1996 Volume 45 Issue 4 Pages 315-320
A general method has been developed for the selective ultraviolet detection of amino acids using reversed-phase liquid chromatography. The method is based on the formation of copper(II)-amino acid complexes by the reaction of amino acid with copper(II) ions in an alkaline mobile phase through an in-line reactor containing copper metal. Seven amino acids were separated on a column containing C18-bonded vinyl alcohol copolymer gel (Asahipak ODP-50, 5μm, 250 × 6 mm i.d. ) and the alkaline mobile phase containing 10 mM hexadecyltrimethyl ammonium as an ion pair reagent (pH 11.0, 25 mM phosphate buffer). Copper metal (100200 mesh, 150 mg) was packed into the in-line reactor (4 × 4 mm i.d.). The detection was carried out at 255 nm. A detection limit of 800 pg (S/N=3) was obtained for proline.
