Liquid Chromatography of Amino Acids and their Derivatives

Abstract

Since the classical studies of Moore and Stein [1,2] the separation of amino acids on cation exchange resins has been the method for their quantitation in both hydrolysates and physiological fluids. Subsequently the ease with which this could be accomplished was greatly improved by the development of an automatic analyser [3]. However over the last few years the technologies associated with high performance liquid chromatography (HPLQ have been applied with increasing success to the determination of amino acids and their derivatives. Much early work in HPLC involved investigating and ‘re-discovering’ much that was already well known to users and manufacturers of amino acid analysers. For example the comprehensive studies on the chromatography of amino acids performed by Hamilton [4–6] in the late 1950s are reflected a decade later in the HPLC literature. Similarly it is only in the 1980s that HPLC manufacturers and users are advocating post-column derivatization to enhance both selectivity and sensitivity and developing a theoretical understanding of the mechanisms involved. Modern HPLC equipment has only recently reached the level of sophistication common in amino acid analysers ten years ago. It should be stressed that cation-exchange chromatography of amino acids represents one specific application of the general analytical technique of liquid column chromatography and that high performance (or high pressure) liquid chromatography is simply the terminology applied to the technique as currently optimized.