Thermo-Responsive Stationary Phases for High Performance Liquid Chromatography (HPLC)
In classical liquid chromatography, proteins are generally separated by employing RP-18 columns in the presence of acetonitrile or other organic solvents at low pH buffers as mobile phase. However, the presence of organic solvents often leads to the total denaturation of proteins, while acidic environments are often destructive to the activity of many enzymes. One possible way to prevent the denaturation of proteins in liquid chromatography is to use purely aqueous mobile phases. However, RP columns do not function well under such conditions.
Recently a novel method has been developed by Kanazawa et al, in which the stationary phase changes its surface properties from hydrophilic to hydrophobic as a response to temperature. The main advantage of these temperature sensitive stationary phases is that they can separate mixtures of biomolecules (large peptides, proteins) in a pure aqueous environment under isocratic conditions. Thus, the harsh conditions normally associated with protein separation and denaturation by employing RP-18 columns in the presence of organic solvents gradients can then be avoided.