A comparative,vapor-phase (G.L.C.-M.S.) study of various derivatives of prostaglandins A and B

The isomeric prostaglandins, A and B, can be readily distinguished by differences in the mass spectra of their derivatives. The mass spectra of the PGA₁- or PGA₂-methyl ester (ME)-trimethyl silyl (TMS) ether derivatives have a prominent ion at M ? 71]⁺ or M ? C₅H₁₁]⁺ while those of the PGB₁- or PGB₂-ME-TMS derivatives have a predominant ion at M ? 99]⁺ or M ? C₆H₁₁O]⁺ in addition to that at M ? 71]⁺. Ions of similar origin characterize the spectra of the PGA₁- or PGA₂-TMS ether-TMS ester and PGB₁- or PGB₁-TMS-TMS derivatives, respectively. The fragmentation of other derivatives of PGA₁, PGA₂, PGB₁ and PGB₂ such as the ME-t-Bu-DMS (t-butyl-dimethylsilyl ether); ME-MO (methoxime)-TMS; ME-MO-Ac (acetate), and ME-Ac are also described comparatively. The composition of important ions was confirmed by deuterium labeling and/or high resolution mass spectroscopy, where appropriate. The potential advantages and limitations of the derivatives for quantitative analysis of prostaglandins by the specialized technique of multiple ion detection (MID) are described.