A new X-ray fluorescence
(XRF) method is proposed for sample preparation
and impurity quantification for elements heavier than sodium in carbon
materials. The analysis is suitable for various materials including
amorphous ones, such as petroleum cokes, with an impurity content
higher than 0.01%. We compared a new method with the regular additive
method to measure impurities in electrode graphite and petroleum coke.
The XRF-based method provides the same sensitivity and accuracy and
much greater reproducibility of the analysis results for variations
in the sample mass, its density, and coverage by exciting X-ray radiation.
The method does not require changes in the instrument software and
is easily implemented on commercial analytical equipment.