• Silica derived from inorganic sources (TypeA)
must undergometals removal procedures to create
usablematerials forHPLC chromatography.
• Refinedmetal removal processes using the typeA
silica can create a base deactivated silica.
• TypeB silica is derived from “metal free” organic
sols.Metals content is due topost-particle
contamination.
• Certainprocesses canproduce a base deactivated
silica that rival typeB formetals content.
