Premium
Allyldimethylsilyl ethers as derivatives for the characterization of steroids and cannabinoids by combined gas chromatography and mass spectrometry
Author(s) -
Harvey D. J.
Publication year - 1977
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200040414
Subject(s) - chemistry , trimethylsilyl , polyatomic ion , mass spectrum , mass spectrometry , ion , silylation , fragmentation (computing) , substituent , bstfa , gas chromatography , fast atom bombardment , gas chromatography–mass spectrometry , chromatography , medicinal chemistry , organic chemistry , catalysis , computer science , operating system
The allyldimethylsilyl ethers of thirteen mono‐ and dihydroxy steroids and eleven cannabinoids were examined by combined gas chromatography mass spectrometry and their properties compared with those of the corresponding trimethylsilyl and t ‐butyldimethylsilyl ethers. The spectra of the allyldimethylsilyl derivatives of the steroids exhibited abundant ions produced by elimination of the larger (allyl) silyl substituent and were thus found to be useful for single ion monitoring studies. Ion currents carried by the [M‐allyl] + ions were slightly less than those carried by the [M‐ t ‐butyl] + ions from the t ‐butyldimethylsilyl derivatives, but the spectra exhibited more abundant molecular ions and ions characteristic of the presence of specific functional groups such as a Δ 5 ‐3β‐hydroxy structure. In addition they produced a lower molecular weight increase than the t ‐butyldimethylsilyl derivatives and had shorter retention times. The mass spectral fragmentations shown by the corresponding derivatives of the cannabinoids were very similar to those of the trimethylsilyl derivatives with the addition of abundant ions resulting from loss of the allyl or t ‐butylsilyl radical. However, these ions did not carry such high ion currents as the corresponding ions in the steroid spectra and were thus of limited use for single ion studies. The allyldimethylsilyl derivatives of the cannabinoid metabolites produced more abundant molecular ions than either the trimethylsilyl or t ‐butyldimethylsilyl derivatives. Fragmentation pathways involving elimination of C 3 H 6 were found to be specific for the allyldimethylsilyl derivatives.