Complete separation and quantitative determination of DABTH-amino acid derivatives by isocratic reversed-phase high performance liquid chromatography

AbstractThe isocratic separation by reversed-phase HPLC of all DABTH-amino acid derivatives which are released by degradation of polypeptides with 4-N,N-dimethylaminobenzene-4'-isothiocyanate is described. The method allows an easy and quick identification and the quantitative determination of all derivatives in 30 min and includes the separation of isoleucine and leucine. Detection limit is 5 pmol at 436 nm. The solvent mixture is continuously recycled through the column, thereby reducing the solvent consumption considerably