Complete high-performance liquid chromatographic separation of 4-N,N-dimethylaminoazobenzene-4′-thiohydantoin and 4-dimethylaminoazobenzene-4′-sulphonyl chloride amino acids utilizing the same reversed-phase column at room temperature

Abstract

Reversed-phase high-performance liquid chromatographic methods for the complete separation of all 4-dimethylaminoazobenzene-4′-sulphonyl chloride and 4-N,N-dimethylaminoazobenzene-4′-thiohydantoin amino acids on the same Supelcosil LC-18 column at room temperature are described. The procedures are simple and reproducible, and the systems are easily interconvertible. The use of a fixed-wavelength detector at 436 nm permits amino acid analysis at levels lower than 1 pmol with a stable baseline.