Premium
Determination of phenylalanine in human serum by isotope dilution liquid chromatography/tandem mass spectrometry
Author(s) -
Lee Hwashim,
Park Sangryoul,
Lee Gaeho
Publication year - 2006
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2528
Subject(s) - chemistry , isotope dilution , chromatography , phenylalanine , tandem mass spectrometry , derivatization , selected reaction monitoring , certified reference materials , mass spectrometry , liquid chromatography–mass spectrometry , high performance liquid chromatography , detection limit , analyte , amino acid , biochemistry
Abstract Isotope dilution liquid chromatography/tandem mass spectrometry (ID‐LC/MS/MS) has been developed as a candidate reference method to determine the level of phenylalanine in human serum. The advantages of this method include a simple sample preparation without derivatization, selective detection of analytes, and the use of an isotopic analogue as an internal standard. Phenylalanine and its isotopic analogue, phenylalanine‐ring‐ 13 C 6 , were monitored at the transitions m/z 166.2/120.2 and 172.2/126.2 in the multiple‐reaction monitoring (MRM) mode, respectively. The expanded uncertainty of the measurement result of phenylalanine in the serum was approximately 1.2% within a 95% confidence level. A standard reference material, with a certified value of phenylalanine, was analyzed in order to verify this method. The result obtained by the ID‐LC/MS/MS method differed somewhat from the certified value, but agreed well with the gravimetric value. The measurement result of phenylalanine in serum by ID‐LC/MS/MS was compared with the results from the commercial HPLC method, which was carried out in clinics. The results from the commercial HPLC method showed inconsistent results with each other. The busted results from the commercial HPLC method suggest that it should be possible to trace the results of the commercial fields to well‐characterized reference materials or methods. Copyright © 2006 John Wiley & Sons, Ltd.