Analysis of Amino Acids:

Commercial amino acid analyzers have been available for many years. They work on the principle of HPLC and are widely used for the separation analysis of a large number of amino acids from a mixture as they form cations by adding protons in the pH range below their isoelectric point. They are separated on a cation exchange column where more acidic component emerges first and the most basic in the last. A typical chromatogram of 17 amino acids containing 10 nM of each is shown in Figure. The complex of amino acid-ninhydrin is photometrically measured at 570 nm.