Hi everyone,

I am working on the measurement of dissolved gases using membrane inlet
coupled with quadrupole mass spectrometer. When I pumped the air-saturated
water, the intensity of m/z 16 and 18 were similar but higher than that of
m/z 32 about an order of magnitude. The m/z 2 intensity also increased at
the same time. When I introduced tiny amount of air into the system, the
m/z 16, 18 and 2 all increased about a factor of 2. Supposed air should
have almost no hydrogen and methane (or others with m/z 16), the intensity
of m/z 2 and 16 should not increase. Is it possible that the m/z 18
dissociate to m/z 16 and 2 and some m/z 16 combines each other to form m/z
32? Can anyone help me to explain this?

BTW, does anyone know Nafion water trap?

Thanks a lot.


Li-Hung Lin
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Li-Hung Lin
Department of Geosciences, Princeton University