Gas chromatographic-mass spectrometric method for quantitation of phenylalanine and tyrosine in serum.
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 micromol/l and 1.1-3.0, respectively.
Laurens
J B
JB
Department of Chemical Pathology, Faculty of Medicine, University of Pretoria, South Africa. jlaurens@medic.up.ac.za
Mbianda
X Y
XY
Ubbink
J B
JB
Vermaak
W J
WJ
D005312:Fetal Blood / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D010649:Phenylalanine / Q000097:blood*; D012015:Reference Standards; D012016:Reference Values; D014443:Tyrosine / Q000097:blood*
D014443:Tyrosine; D010649:Phenylalanine