Another unique feature of the Cogent TYPE-C Silica™ based products is that the silica surface, with silicon-hydrides, can act independently of the bonded phase giving it the ability to interact differently with non-polar to mid-polar compounds.

An example of this mechanism is the work done by MicroSolv on Metformin and Glyburide; two anti-diabetic drugs of vastly different partition coefficients. When separating these two compounds as a single mixture, the Cogent TYPE-C™ Silica column produces good separation of the compounds with good peak shape for Glyburide and alightly tailing peak shape for Metformin. All other features of the TYPE-C™ series are evident in the separation. When the Cogent UDC-Cholesterol™ column is used instead of the Silica column the peak shape is excellent for both compounds. This suggests that the bonded phase interacts differently from the silica surface and that the silica surface is acting on the compounds similarly in both columns. For a complete review of this work and how to apply it, please contact us. Click here for a detailed description of how this works.