The F and 19-hydroxy F prostaglandins and their 8 beta-isomers in human seminal plasma: data on chromatography and mass spectrometry.

Human seminal plasma contains eight different prostaglandins belonging to the F series, i.e. PGF1 alpha, PGF2 alpha, 19-hydroxy-PGF1 alpha, 19-hydroxy PGF2 alpha, as well as the corresponding 8 beta-isomers. A systematic description of the mass spectrometric fragmentation of the 8 beta-isomers has not been previously reported. In the present study the prostaglandins were separated from human seminal plasma and analysed as methylester, trimethylsilylethers with gas chromatography mass spectrometry. All the eight F and 19-hydroxy F prostaglandins fragmented in the same manner, but the relative abundances of the formed ions varied in a typical way. Thus, the mass spectra of 8 beta-PGF1 alpha and 8 beta-19-hydroxy PGF1 alpha differed clearly from those of their 8 alpha-isomers, which could be used for identification and should be considered in selected ion monitoring. The ratio between the seminal plasma levels of 8 beta- and 8 alpha-isomers of 19-hydroxy F1 alpha was much higher than the corresponding ratio for the PGF1 alpha.