Analytical method and apparatus for the determination of total nitrogen contents in aqueous systems

An analytical apparatus for the determination of the total nitrogen content in an aqueous system comprising:

• a decomposition tube packed with a decomposition catalyst;
• a supply means for introducing an inert carrier gas into the inlet of the decomposition tube;
• an injection means for introducing the sample to be analyzed into the decomposition tube;
• a heating means for maintaining the decomposition tube at a temperature of 700.degree. to 1200.degree. C.;
• a condenser means for condensing and removing water from the gaseous mixture produced in the decomposition tube, said condenser means being disposed downstream from the outlet of the decomposition tube;
• a moisture-absorbing tube packed with a moisture absorber which is disposed downstream from the outlet of the condenser means;
• a lower temperature reaction tube packed with an oxidizing agent and/or a reducing agent, and disposed downstream from the outlet of the moisture-absorbing tube;
• a heating means for maintaining the lower temperature reaction tube at a temperature of 300.degree. to 700.degree. C.;
• a carbon dioxide-absorbing tube packed with a carbon dioxide absorber and disposed downstream from the outlet of the lower temperature reaction tube;
• a mass spectrometer disposed downstream from the outlet of the carbon dioxide-absorbing tube;
• a data processing means for determining the total nitrogen content of the sample from mass spectrographic data derived from the mass spectrometer;
• and
• conduit means for providing a connection between the decomposition tube, the condenser means, the moisture absorbing tube, the lower temperature reaction tube, the carbon dioxide-absorbing tube and the mass spectrometer.