British Pharmacopoeia Volume V
Appendices
Appendix I A. General Reagents

Silica Gel for Chromatography, End-capped Octadecylsilyl

Chromatographic reagent grade of commerce.

A very finely divided (3 µm to 10 µm) silica gel, chemically modified at the surface by the bonding of octadecylsilyl groups. To minimise any reaction with basic compounds it is carefully end-capped to cover most of the remaining silanol groups. The particle size is indicated after the name of the reagent in the tests where it is used.