Mass spectrometry and stability of t-butyldimethylsilylethers of some estrogens and androstanes.

In addition to using radioimmunoassays for the determination of estrogens and other steroids, the possibility of using mass fragmentography for analysis was investigated. t-Butyldimethylsilyl chloride was selected as a reagent for derivatisation because it forms rather stable silylethers. In all the mass-spectra obrained from the steroid derivatives, one pronounced peak suitable for mass fragmentography was always present. Some of the spectra of the investigated estrogens, as well as testosterone, 3 alpha-hydroxy-5 alpha-androstan-17-one and 17 alpha-methyl-17 beta-hydroxy-5 alpha-androstan-3-one are discussed. The stability of various t-butyldimethylsilylethers and the rate of enolization of testosterone and progesterone in the presence of the silylation-agent under different conditions were established.