ONLINE CAPILLARY ELECTROPHORESIS MASS-SPE CTROMETRY FOR DETERMINATIONOF PEPTIDE MIXTURE AND PROTEIN MIXTURE

The influence of uncoated, coated linear polyacrylamide(LPA) and amino -coated capillaries on the separation of five peptide mixtures, includ ing angiotensin I, II, III, substance P and somatostain, was studied. The results showed that the peptide mixtures could not be separated co mpletely in uncoated capillary by volatile buffer which was suitable f or the MS analysis, whereas they could be separated in LPA and amino c oated capillary by pH 5.0 and pH 4.5 NH4Ac buffer respectively. In add ition, the above peptide mixtures, protein mixtures comprised of myogl obin and carbonic anhydrase II, tryptic digests of erythropoietin, wer e separated and characterized by capillary electrophoresis-mass spectr ometry(CE-ESI-MS) with electrospray ionization interface. The factors affecting the determination in CE-ESI-MS were also discussed.