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 phase cartridges and eluted with a step gradient of n-propanol in formate-pyridine buffer. Enkephalins are separated from metabolic products. Separation of α, β and γ-endorphin is demonstrated, and Met- and Leu-enkephalin are also separated. This inexpensive, reproducible method is useful in studies of neuropeptide metabolism, purification of synthesized peptides, separation prior to RIA, or concentration of neuropeptides. (author)