Microdetermination of carbon and hydrogen Automatic combustion in a dynamic system

An automatic combustion method has been developed for organic and organo-metallic compounds (5-10 mg samples), based on "wide tube" dynamic combustion in a turbulent oxygen atmosphere. Hydrocarbons, carboranes, transition metal carboran complexes, highly fluorinated compounds, silanes, siloxanes and cyclosilazanes, fluoroderivatives of alkyl phosphinic acids, high polymers, etc. have been analysed by it. Silver-plated pumice, magnesium oxide, fibrous asbestos and crushed quartz were used to absorb interfering elements. Advantages over the manual procedure are simplicity of procedure, rapid combustion of difficultly combustible or highly volatile compounds, and better reproducibility of the results. The overall combustion cycle takes 15 min. The standard deviation for hydrogen is 0.01-0.15 % and for carbon is 0.10-0.23 % (carbon content 20-95 %).