Coupling non-denaturing chromatography to mass spectrometry for the characterization of monoclonal antibodies and related products.

The hyphenation of non-denaturing liquid chromatographic (LC) modes (ion exchange (IEX), size exclusion (SEC) and hydrophobic interaction chromatography (HIC)) with mass spectrometry (MS) has attracted significant attention in the last few years. The inherent problem of these couplings is that non-denaturing LC separations have tended to use non-volatile mobile phase additives. Indeed, classical methods have not been directly compatible with MS. Therefore two approaches can be used to address this challenge: (1) finding innovative volatile mobile phases or (2) adding a desalting step prior to MS detection via the use of multidimensional LC. These two possibilities have been applied to the characterization of charge-, size- and hydrophobic variants of various monoclonal antibodies (mAbs) and related products and have been reviewed in this paper.