The present disclosure is directed to methods of separating a chelator from a mixture and measuring the concentration of the chelator in the mixture using a chromatography column. Such methods can be useful in adjusting the concentration of a chelator of a composition comprising a protein.

The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for its preparation and separations devices containing the chromatographic material; separations devices, chromatographic columns and kits comprising the same; and methods for the preparation thereof. The chromatographic materials of the invention are superficially porous chromatographic particulate materials comprising sized less than 2 microns.