Gas chromatographic–mass spectrometric method for quantitation of phenylalanine and tyrosine in serum

• Published in: Journal of chromatography. B, Biomedical sciences and applications Vol. 762; no. 2; pp. 127 - 136
• Main Authors: Laurens, J.B, Mbianda, X.Y, Ubbink, J.B, Vermaak, W.J.H
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25.10.2001; Elsevier Science
• Subjects: Aminoacids, peptides. Hormones. Neuropeptides; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Fetal Blood - chemistry; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry - methods; Humans; Infant, Newborn; Phenylalanine; Phenylalanine - blood; Phenylketonuria; Proteins; Reference Standards; Reference Values; Tyrosine; Tyrosine - blood; Tyrosine; Phenylalanine; Phenylketonuria; Human; Gas chromatography; Biological fluid; Associated technique; Newborn; Investigation method; Aminoacid; Serum; Mass spectrometry; Quantitative analysis
• ISSN: 0378-4347; 1387-2273
• DOI: 10.1016/S0378-4347(01)00339-5

A validated gas chromatographic–mass spectrometric method for quantitation of phenylalanine and tyrosine in serum is described. Quantitation of phenylalanine and tyrosine with a non-labelled non-endogenous internal standard, l-2-chlorophenylalanine, compared favourably with isotope dilution mass spectrometric quantitation. The 95% reference ranges for phenylalanine, tyrosine and the phenylalanine–tyrosine molar ratio in neonate cord blood serum were determined by isotope dilution mass spectrometry and were found to be 77.1–144.7, 33.3–109.3 μmol/l and 1.1–3.0, respectively.