Determination of Peptides by High Performance Liquid Chromatography with Coulometric Detection Following the Biuret Reaction

Abstract

An ultramicro method is described for the determination of peptides by high performance liquid chromatography with coulometric detection. The method is based on the formation of electrochemically oxidizable copper(I) ion by reaction of peptides with copper(II) ion in an alkaline medium containing ammonia in postcolumn reaction. Di- and tripeptides used as model compounds (6 species) are separated on a reversed phase column. The detection limit was 200pg for glycylglycylglycine. Prolylglycine was detected, but not glycylproline, which has no amide-bond in the molecule.