Multi-element analyzer design principle

Multi-Element Analyzer Design Principles Analyze automated instruments for organic elements. Equipped with microcomputer and microprocessor for condition control and data processing, the method is simple and rapid.

There are four methods for measuring carbon, hydrogen, and nitrogen analyzers:

1 differential thermal conductivity method. Also known as self-integrated thermal conductivity method. The combustion part of the sample was analyzed using carbon, hydrogen, and nitrogen analysis methods for the quantitative analysis of organic elements. When the sample is decomposed, a certain amount of oxygen is introduced to aid combustion, and helium is used as a carrier gas to carry the combustion gas through the combustion tube and the reduction tube. The inside of the second tube is respectively filled with an oxidant and a reduced copper, and the silver wire is filled to remove interferences (e.g., Halogen, etc.) Finally, the gas from the reducing tube (only carbon dioxide, water, and nitrogen except helium) is introduced into a volume of the vessel, mixed, and then carried by the carrier gas into an absorption tube containing magnesium perchlorate. To remove moisture. There is a thermal conductivity cell detector before and after the absorption tube, and the water content is given by the difference between the two response signals. The moisture-removed gas is then passed through a soda absorbing asbestos absorber tube, and the carbon dioxide content is determined from the difference between the signal before and after the absorber tube thermal conductivity cell signal. The last set of thermal conductivity cells measures the difference between the pure helium gas and the nitrogen-containing carrier gas signal and proposes the nitrogen content.

2 reaction gas chromatography. The elemental analyzer is composed of a combustion part and a gas chromatograph. The combustion apparatus is similar to the above. The combustion gas is loaded by helium into a gas chromatography column filled with polystyrene-type polymer beads and separated into nitrogen, carbon dioxide, and water3 The chromatographic peaks were obtained by an integrator and the area of ​​each peak was determined. From the standard samples of known carbon, hydrogen, and nitrogen contents, the conversion factor of the three elements was obtained, and the content of each element of the unknown sample was obtained.

3 electricity method. Also known as coulomb analysis.

4 Conductance method.