The present application discloses a chromatographic process for separating protein components of a protein-containing solution, said solution comprising an insulin peptide and one or more di- or polyvalent metal ions, said insulin peptide being capable of self-association and/or structural change in the presence of di- or polyvalent metal ions, said process comprising the steps of: a) applying the protein-containing solution to a column of a chromatographic solid phase material, wherein the loading of the insulin peptide is at least 6.0 g per litre of column volume (g/Lcv); and b) eluting the insulin peptide from said solid phase material by means of an eluent having a pH of at the most 8.5; and collecting a pool of the insulin peptide corresponding to at least 75% by weight of the insulin peptide applied to the column in step (a).