CERTIFIED REFERENCE MATERIALS FOR THE QUALITY-CONTROL OF FLUORINE IN COAL, FLY-ASH AND CLAY

A group of laboratories has worked in various intercomparisons in the frame of the BRC-programme (European Commission) to improve their meth ods for fluorine determination, especially for coal analysis. These ex ercises allowed to detect and remove sources of error. Methods were im proved to such an extent that the certification of fluorine and chlori ne in different materials could be envisaged and the BCR consequently decided to produce coal, fly ash and clay materials certified for thei r F content. In addition, chlorine was certified in the fly ash CRM.