On-line HPLC analysis of PTH-amino acids derived from Edman degradation of proteins and peptides: Optical sensor controlled sample injection

Abstract

A new principle in the system of identification and quantitation of amino acid phenylthiohydantoins derived from automated Edman degradation of proteins and peptides is described. The beginning of the on-line HPLC analysis of PTH's, the actuation of the valve and the sample injection are controlled by an optoelectronic sensor placed at the sample loop outlet. At the moment the loop has been loaded the sensor actuates the injection valve thus starting the chromatography run. This arrangement eliminates the possibility of incomplete (irreproducible) loading of the loop or of void injection. The chromatographic separation of the PTH's is carried out by isocratic elution.