Capillary liquid chromatography-fast atom bombardment mass spectrometry using a high-resolving cation exchanger, based on a continuous chromatographic matrix. Application to studies on neuropeptide peptidases.
Hyphenated mass spectrometric techniques such as LC-MS are advantageous over standard MS methods, because they provide increased sensitivity and minimize signal suppression by other compounds present in the reaction mixture. Recently, we have introduced so-called continuous beds, and applied this technique to prepare a 0.32 mm I.D. cation-exchange capillary column, in order to separate the reaction product substance P(1-7) after proteolytic cleavage of substance P by an endopeptidase recovered from human cerebrospinal fluid. The use of a volatile buffer for elution provides very good flow stability. Ion-exchange microcolumns may be particularly useful for the separation of those peptides that co-elute in reversed-phase chromatography because the separation mechanisms of these two methods are different.