Sensitive method for the determination of 6-oxo-prostaglandin F1 alpha by gas chromatography with electron-capture and mass-fragmentographic detection.

A selective and sensitive quantitative method is described for the determination of the endogenous prostacyclin content of the aorta of rats, treated with GYKI-11679, a new hydrazone derivative with antihypertensive action. The thoracal aorta from three rats was excised and pooled, 1 h after treatment with 10 mg/kg of GY-KI-11679. The prostacyclin, transformed to 6-oxo-PGF1 alpha, was extracted. For gas chromatographic electron-capture detection (GC-ECD), 6-oxo-PGF1 alpha was converted into the O-methyloxime tris(trifluoroacetyl) hexafluoroisopropyl ester derivative. The GC-ECD properties, stability and mass-spectrometric characteristics of this new derivative allow the quantitative analysis of 6-oxo-PGF1 alpha by using nor-PGF2 alpha as internal standard.