[Measurement of chlorodifluoromethane(HCFC-22) in the atmosphere by using an O2-induced electron capture detector (ECD)].
Chlorodifluoromethane (CHClF2, HCFC-22), a typical substitute of dichlorodifluoromethane(CF2Cl2, CFC-12), which atmospheric concentration was only at 10(-12) V/V level. After preconcentrated air sample, O2-Induced method was used to enhance sensitivity of ECD response to HCFC-22. When O2 concentration in carrier gas was 0.54%, there was the greatest value of S/N(signal to noise) and ECD response increased by about 500 times. With the study of other conditions, such as selection of the ECD temperature, programing of the column oven temperature and carrier gas flow, a practicable analysis method with high sensitivity of ECD was established.
Sun
H
H
Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China. haolins@hotmail.com
Chen
L
L
Yue
Z
Z
Sun
G
G
Ma
W
W
D000388:Air / Q000032:analysis*; D005617:Chlorofluorocarbons, Methane / Q000032:analysis*; D002849:Chromatography, Gas; D013696:Temperature
D005617:Chlorofluorocarbons, Methane; C009755:fluorocarbon 22