Rapid Analysis of Trace Amounts of Amino Acid Derivatives by a Formyl Group-Installed Crystalline Sponge

The Industries need techniques for the rapid structure analysis of amino acid derivatives. The amino acid derivatives are sometimes produced as impurities in the industrial production processes, and cause toxicity problems. Herein, we report the crystalline sponge (CS) method analysis of variety of amino acids using a formyl group installed CS crystal. Most amino acids possess a primary amino group, which can form Schiff-base with the formyl group under mild conditions. Thus, the formyl group installed CS crystal can efficiently capture the amino acids via Schiff-base formation. We successfully analyzed derivatives of 18 proteogenic amino acids, 6 non-proteogenic amino acids, and 4 dipeptides using the formyl group installed CS. We thus believe that the protocols shown in this study would serve the need of the industries.