Abstract
The relative molar flame ionization detecton (FID) response (RMR)
for a hydrocarbon does not change when deuterium is substituted
for hydrogen. The exception is methane for which an inverse
deuterium effect of 3..5% is observed for tetradeuteriomethane.
[13C]Methane shows an inverse isotope effect of 2%. The reason for
the small or non-existent isotope effects is that H/2H exchange
takes place in the pre-combustion hydrogenolysis in the flame.
This was shown by taking samples from the lower part of the flame
by means of a fused silica capillary probe. By the same technique
the hydrogenolytic reactions in the hydrogen flame of compounds
added to the hydrogen gas in low concentrations were followed.
Alcohols, ethers, ketones, and esters all produced methane and
carbon monoxide, while amines produced methane and hydrogen
cyanide, halogen compounds methane and hydrogen halide, etc. The
FID response of an organic compound is the sum of the responses
from the products formed in the hydrogenolysis.
Original language | English |
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Journal | J. Chromatography |
Volume | A. 782 |
Pages (from-to) | 81-86 |
Publication status | Published - 1997 |