The helium charge exchange and the isobutane chemical ionization spectra of 4-methoxy cyclohexanecarboxylic acid ethyl esters (1c and 1t), 2,6-dimethyl-4-hydroxytetrahydropyranes (2c and 2t), 2,4,6-trimethyl-4-hydroxytetrahydropyranes (8c and 3t), and 2,7-dimethoxy-cis-decalins (4c and 4t) have been screened for correlations with the stereochemistry of these molecules. From these data it appears that chemical ionization is especially suited for configurational assignments in epimeric molecules.
Ammonia chemical ionization mass spectrometry of intact diacyl phosphatidylcholine