There are several reasons why the Cogent TYPE-C™ Silica is preferred to HILIC, Mixed Mode, or Ion Exchange phases in terms of total cost to the end user.
1. With HILIC columns, you need to have 25–50 mM concentration of a salt present in the mobile phase in order to get polar compounds to elute from the column. In contrast, you only need to use ~0.05–0.1% with TYPE-C Silica columns. This becomes a significant advantage in both LC-MS and preparative applications. You do not want to have too much salt in your MS because maintenance will need to be done more frequently on it. This leads to additional costs to the laboratory not only in terms of the maintenance service performed but also in terms of instrument downtime. For preparative applications, the higher salt content used with HILIC, mixed mode, or ion exchange columns leads to additional isolation processes of the collected fractions in the evaporator (5–6 times). The more repeated isolation attempts are required, the lower the yield and throughput. With Cogent columns, you may only need to do perform one evaporation due to the lower salt content. Hence, these columns can save your laboratory time and money (some customers have seen increases in yields, up to 100X).
2. HILIC and ion exchange phases require lengthy re-equilibration times in order to restore the stationary phase surface environment (adsorbed water and/or buffer components). With Cogent columns, the retention is not dependent on partitioning with an adsorbed mobile phase. Therefore, equilibration is rapid (1/10th the times of other columns) and uses less solvents as well. You also get better run-to-run precision for your analyte retention times.
3. The Cogent columns are more versatile. You can use them in RP, ANP, or ONP modes without hysteresis or damage to the columns. HILIC columns for example can only retain polar compounds and are not suitable for reversed phase analyses. With TYPE-C Silica, one column can do the job of several.