CHClF₂ (F‐22) in the Earth's atmosphere

Recent global measurements of CHClF 2 (F‐22) are reported. Originally, GC/MS techniques were used to obtain these data. Since then, significant advances using an O 2 ‐doped electron capture detector have been made in the analytical techniques, so that F‐22 can be measured by EC/GC methods at ambient concentrations. The atmospheric burden of F‐22 calculated from these measurements (average mixing ratio, mid‐1979, ∼45 pptv) is considerably greater than that expected from the estimates of direct industrial emissions (average mixing ratio, mid‐1979, ∼30 pptv). This difference is probably due to underestimates of F‐22 emissions.