DETERMINATION OF 1,2-DICHLOROTETRAFLUOROETHANE (CFC-114) CONCENTRATION IN THE ATMOSPHERE

Atmospheric concentration of 1,2-dichlorotetrafluoroethane (CFC-114) w as determined accurately by the complete separation of its isomer 1,1- dichlorotetrafluoroethane (CFC-114a). The trends of atmospheric CFC-11 4 concentrations since 1986 were observed in Hokkaido, Japan (40-45 de grees N), and Syowa Station, Antarctica (69 degrees S). The atmospheri c CFC-114 concentration in the mid-latitude Northern Hemisphere increa sed by 0.75 pptv / year over the period 1986-1990, and 0.6 pptv / year over 1990-1993. Vertical distribution of CFC-114 was also obtained up to mid-stratosphere.