Determination of Kynurenine in Human Plasma by Gas Chromatography/Negative Ion Chemical Ionization Mass Spectrometry

Abstract

A sensitive method was developed for the determination of deuterated and non-deuterated kynurenine, one of the major metabolites of tryptophan, using gas chromatography/negative ion chemical-ionization mass spectrometry. Kynurenine was prepurified with an AG 50W × 2 cation-exchange column and then converted to pentafluoropropionyl-methyl-derivative. It was isolated and determined by selected ion monitoring (SIM). This method was applied to measurements of deuterated and non-deuterated kynurenine in human plasma after oral administration of L-tryptophan-2, 4, 5, 6, 7-d₅.