Analyzer for organic carbon and nitrogen in soil and plants

Abstract

The invention discloses an elemental analyzer for testing organic carbon and nitrogen in soil and plants. The operation method of the elemental analyzer comprises the following steps that plant and soil samples are purified through an automatic sample injector, and then are fed into a combustion reactor along with oxygen, a small amount of pure oxygen is fed into an oxidation furnace to promote samples combustion, the samples after combustion convert into various oxides of carbon and nitrogen and water vapor, the carbon and nitrogen oxides and water vapor are fed into a reduction furnace and the carbon and nitrogen oxides are reduced to detectable gas of CO2 and N2, the detectable gas is dehydrated through an electron sink and then is separated by a chromatographic column, and the separated gas is introduced into a gas isotope mass spectrometer by an open shunt port and then is detected. The elemental analyzer disclosed by the invention realizes the analysis and measurement of isotope abundance of organic carbon and nitrogen in soil and plants, improves analytical precision, effectively guarantees the repeatability, reduces material consumption, reduces consumable replacement frequency thereby improving the efficiency of detection, and has precise gas circuit control and convenient leakage detection functions so that the control precision and reliability of the instrument is improved. Moreover, the elemental analyzer uses oxygen as the purge gas instead of helium so that helium consumption is reduced and can save both gas and a filler.

Description

technical field [0001] The invention relates to an analyzer for organic carbon and nitrogen elements in soil and plants. Background technique [0002] As a means of biogeochemical cycle research, the study of carbon and nitrogen isotope ratios is of great significance: carbon and nitrogen isotopes record past environmental changes, and the δ of trees 13 C, delta 15 The study of N isotope fractionation has become an indispensable part of understanding the carbon and nitrogen cycle process in the past; the analysis of carbon and nitrogen element content and isotope ratio in plants and soils in the permafrost region of the Qinghai-Tibet Plateau is to reveal the carbon and nitrogen source-sink effects and The research on the carbon and nitrogen cycle of the whole ecosystem provides a basis, and it is necessary to develop an analyzer for organic carbon and nitrogen in the above-mentioned plants and soil. [0003] At present, the FLASH2000 organic element analyzer of Thermo Fish...

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Problems solved by technology

[0003] At present, the FLASH2000 organic element analyzer of Thermo Fisher Scientific is the most widely used in the domestic and foreign markets. There are deficiencies and defects in links such as the decline of oxidation ability caused by the accumulation effect of samples, the massive oxidation of the packing in the reduction tube and the replacement of the packing, the replacement of the adsorption trap after long-term use, the leak detection of the gas circuit, and the testing of high-concentration samples. FLASH2000 can only complete the test of sample carbon and nitrogen content. To analyze the sample carbon and nitrogen isotope ratio at the same time, in addition to the online connection with the isotope mass spectrometer, a continuous flow device is also required.

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