The Chromatographic Separation of Dimethylaminoazobenzenesulfonyl (DABS)-Amino Acids

Chang et al. ¹ demonstrated in 1981 that amino acids labeled with dimethylaminoazoben-zenesulfonyl chloride (DABS-CI) could be separated using a Zorbax® ODS column and detected in the visible region. A technique described later which gave a complete baseline separation of DABS-amino acids employed a LiChrosorb® RP-18 column operated at 50°C in conjunction with a complex gradient based on dimethylformamide, acetonitrile, and phosphate or acetate buffer. ² Although different columns such as Supelcosil® LC-18 and Vydac® C-18 gave complete separation of DABS-amino acids, Knecht and Chang preferred a Merck C-18 column, principally because of its lower cost. ³