Endcapping
A technique often used to minimize silanol activity on the surface of silica-based stationary phase after bonding of funtional groups. By reducing free silanols, peak tailing can be minimized, resulting in better peak shape. It is not a 100% process, thus a small number of silanols still remain. However, they are often non-reactive due to steric hinderance from the endcapping agent and funtional groups. Some manufacturers use multiple endcapping to further minimize silanol activity.