Hydrogen-deuterium exchange in fused-silica capillary columns.

Ketones deuteriated alpha to the carbonyl have been observed to undergo significant isotope exchange on fused-silica capillary columns during gas chromatography-mass spectrometry. The residence time of the compounds on the column was found to influence the extent of isotope exchange. The degree of exchange was examined using a variety of columns and the isotope exchange was found to occur even with brand new columns. Conversion of the keto compounds into the methyloxime derivatives resulted in retention of the "correct" isotope content during gas chromatography-mass spectrometry.