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Comparison of Orthogonal Mass Spectrometry Platforms for the Determination of Amino Acid Concentrations in Human Plasma Certifying NIST Standard Reference Material 1950
Published
Author(s)
Mark S. Lowenthal, Karen W. Phinney, Elizabeth A. McGaw
Abstract
Absolute concentrations of amino acids in a human plasma pool were determined independently using four quantification methods. Orthogonal separation schemes (LC, GC, or GCxGC) and detection systems (triple quadrupole or time-of-flight mass spectrometers) are shown to demonstrate excellent consistency between platforms for quantifying 18 amino acids in NIST Standard Reference Material (SRM) 1950 Metabolites in Human Plasma using a well-characterized isotope dilution (ID) quantification method. Experimental values were acquired to the rigorous standards associated with National Institute of Standards and Technology (NIST) measurement procedures and compare closely with reference values in plasma from literature publications. Individual amino acid concentrations in plasma varied by over an order of magnitude ranging from 1.869 µg/g to 28.4 µg/g (7.940 µmol/L to 326 µmol/L). Average variability between experimental amino acid concentrations (excluding cysteine) among all methods was 6.7%. Certified mass fraction values for amino acids in NIST SRM 1950 will be established from statistically weighted means of all experimental results.
Lowenthal, M.
, Phinney, K.
and McGaw, E.
(2010),
Comparison of Orthogonal Mass Spectrometry Platforms for the Determination of Amino Acid Concentrations in Human Plasma Certifying NIST Standard Reference Material 1950, Journal of Chromatography A, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=903819
(Accessed October 9, 2025)