Most of the Cogent HPLC columns have an upper pH use limit of 8. 

However short exposure and possible use depends on how concentrated the solution is, what the pH of the solution is, and how long the column is exposed to the base.

Trimethylamine (pKb 4.2/ pKa conjugate acid 9.81) is generally not compatible and not supported with these columns because under conditions of extended exposure, silica-based stationary phases will be susceptible to dissolution.  Once this occurs, the column is considered unusable and not repairable. You may observe changes in retention time and peak shape distortion as a result of the phenomenon.

Please refer to the following link for pH compatibility specifications of the Cogent HPLC phases and other related articles below.

Click HERE for Cogent TYPE-C HPLC Column Specifications including the Diamond Hydride.