Abstract

Abstract The feasibility of injecting o-phthaldialdehyde/2-mercaptoethanol reagent and amino acid mixture simultaneously, from separate Injector vials in order to allow automation of HPLC pre-column amino acid derivative analysis was investigated. The modified duel injection system described proved to be successful. Reaction of amino acids and reagent takes place during flushing of the injection loop. This is immediately followed by the introduction of the formed derivatives into the main HPLC eluent stream leading to the chromatographic column. The described procedure gave reproducible results with no loss in sensitivity. Further established was the optimum pH of reagent for derivative formation and of eluents for the separation of derivatives.