Direct determination of metallic impurities in graphite by EDXRF.

Energy dispersive X-ray fluorescence (EDXRF) methods have been developed for the direct determination of 14 trace metallic impurities in graphite powder without any need for sample dissolution. Using synthetic standards, calibration curves were established for different elements after optimizing the spectrometer parameters. Two synthetic samples were analyzed to evaluate the performance of the developed analytical methods. The estimates for most of the analytes were in good agreement with the added amounts. Three graphite powder samples were analyzed by the present method as well as by D.C. arc emission spectrometric technique for comparison and the agreement between the analyte values determined, using both methods was good. Samples in pellet form were analyzed using a separate calibration with standards in pellet form. The present method is rapid, as it alleviates the need for any chemical treatment and gives good precision. Copyright 2009 Elsevier Ltd. All rights reserved.