These early spherical phases then evolved to type B spherical phases, which had the added benefit of low trace metals in the silica, thereby reducing the impact of silanols ( through reduced electron withdrawal enhancement of the silanol activity ) on peak tailing with certain compounds.

TYPE-C™ takes this evolution to reduce silanol activity one stage further. With a bonded and fully end-capped type B phase approximately 30%-50% of the available silanols ( approximately 20% of the surface ) are still non end capped. With TYPE-C™, hydride replaces silanol for at least 95% of the available silanol activity, thus the resulting 0-5% available silanol activity is up to ten times less than a fully end capped type B phase.