Dumas nitrogen/protein analyser, D50/D200

Determines the nitrogen/protein content of samples by combustion, purification, reduction and thermal conductivity detection. A single sample is analysed in 4 minutes without pretreatment; the reaction is non-toxic and harmless, for safe and environmentally friendly operation.

• Fast cooling: the instrument reaches shutdown temperature in 30 minutes
• Core pneumatic components by SMC® and mass flow controllers by Bronkhorst® for long-term reliability
• Two-stage combustion and oxidation: pure-oxygen combustion in the primary combustion tube pre-oxidises and digests the sample; the remainder passes with the carrier gas through the secondary combustion tube and is completely digested after oxidation over a mixture of Pt catalyst and copper oxide
• Three-stage water removal: an electronic condenser removes most of the water so that the desiccant can work; primary and secondary drying tubes remove the traces
• Efficient reduction: the reducing agent reduces nitrogen oxides to nitrogen gas and absorbs excess oxygen
• Thermal conductivity detector (TCD) determines the nitrogen produced by reduction
• Applications: total nitrogen in diesel exhaust fluid, cereals, seeds, meat and meat products, animal feed, dairy products, red wine, fertilisers and soil
• AOAC: standard method for crude protein in grains and oilseeds, meat/meat products and animal feed
• ISO: quality assessment of cereals, pulses, ground cereal products, oilseeds and animal feed
• AACC and ICC: protein content of grain
• ISO and DIN: evaluation of dairy products
• AOAC and ISO/DIN: standard method for total nitrogen in fertilisers and soils
• ISO (2015): nitrogen content of natural raw rubber and natural latex
• Sampling: 1-disc 120-position autosampler (D200 only) for direct analysis of large numbers of samples
• SMC® pneumatic components rated for 100,000 sample injections, with low maintenance costs
• Contactless in-situ detection by anti-interference infrared modules: if the sampling disc is occupied, the self-test is interrupted and a message is shown to prevent maloperation (D200 only)
• Samples (solid or liquid) can be added during preparation without stopping the automatic analysis
• Combustion furnace: high temperature, pure oxygen and two-stage combustion ensure thorough oxidation and digestion
• Metal condenser and two-stage desiccants remove water completely; the desiccants can be reused 2,000 times
• New consumables reduce nitrogen oxides, absorb excess oxygen and extend service life; combustion and reduction tubes can be reused 1,000 times
• Pneumatic system: a two-stage regulator isolates the detector system from external pressure fluctuations and combustion-induced pressure changes, ensuring stability