Abstract
Methylisothiocyanate reacts with the amino group of amino acid in alkaline solution to give methylthiocarbamyl amino acid. This is converted to the methylthiohydantoin derivative (MTH-amino acid) by subsequent acidification.
Gas chromatographical identification of 20 amino acids were examined by making MTH-amino acids. Among them, ten amino acids (glycine, alanine, valine, leucine, iso-leucine, proline, methionine, phenylalanine, serine and threonine) were successfully identified. Aspartic acid and glutamic acid could be identified as the methyl esters of the MTH-amino acids.