Fluorometric assay of secondary amino acids

A method is described for the conversion of secondary amino acids to primary amines which can be assayed with fluorescamine (I). Secondary amino acids undergo oxidative decar?ylation when reacted with halogenating agents. The resulting imines are hydrolyzed to primary amines, which are subsequently allowed to react with fluorescamine (I) to yield fluorescent pyrrolinones (II). This reaction sequence provides an efficient fluorometric assay for secondary amino acids. Thus, the fluorescamine procedure is now applicable to the full array of natural amino acids.