Micro Dumas combustion

Combustion Calorimetric bomb (Berthelot), oxygen flask (Schoniger), Wickbold apparatus, cold plasma incinerator, micro-Dumas combustion (CHN analyser), sulfur-specific analysers (S, C, N, O), pyrochemiluminescence... 

In Micro Dumas combustion (CHN analysis) the sample is vaporised and carried by a stream of CO2 over nickel oxide at 1000 °C to oxidise the sample to CO2, H2O and N2. Nickel reduces nitrogen oxides in the heated combustion tube. Carbon monoxide, formed by reduction of CO2 by nickel, is oxidised by passage through hopcalite at 110°C. Traces of... 

If IR spectrograms do not give any definite info, it is advisable to det C and H contents by micro combustion method and also to det N content by micro-Dumas combustion method... 

METHOD 86 - DETERMINATION OF 1 - 50% ORGANIC NITROGEN IN POLYMERS. MICRO DUMAS COMBUSTION PROCEDURE. 

This Micro Dumas combustion procedure is capable of determining organic nitrogen in amounts down to 1% in a wide range of polymers. 

Analyses. Analyses of ash, carbon, and hydrogen by combustion, and nitrogen by Dumas or micro-Kjeldahl methods (17) were obtained from Schwarzkopf Microanalytical Laboratory, Woodside, N. Y. 11377. 

The uncertainties for the analytical methods are as follows ash by combustion residue, 0.3% absolute C, 0.05 mg C H, 0.3% absolute and N, by Dumas, 5 /A or by micro-Kjeldahl, 1 g (18). The large uncertainties in the measurements of carbon and hydrogen limit the usefulness of data for these elements for very small samples. 

Simek and Tesafik [78] used GC to determine the optimum conditions for elemental analysis. They improved the accuracy of the Dumas micro-method by slowing down the combustion of samples and gradually increasing the oxidation temperature. 

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