Liquid chromatographic profiling is the use of chromatographic techniques to separate molecules by different physicochemical properties. It forms a key part of any protein, glycoprotein or peptide structural characterization investigation and it is a requirement of ICH Topic Q6B.
ICH Q6B is a regulatory document that details the requirements for protein characterization and is the approach accepted by the regulatory agencies. Regarding liquid chromatography analyses, ICH Q6B states:
Chromatographic patterns and data on the identity, homogeneity, and purity can be obtained by size exclusion chromatography, reverse-phase liquid chromatography, ion exchange liquid chromatography, affinity chromatography or other suitable procedures.
Therefore, as the guidelines state, liquid chromatographic profiles provide important information on the purity of the molecule and are used as a mechanism for separation of different species within a sample. These isolated species can then be collected for further structural and physicochemical characterization if necessary.