Elimination of DzO from deuterated 4 affords the abundant ion at m/e 270. As expected only one molecule of DzO is lost since the second hydroxyl group is attached to the aromatic ring. In contrast, the cardenolide, digitoxigenin (5), affords a CI(D20) spectrum containing peaks corresponding to the successive loss of DzO and HDO from the d2-5 D+ion.
+
OH
. I
4
5
In addition to the above examples, we have also obtained CI (D20) spectra on a number of compounds containing one or more common organic functional groups. Our findings
indicate that hydrogen bonded to heteroatoms in alcohols, phenols, carboxylic acids, amines, amides, and mercaptans undergoes essentially complete exchange in the ion source when DzO is employed as the reagent gas at a pressure of 0.4 Torr. Small amounts of deuterium incorporation (
