Simple and rapid quantitative high-performance liquid chromatographic analysis of plasma amino acids

Abstract

A simple and rapid high performance liquid chromatographic method for the determination of plasma amino acids was developed. The method uses minimal sample volume and automated online precolumn derivitization of amino acids with o-phthalaldehyde and fluorescent detection. Amino acids are separated by a simplified gradient without column heating. The assay is linear from 5 to 1000 micromol/L for all amino acids. Recovery of amino acids was between 91 and 108%, intra-assay coefficient of variation (CV) was 1-7%, and inter-assay CV was 2-12%. The simple sample preparation and minimal sample volume make the method useful for the quantitation of amino acids in both patient and experimental animal samples.

Figure

Typical chromatograms of amino acids in a standard (A) and in a human plasma sample (B). 1. aspartic acid, 2. glutamic acid, 3. asparagine, 4. serine, 5. glutamine, 6. histidine, 7. glycine, 8. threonine, 9. citrulline, 10. arginine, 11. alanine, 12. taurine, 13. tyrosine, 14. valine, 15. methionine, 16. norvaline, 17. isoleucine, 18. tryptophan, 19. phenylalanine, 20. leucine, 21. ornithine, 22. lysine.