Rapid separation of enkephalins and endorphins on Sep-Pak reverse phase cartridges

A simple, rapid method is described for separating neuropeptides. Samples were injected on Sep-Pak disposable reverse phase cartridges and eluted with a step gradient of n-propanol in formate-pyridine buffer. Enkephalins are separated from metabolic products. Separation alpha, beta and gamma-endorphin demonstrated, and Met- and Leu-enkephalin are also separated. This inexpensive, reproducible method a useful in studies of neuropeptide metabolism, purification of synthesized peptides, separation prior to RIA, or concentration of neuropeptides.