Studies in chemical ionization mass spectrometry: 17‐hydroxy steroids

The chemical ionization mass spectra of several hydroxy steroids were obtained using methane as the reactant gas. The spectra are much less complex than the electron ionization spectra and little fragmentation of the steroid nucleus is observed. The major fragment ions involve the loss of water from [M + H] + . A 3‐keto group in the steroids was characterized by an abundant [M + C 2 H 5 ] + ion. 5α‐ and 5β‐Dihydrotestosterone could be distinguished by their spectra, with H 2 as the reactant gas by marked differences in amounts of [M + H] + , [M + H − H 2 O] + and [M + H − 2H 2 O] + . Substituted 3α‐X‐, 17 β‐ol compounds, (X = Cl, Br) were also studied to obtain relative amounts of protonation at these sites.