Rice husk derived silica aerogel as chromatographic packing material for colour separation of purple orchid (Cattleya bowringiana) flower

Abstract

There are a great number of packing materials commercially available for column chromatography such as silica gel, alumina and cellulose powder. In this study, silica aerogel prepared using rice husk ash is used as the packing material for colour separation of purple orchid (Cattleya bowringiana) flower. The colour fractions of Cattleya bowringiana extract had been successfully separated using silica aerogel prepared from rice husk ash by column chromatography. The silica aerogel was prepared by sol–gel and supercritical drying at temperature and pressure of about 250°C and 5·9 MPa (850 psi) respectively. The Cattleya bowringiana extract was applied to the silica aerogel column (BioRad 1 × 20 cm) for separation. Fractionation of the extract was done by elution with 50% aqueous methanol containing 0·05% trifluoroacetic acid. Three different colours: green, blue and purple were successively parted from the column.