A New Low Cost, Fully Automated Amino Acid Analyzer Using a Gradient HPLC

Abstract

Since the first generally useful, dependable amino acid analyzer was developed by Spackman, Stein, and Moore (1), a large number of investigators have modified and improved the original scheme for separation of amino acids. Resins, buffers, detection reagents, and hardware have all undergone major refinements in the past 24 years, although the mechanics have basically remained the same. In a sense, the only amino acid analyzer configuration which has deviated in a fundamental way from the original design was the system described by Piez and Morris (2) in I960. Rather than “switch” from one buffer to another, a complex buffer gradient was utilized to elute various amino acids. That system, requiring a multichambered gradient device (3) never really became as popular as the original system since the gradient maker had to be cleared and refilled after each run. The gradient system did not lend itself as readily to automation as the “step” buffer system where a simple valve switches from one buffer to another to another, etc., until the run is over and initial buffer conditions are reestablished.