Direct determination of trace elements in coal: Wavelength‐dispersive X‐ray spectrometry with matrix correction using compton scattered radiation

Abstract

AbstractAn X‐ray flourescence method is described for the direct determination, without pretreatment, of up to 55 trace elements in coal and coal‐derived materials. A single assay specimen is prepared by blending finely crushed sample with a binder and briquetting. Calibration is effected by a suite of synthetic calibration standards prepared from spectrographically pure materials blended into graphite. Variations in ash and sulphur content required matrix absorption corrections to analyte and background intensities, which were achieved by use of relationships with the measured Compton scattered radiation. Prior knowledge of or assumptions concerning the composition of the coal are not required. Accurate results are presented for three NBS coal standard reference materials. Certain elements (including TI, Hg, Te, In, Cd, Ag and most rare earths) are normally present in coal at levels below the detection capability of the described method and require quantification by alternative techniques.