The Dumas method, which determines Nitrogen content by combustion and analysis of the evolved N2 gas, began to replace the Kjeldahl method in the late 1980's. The combustion method offered a greater speed of analysis and allowed higher throughput while removing dangerous chemicals from the laboratory.
Development of new instruments using Dumas' combustion method seemed to have stopped, with little improvement to the technique. The Turbo N 4040 has been developed to offer a solution for the 21st Century.
The Turbo N 4040 is the most advanced, efficient, and fastest instrument for Nitrogen / Protein Analysis.It offers low-cost analysis for foodstuffs, feed, soil, grain, polymers, fuel, etc., and is compliant with AOAC, AACC, AOCS, ASTM, ASBC, methods and international norms and regulations.
The sample is weighed into a tin foil and placed into the next available space in the 120 Position Autosampler. Each sample is purged with helium prior to analysis to remove nitrogen contamination from the atmosphere. The sample then drops into the combustion furnace at 1030 °C.
The He carrier gas is switched to pure Oxygen for a specific time determined by the sample weight and matrix, and catalytic combustion of the sample occurs. To ensure complete combustion the gases pass through a patented chemical "oxygen pump". This ensures complete combustion and this, combined with the low flow rate, means that no soot or ash is carried through the system causing plugging and cleaning problems found with other instruments.
The combustion gases travel through the Copper Reduction Reactor where any small amounts of excess Oxygen are removed and any traces of NOX are reduced to Nitrogen. Next, the water must be removed and the Turbo N uses a Nafion® membrane system that removes all of the moisture without any chemical trap. It is far more efficient than any cooling device and is maintenance free.
From here the gases go to the self-regenerating CO2 traps. Carbon Dioxide is absorbed, and after the analysis the trap is heated and the CO2 driven off. Constant changing of hazardous chemicals is not required on the Turbo N.
Electronic Mass Flow Controllers ensure that the flow is completely stable when the gas enters the Thermal Conductivity Cell. The Thermal Conductivity Detector is the most advanced on the market. It is a single filament cell and that means there is no need for a reference flow of helium and requires a much simpler analytical configuration.