Differences in the low-energy collision-activated dissociation of carboxylate anions from structurally similar prostaglandins: E2, F 2α, D 2, and DHKF 2α.

Some intriguing discoveries were made concerning the collision-activated dissociation behavior of the derivatized carboxylate anions of PGE2 and PGF2α. The carboxylate anion [MPFB](-) formed from electron-capture negative chemical ionization of the pentafluorobenzyl ester-trimethylsilyl derivative of PGF2α showed little fragmentation under typical collision gas pressures and energies (<2.0 mtorr N2 and <20 eV). In contrast, the daughter spectra of the carboxylate anion of the methoxime-pentafluorobenzyl ester-trimethylsilyl derivative of PGE2 produced many intense fragments under the same conditions.