A sample of toluene-soluble extract from brown coal or lignite obtained by the procedure describes in ISO 975 is extracted with acetone at a temperature of 18 to 22 °C. The soluble fraction is filtered or centrifuged off and after evaporation of the solvent dried to constant mass. The percentage of acetone-soluble material is calculated from the mass of reidue after drying.
Status : WithdrawnPublication date : 1985-12
Edition : 2Number of pages : 2
Technical Committee:Methods of analysis