Comparative Liquid Chromatographic Studies for the Determination of Bioactive Peptides

Reliable and sensitive chromatographic methods have been developed and applied to determine derivatized di- and tripeptides: aspartame, carnosine, glutathione, alanyl-glutamine, and γ-glutamyl-cysteine. Photodiode-array detection was used for dansyl-chloride derivatives, while fluorescent detection was carried out for orthophthaldialdehyde derivatized peptides to obtain higher sensitivity. The sensitivity and detection limits were determined and compared in order to select the most efficient analytical method. Transition metal complexes [zinc(II), cadmium(II), silver(I), and copper(II)] with cysteine containing peptides were also determined with ultraviolet-visible detection. The structural identification was carried out by the analysis of the mass-spectra recorded with an atmospheric pressure chemical ionization method in separate chromatographic experiments.