DETERMINATION OF TOTAL FLUORINE IN 5 COAL REFERENCE MATERIALS BY PROTON-INDUCED GAMMA-RAY EMISSION-SPECTROMETRY

The direct non-destructive proton-induced gamma-ray emission (PIGE) te chnique with a germanium detector was applied to the determination of total fluorine concentration in five coal reference materials (BCR 30, NIST 1632b, NIST 1635, SARM 20 and USGS CLB-1). Duplicate analyses we re made from five randomly selected bottles of each coal. Individual d ata are presented and some problems (calibration, proton stopping powe r, effects of sample heating by the proton beam, background estimation ) which were encountered during this study are discussed. Sensitivity and reproducibility of the determinations, and homogeneity of the coal samples with respect to fluorine contents by analysis of variance wer e investigated. The present data are also compared with the few publis hed values for these reference samples, including other PIGE data. The use of synthetic standards and spiked samples in the present study su ggested that the PIGE method was more accurate than other techniques.