Hydrolysis is a common degradation mechanism, which is facilitated by the presence of acids or bases in solution or on the surface of solids the liquid is in contact with. With solids in contact with liquids, the larger the surface area the greater the potential for hydrolysis. Irregular (Type A) & spherical (Type-B) HPLC phases all have by design very high surface to volume ratios plus Si-OH groups populate the surface. Even a fully end capped traditional phase can have 30 to 50% free silanols on its surface. Using photodiode array detectors and HPLC/Mass Spec has highlighted this degradation activity.
Certain analytical disciplines such as natural product bio-actives and forensic science have shown that 10 to 20% of bio-active compounds may hydrolyze quantitatively “on-column” due to the conditions inside the HPLC Column. Historic analyses were usually made by these disciplines, of degradation products and not the injected material due to this activity in the column.
Cogent TYPE-C Silica™ based products with silica-hydride surface (Si-H) are much less hydrolytically active than the ordinary phases with surface silanols (Si-OH) and may not hydrolyze certain compounds making it possible to detect and track injected quantities instead of the degradation products inside created in the column. This can be especially useful when seeking non targeted analytes.