Negative ion chemical ionization gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry of prostanoid pentafluorobenzyl ester/methoxime/trimethylsilyl ether derivatives.

Negative ion chemical ionization mass spectra of prostaglandin F2 alpha, prostaglandin E2, prostaglandin D2, 6-oxo-prostaglandin F1 alpha, 2,3-dinor-6-oxo-prostaglandin F1 alpha, thromboxane B2, 2,3-dinor-thromboxane B2, and 11-dehydro-thromboxane B2 pentafluorobenzyl ester (PFB)/methoxime/trimethylsilyl ether derivatives are presented. Collisionally activated decomposition mass spectra of the [M-PFB]- ions at collision energies of 8-24 eV and argon collision gas pressures of 1-2m Torr almost show only fragmentation of trimethylsilanol, (CH3)2Si = CHOH, (CH3)2Si = CH2 and methanol whereas, except for carbon dioxide loss, only few low-intensity fragments from the carbon skeleton of the prostanoids are observed.