Simultaneous determination of prostanoids in plasma by gas chromatography-negative-ion chemical-ionization mass spectrometry.
A method for simultaneous determination of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), and thromboxane B2 (TxB2) in plasma was developed. After acidification and addition of 2H- and 3H-labelled internal standards, plasma prostanoids were extracted by reversed-phase cartridges and purified by normal-phase high-performance liquid chromatography. The pentafluorobenzyl, methoxime, trimethylsilyl derivatives were formed. Negative-ion chemical-ionization mass spectra with methane as reagent gas show one intense peak at m/z (M - pentafluorobenzyl). This ion was used for selective-ion monitoring. Prostanoid plasma concentrations (pg/ml) in five healthy volunteers were: PGE2 2.0-10.4, PGF2 alpha 2.2-9.8, 6-keto-PGF1 alpha 0.6-1.8, and TxB2 3.0-45.3. However, there is evidence that the TxB2 values may frequently be falsely high because of ex vivo production during the sampling procedure.
D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D015237:Dinoprost; D015232:Dinoprostone; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D011453:Prostaglandins / Q000097:blood*; D011458:Prostaglandins E / Q000097:blood; D011460:Prostaglandins F / Q000097:blood; D013929:Thromboxane B2 / Q000097:blood
D011453:Prostaglandins; D011458:Prostaglandins E; D011460:Prostaglandins F; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D015237:Dinoprost; D015232:Dinoprostone