Capillary electrophoresis-mass spectrometry for the analysis of biopharmaceuticals

Developments in the fields of protein chemistry and pharmaceutical biotechnology have increased the demand for suitable analytical techniques for the characterization of intact proteins. Capillary electrophoresis (CE) coupled to mass spectrometry (MS) has proven to be a powerful tool for this purpose because it combines high separation efficiency with mass selectivity. This article provides an overview of CE-MS method development work in our laboratory for biopharmaceutical analysis applying noncovalent capillary coatings to prevent protein adsorption. Technological aspects with respect to the use of CE-MS interfaces and types of noncovalent capillary coatings applied are treated. Furthermore, some typical examples are highlighted to demonstrate the versatility of CE-MS for the analysis of biopharmaceuticals. These include the analysis of recombinant human growth hormone, recombinant human interferon-β-1a, recombinant human erythropoietin and protein-drug conjugates. We concluded that there is strong potential for CE-MS systems using noncovalent coated capillaries for purity and stability analysis of biopharmaceuticals.