Measurement of plasma prostaglandin F2 alpha using capillary gas chromatography negative ion chemical ionization mass spectrometry

A stable isotope dilution gas chromatography/mass spectrometry method for the measurement of prostaglandin F2 alpha (PGF2 alpha) in plasma has been developed. The linearity of the method was 0 to 250 pg per ml, day-to-day precision of five percent at a level of 80 pg per ml, and a limit of detection of one pg per ml. Evaluation of the absolute recovery of PGF2 alpha through the sample clean-up steps using tritium labelled PGF2 alpha gave recoveries of 68 +/- 5 percent. A preliminary reference range estimated a mean plasma PGF2 alpha level of 83 +/- 13 pg per ml (n = 7) with a range of 62 to 103 pg per ml in healthy adults. The major application of this method will be in research protocols studying changes of PGF2 alpha in toxemia of pregnancy.