What is the role of arginine as a mobile phase additive in GFC separations?

Arginine can perform multiple functions within a GFC separation of proteins:

• Tt can reduce secondary interactions by capping silanol groups, and hence reduce the tailing of basic proteins.
• It will reduce the tendency of proteins to aggregate, so if aggregation studies are being conducted then it is best avoided.
• It will also alter the hydrodynamic volume of proteins, so their retention can be greatly impacted by the use of arginine in the mobile phase - this can either be due to salting in (effectively denaturing the protein) or salting out (encouraging it to interact with the diol phase). In both cases this would generally lead to an increase in retention time of the proteins.