Analysis of picomolar concentrations of 6-oxo-prostaglandin F 1 in biological fluids

Abstract

A highly sensitive and specific assay for the quantitation of 6-oxo-prostaglandin F 1, the stable hydrolysis product of prostacyclin, is described. The method involves the addition of [3,3′,4,4′- 2H 4]-6-oxo-prostaglandin F 1 as internal standard, extraction from biological fluids using μBondapak C 18 reversed-phase Sep-Paks, and preliminary purification by normal-phase chromatography. Following conversion to the methoxime, tris-trimethylsilyl, pentafluorobenzyl derivative, samples were analysed using combined capillary column gas chromatography negative ion chemical ionisation mass spectrometry. Fragment ions at m/z 614 ( 1H) and 618 ( 2H) [M  C 7H 2F 5] − were monitored for quantitation. This method was used for the measurement of endogenous levels of 6-oxo-prostaglandin F 1 in human urine and for the determination of prostacyclin release from rat peritoneal mast cells and from rat aortic rings incubated in human plasma.