ABSTRACT
A recently described approach to the precolumn derivatization and analysis of amino acids is based on the formation of the phenylthiocarbamyl derivatives. The technique was first used by Koop et al. 1 for the analysis of free amino acids liberated by carboxypeptidase Y digestion of peptides from cytochrome P-450. The phenylthiocarbamyl derivatives are ob-tained by reaction of the amino acids with phenylisothiocyanate, the reaction being essentially complete in a few minutes at ambient temperature. 2 Reaction times as short as 5 to 10 min can be used on a standard amino acid mixture with little change in yield. 3 After the reagent is removed from the reaction mixture under vacuum, the derivatized amino acids can be stored dry and frozen for several weeks without appreciable degradation.
