Diatomaceous Support, Acid-washed

Diatomaceous Support, Acid-washed Diatomaceous earth for gas chromatography

White or almost white, fine granular powder, made up of siliceous frustules of fossil diatoms or of debris of fossil diatoms, practically insoluble in water and in ethanol (96%). The substance may be identified by microscopic examination with a magnification of × 500. The substance is purified by treating with hydrochloric acid and washing with water.

Particle size Maximum 5% is retained on a sieve No. 180. Maximum 10% passes a sieve No. 125.