Recommended method for the analysis of amino acids in biological materials.

Fifty-five ninhydrin-positive compounds in physiological fluids were determined with a Hitachi Model KLA-5 amino acid analyzer by a two-column chromatographic procedure. Both columns were packed with Hitachi Custom 2618 ion-exchange resin. The total analysis time was 9.5 h. In this procedure, particularly glucosamine, mannosamine and galactosamine were separated completely from normal "protein" amino acids, and NG-monomethylarginine, NG, NG-dimethylarginine and NG,NG-dimethylarginine, which were present in the myelin basic protein of several species and excreted in human urine, were separated from other basic amino acids. The method is useful for various applications with biological materials.