Enhanced Peptide Purification via Novel
Orthogonal, Doped Reverse Phase Chromatography
Jürgen Machielse , †Prof. Dr. Kinkel , Andrea Wild , Tim O`Mara 
1. Zeochem AG, Uetikon am See, Switzerland
2. Former Prof. at TU Georg-Simon-Ohm, Nuremberg
3. Itochu Chemicals America Inc.
Peptides are important API’s for modern pharmaceuticals and have to be produced in industrial scale with increasing demand on separation costs.
RPC is the well-established chromatographic mode within the available tool-box of methods and procedures for the purification of this class of compounds in industrial scale production.
The paper will describe the beneficial use of Doped Reversed Phase packings in the repulsive-attractive mode compared to non-doped RP packings on crude peptides. The novel orthogonal Doped Reversed Phase materials combine the dual action of strong IEX groups (acidic or basic) and Reversed Phase ligands like octyl chains on the packing surface.
Usually, Mixed-Mode packings are applied under conditions which add the retention power of IEX groups by electrostatic attractive forces to the retention received from hydrophobic surface groups to the solutes. Both species, e. g. the peptide and the IEX group carry opposite charges.
In 2014, ETH-Zürich (Prof. Dr. M. Morbidelli et al) in cooperation of Zeochem AG have introduced the repulsive – attractive mode for peptide separation.
It can be shown that in the majority of all cases tested so far, improved selectivities and increased resolution at decreased retention time and solvent consumption can be obtained.