Determination of impurity elements in high purity graphite by inductively coupled plasma atomic emission spectrometry after microwave decomposition

A high purity graphite powder was completely decomposed with a mixture of nitric and sulfuric acids using an open microwave digestion system. The excess nitric acid remaining in the solution was evaporated off using the same system. The sample solution was diluted with water and analyzed for the determination of impurity elements (Li, Na, K, Mg, Ca, Sr, Al, Fe, Ni, Cr, Ti, V) by inductively coupled plasma atomic emission spectrometry (ICP-AES). The analytical results for the elements in standard samples agreed well with those by other methods.