Digestion methods for advanced ceramic materials and subsequent determination of silicon and boron by inductively coupled plasma atomic emission spectrometry

Various wet chemical digestion procedures, such as pressure digestion, microwave-assisted pressure digestion and decomposition via alkali fusion, were applied to different ceramic powders including Si3N4, BN and a new advanced ceramic material. The last powder was prepared from novel precursor compounds by pyrolysis of inorganic polymers, and consists of Si, B, N and C. The precision obtained in the determination of the main components Si and B by sequential ICP-AES varied from 0.6 to 3% (m/m) for Si and from 0.2 to 2% (m/m) for B depending on the digestion method and the ceramic material. Special attention was also given to the recovery of Si and B, which is in most cases 100% within the standard deviation, and to the time consumption for the different digestion methods, which varied between 10 min and 23 h. It will be shown how the stoichiometry of the novel Si-B-N-C ceramic SiBN2.35C0.78 can be determined reliably by ICP-AES analysis for Si and B. The C, N and O were evaluated by carrier gas heat extraction.