title: [Measurement method research on trace volatile organic compounds in atmosphere].
abstract: An automated accumulation sampling system and a method of two-step Cryo-Concentrated System combined with Gas Chromatography/Mass Spectrometry (CCS-GC/MS) are introduced. The method is evaluated by a set of special experiments and the results are demonstrated. The lowest limit volume concentrations of the measurement is expanded from 10 (-6) to 10(-12) using CCS-GC/ MS instead of the normal method of GC/MS and the average response factor of 39 object compounds is 2.9 x 10(-12) x A(-1). When injection volume of air sample reaches 1000 cm3, the lowest limit is 7 x 10(-12) - 40 x 10(-12); CCS-GC/MS may identify all the objective chemical species in the atmosphere samples, with average 2.5s bias of retention time for 39 GC peaks. Within 0 - 400 x 10(-9), the concentration of all the objective compounds can be calculated by standard curve individually (average r2 above 0.99) and accurately. The recollect rate is 88% - 111%, at average of 100.8% +/- 5.6%; and the bias of precision is 2% - 14%, at average of 6.6%.
authors.affiliation: Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. wys@dq.cern.ac.cn
authors.forename: Yue-Si
authors.initials: YS
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Tian-Yang
authors.initials: TY
authors.lastname: Xiu
authors.forename: Ying-Hong
authors.initials: YH
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D009930:Organic Chemicals / Q000032:analysis*; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D009930:Organic Chemicals