Applicability of predictive models to the peptide mobility analysis by capillary electrophoresis–electrospray mass spectrometry

The prediction of peptide mobility by capillary electrophoresis (CE) coupled to electrospray mass spectrometry (MS) is studied in order to verify the validity of the semi-empirical models developed in classical CE. This work relies on the experimental determination of the electrophoretic mobilities of 68 peptides, different in charge and in size. The results indicate that the prediction is possible in CE–MS experiments, in spite of the restraints inherent in the coupling conditions. The best fit of experimental data was obtained with the Offord’s model. The efficiency of the model was confirmed by the analysis of a peptide mixture in CE–MS.