Resolution of the diastereomers of a large synthetic peptide by capillary electrophoresis using nonionic surfactants

A capillary electrophoretic method was developed for the determination of the diastereomeric composition of the bradykinin B2 antagonist, SB-238592-DB. The nonionic surfactant Brij 35 was demonstrated to be suitable for the baseline resolution of the three diastereoisomers of SB-238592-DB in the presence of a low pH phosphate buffer and small volume percentages of acetonitrile.