Separation and detection of closely related endorphins by liquid chromatography-electrochemistry

The specific aim of this study was to investigate the selectivity of liquid chromatography--electrochemistry for minor variations in the structure of small endorphins. Using isocratic mobile phases, chromatographic conditions were established for the separation of a series of closely related endorphins. Hydrodynamic voltammetry showed that each peptide exhibited a characteristic oxidative behavior that was also reflected in peak current ratios. Changes in a small moiety altered both the chromatographic behavior and electroactivity of these neuropeptides.