Analysis of macromolecular branched chain polypeptides by capillary electrophoresis and micellar electrokinetic chromatography

Amphoteric poly(Lys‐[Glu1.0‐DL‐Ala4.1]), (EAK) and anionic poly(Lys‐Ac‐Glu0.98‐DL‐Ala3.98]), (AcEAK) branched chain polypeptides were analyzed by capillary electrophoresis (CE) and micellar elektrokinetic chromatography (MEKC) in the following buffers. A1: 0.25 N triethyl ammonium phosphate (TEAP) buffer (pH 2.25); A2: 100 mM sodium dodecyl sulfate (SDS) in buffer A1; B1: Na‐borate buffer (pH 7.7); B2: 100 mM SDS in buffer B1; C1: Na‐borate buffer (pH 11.0); C2: 100 mM SDS in buffer C1. Both EAK and AcEAK could be separated by a CE mechanism at pH 2.25 and by an MEKC mechanism at pH 11.0. Optimum results were achieved with CE in buffer A1 and with MEKC in buffer C2.