Simultaneous Amino Acid Analysis Based on 19F NMR Using a Modified OPA-Derivatization Method.

To provide alternative methods of analyzing amino acids without liquid chromatography, 19F NMR-based simultaneous and individual detection methods for amino acids using o-phthalaldehyde (OPA)-based 19F labeling have been developed. Since the chemical shifts of almost all 19F-labeled amino acids differ from each other, and they can be discriminated on the 19F NMR spectrum, simultaneous detection of amino acids has been successfully demonstrated. The discrimination pattern of the peak identical to that of the 19F-labeled amino acids was largely dependent on the chemical structure of the thiols having 19F nuclei, strongly suggesting that there is a large potential for clearer discrimination of amino acids by optimizing the thiol structure and/or combined use of thiols.