HYDROXYL ION NEGATIVE CHEMICAL IONIZATION MASS-SPECTRA OF STEROIDS

The OH- negative chemical ionization spectra of 35 steroids have been investigated. Spectra are dependent upon the nature, number, proximity of the functional groups in the several compounds. The predominant reaction observed is proton abstraction, (M-1)- is found for all but two compounds. Other reactions involve nucleophilic attack by OH- on the sample molecule and nucleophilic attack by (M-1)- on N2O. These processes are frequently accompanied by loss of H2 and H2O, which sometimes aids in determining the nature and environment of substituents in the compounds. The amount of the fragmentation of the molecules is relatively small. The overall sensitivity of the method is somewhat greater than that for CH4 positive chemical ionization with the group of steroids investigated. © 1979, American Chemical Society. All rights reserved.