1. Determination of Total Nitrogen Dumas Combustion Method

2. Principle Heating the sample at T > 850 °C + O 2 Mineral and organic nitrogen compounds are oxidized and/or volatilized. The combustion products are oxides of nitrogen (NO x ) and molecular nitrogen. After transforming all nitrogen into molecular nitrogen, the content of the nitrogen gas is measured using e.g. thermal conductivity

3. Comments „Total-N“ better: Dumas-N (GB) Term: „air drying < 40°C “ as the method of choice (FIN, AFNOR, AUST) Losses of ammonia in liquid samples (sludges) after drying (FR, GB), use of moist samples ? Description of microwave pretreatment (AFNOR)

4. Comments Detector: „at least 850°C“ (NE) Detector: „thermal conductivity or other device specific detectors“ (AUST) Reference compounds: „EDTA or other certified reference materials“ (AUST) Burning assistance substances – deleted Results: in % and mg/g (DIN)

5. Method variations Precision data: soil / biowaste: Milling quality: SO13 ; < 2mm0,32 % NS = 0,03 % NS rel = 9 SO13 ; < 250 μm0,33 % NS = 0,01 % NS rel = 3 CW KAS3 ; < 2mm 1,86 % NS = 0,07 % NS rel = 4 CW KAS3 ; < 250 μm 1,78 % NS = 0,01 % NS rel = 1