• British Pharmacopoeia Volume V
  • Appendices
  • Appendix I A. General Reagents

Kieselguhr G

Kieselguhr GKieselguhr that has been treated with hydrochloric acid and calcined and to which has been added about 15% of calcium sulfate hemihydrate. The average particle size is 10 µm to 40 µm.

Complies with the following test.

Chromatographic separation Carry out the method for thin-layer chromatography, Appendix III A, using the substance being examined in a 0.27% w/v solution of sodium acetate to coat the plate and a mixture of 12 volumes of water, 23 volumes of propan-2-ol and 65 volumes of ethylacetate as the mobile phase but allowing the solvent front to ascend 14 cm above the line of application; the development time is about 40 minutes. Apply to the plate 5 µL of a solution containing 0.01% w/v of lactose, sucrose, d-glucose and d-fructose in pyridine. After removal of the plate, allow it to dry in air and spray with about 10 mL of anisaldehyde solution and heat for 5 to 10 minutes at 100° to 105°. The chromatogram shows four well-defined spots without tailing and well separated from each other.