Harnessing the power of electrophoresis and chromatography: Offline coupling of reverse phase liquid chromatography-capillary zone electrophoresis-tandem mass spectrometry for peptide mapping for monoclonal antibodies.

•A RPLC–CZE-MS/MS platform was used for the first in-depth mAb characterization.•RPLC–CZE–MS/MS covered more sequence, peptides & PTMs, than RPLC-MS/MS & CZE-MS/MS.•It was more informative than even the combined datasets of RPLC-MS/MS & CZE-MS/MS.•1D RPLC and CZE methods are thus not enough for characterization of mAbs.•RPLC–CZE–MS/MS should be added to the analytical toolbox for mAb characterization.