A comparison of t ‐butyldimethylsilyl and trimethylsilyl ether derivatives for the characterization of urinary metabolites of prostaglandin F 2α by gas chromatography mass spectrometry

t ‐Butyldimethylsilyl and trimethylsilyl ether derivatives of a series of methylated prostaglandin F 2α metabolites have been compared with respect to their gas chromatographic and mass spectrometric properties. The t ‐butyldimethylsilyl derivatives had considerably higher retention indices (approximately 2.2 C units per silyl group) than their trimethylsilyl ether counterparts when analysed on the (non‐polar) OV‐1 stationary phase. Electron impact induced fragmentation patterns were strongly dependent upon the type of silyl ether employed and on the nature of the prostaglandin ω sidechain; the mass spectra of pairs of t ‐butyldimethylsilyl and trimethylsilyl ether derivatives were found to differ appreciably in several respects and to afford complementary structural information.