Quantum Analytical Services, in an all Africa first, leads the market for protein and nitrogen analysis through the highly efficient Dumatherm instrument aquired from Gerhardt Laboratory Systems, Germany, and taken into production July 2007

The new Dumatherm comprises all advantages of the Dumas- method: It is fast, precise and cost efficient. The clever design of the furnace chamber in combination with the direct analysis of all resulting gases provides the user with results within 2-3 minutes. Thanks to the construction of the instrument, the Dumatherm has hardly any wear- and -tear parts, which reduces costs for service significantly.

Principle of analyses

Solid or liquid samples are combusted at high temperatures in the presence of catalysts into oxides.

With the help of copper, the resulting nitrogen oxides are reduced to elemental nitrogen while the by-products water and carbon dioxide are separated completely. The remaining nitrogen is analyzed using a single filament detector.

Analysis procedure

The samples drops from the autosampler into a purge chamber, which is constantly purged with helium. The combustion is initiated by switching the gas flow to oxygen and the transport into the 1000 °C hot, upright combustion furnace. The ashes are collected in a quartz tube insert, which can be easily taken out and exchanged - even when the unit has reached operating temperature.

Among all resulting combustion products, CO₂, H₂O and N-oxides, the nitrogen oxides react in the reduction furnace to elemental nitrogen. The majority of the water is separated using an intelligent tube membrane system, which works using a semi permeable wall in the counter flow.

Any remaining amounts are caught in an absorption trap, where the separation of CO₂ is done in self-regenerating absorption traps. Elemental nitrogen remains, which is measured in a thermal conductivity detector without any reference gas flow.

Gerhardt Laboratory Systems

Dumatherm technical specification

Jean Baptiste Dumas - Wikipedia