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[A-7.1.4 Behaviors of CFC Alternatives in the Atmosphere]

[Contact Person]

Takeshi Tominaga
Faculty of Science, The University of Tokyo
Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan
Tel:+81-3-3812-2111(ext.4346)
Fax:+81-3-5800-6890

[Total Budget for FY1991-1992]

9,593,000 Yen

[Abstract]

　Production and use of ozone-destroying CFCs have been controlled with a goal of the complete phaseout and several alternative compounds (HCFCs and HFCs) have been proposed. Analytical systems and procedures were developed to achieve highly sensitive and precise determination of CFC alternatives in the atmosphere. Background air samples collected in Hokkaido were analyzed to obtain their atmospheric concentrations. The following results were obtained in this work:
　1. Since HCFC-22(CHCIF₂) and HFC 134a(CH₂FCF₃) (typical CFC alternatives) are hardly detectable in ECD gas chromatography we attempted to enhance the HCFC-22 sensitivity in ECD by adding oxygen into the carrier gas, and preconcentration of the components in the air samples at low temperatures was also examined. Trend in average atmospheric concentration of HCFC-22 was roughly estimated in these preliminary measurements.
　2. While GC/FID and GC/MS methods were examined for the detection of HFC-134a, neither method was sensitive enough to detect the extremely low concentration level of HFC-134a currently anticipated.

[Key Words]

CFC Alternatives, HCFC-22, HFC-134a, Atmospheric Concentration, Ultratrace Analysis