Determination of deuterium-labeled phenylalanine and tyrosine in human plasma with high pressure liquid chromatography and mass spectrometry.
A method is presented for the recovery of deuterated phenylalanine and tyrosine from human plasma. Phenylthiohydantoine derivatives are formed (Edman reaction) which are separated and isolated by high pressure liquid chromatography. The relative concentration of the deuterated amino acid is determined by mass spectrometry. The results obtained from a healthy person after oral loading with 40% monodeuterated L-phenylalanine are presented. The method appears to be suitable for in vivo studies of phenylalanine metabolism in humans.
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003903:Deuterium; D006801:Humans; D007553:Isotope Labeling; D013058:Mass Spectrometry / Q000379:methods; D010649:Phenylalanine / Q000097:blood*; D010669:Phenylthiohydantoin; D014443:Tyrosine / Q000097:blood*
D010669:Phenylthiohydantoin; D014443:Tyrosine; D010649:Phenylalanine; D003903:Deuterium