Analysis of monomeric alkyl- and arylchlorosilanes

The radioisotope carbon-14 was used to study the retention of carbon in the decomposition of alkyl- and arylchlorosilanes by wet methods. Losses by sample volatilisation were overcome by preliminary cooling in dry ice. Fuming sulphuric acid alone or in mixtures with fuming nitric acid was found to be the most effective oxidant of the acids tested. Examination of the carbon-containing silica residues by X-ray powder photography indicated that amorphous carbon was present but there was no evidence of silicon carbide.