Determination of Deuterated Methanes for Use as Atmospheric Tracers

摘要

The deuterated methanes, sup 13 CD sub 4 and sup 12 CD sub 4 , are useful as tracers for long-range (>500-km) atmospheric transport. They are easily synthesized and released. Sampling is accomplished by collecting about 330 l of air and chromatographically separating the methane fraction, which is then analyzed by mass spectrometry for the sup 13 CD sub 4 / sup 12 CH sub 4 and sup 12 CD sub 4 / sup 12 CH sub 4 ratios. Detection limits in air are about 7 x 10 sup -16 STP mol m sup -3 for sup 13 CD sub 4 and 2 x 10 sup -15 STP mol m sup -3 for sup 12 CD sub 4 . 11 refs., 5 figs.