to the head of GC colmn cryofocussing there.The cooled column head is heated in a high speed of 50℃/s and the air sample is"injected" to the column.Individual organic compounds are determined by selected ion masses for quantitation.The all system is designed to operate automatically at an atmospheric monitor or research centres providing about 1.5 hour kreplicate calibration analyses.Keywords:atmosphere,organic compound,analysis,research