Yes, we have done extensive testing in our labs and in real world use around the world and have proven that the Cogent Silica-C™ columns are stable even in the presence of water. However, these columns are designed and specified for Normal Phase and Aqueous Normal Phase HPLC and not for Reversed Phase. But the only […]
Yes, if you develop a method that is optimized with the Cogent Silica-C™ columns compared with an ordinary silica column, the retention times are generally much more reproducible. The reason is most likely that when using ordinary silica columns the uptake of water changes from run to run and the retention often changes. Since the […]
Yes, although this is not easy with ordinary silica columns due to solvent de-mixing & water uptake, the Cogent Silica-C™ column is not limited by this and is easy to use.
The triethylamine (TEA) additive is compatible with Silica-C™ columns in the sample diluent or mobile phase as long as the concentration is not excessive and the mobile phase pH is kept within the specifications of the column (pH must not exceed 7.0). Specifications for Silica-C HPLC columns More information on Cogent Silica-C HPLC columns
Changing Retention Times and a peak Showing up in my Blank with a Cogent Silica-C Column. What can be the issue?
I am seeing changing retention times and a peak showing up in my blank using the Cogent Silica-C column in normal phase. What can be the issue? Suggestion: It is most likely a Matrix effect. You should wash the Column with a reasonable concentration of the Strong Solvent of your Mobile Phase, with it being […]
No, the Cogent Silica-C™ column is totally inorganic and is made completely of silicon, hydrogen and oxygen. Any apparent retention of non polar compounds you may observe is most likely aqueous normal phase retention mechanism and your method.
For all new Cogent TYPE-C™ HPLC columns with the exception of new Diamond Hydride™ columns, all one needs to do is run 7-10 column bed volumes of your mobile phase through the column at your normal flow rate. Then it is best to inject a known standard and repeat the injections until duplicate chromatograms are […]
Yes, it is and it has all the advantages of ordinary, market leading high purity, type-B silica supports for HPLC.
The biggest difference is the surface chemistry and how it will benefit you. The dominance of silicon hydride (Si-H) groups instead of the “silanol group” (Si-OH) common to all irregular or spherical Type A & B silica based phases changes the general character of the column; ie solvents will adsorb and desorb differently and much […]