Nitrogen extracting and purifying device of nitrogen isotope sample in water

Abstract

The invention relates to a nitrogen extracting and purifying device of a nitrogen isotope sample in water. The nitrogen extracting and purifying device comprises a nitrogen bottle (1), a carbon dioxide absorption cold trap A (2), a carbon dioxide absorption cold trap B (5), a water-vapor absorption cold trap (6) and a U-shaped gas sample collector (8), which are successively connected end to end, wherein the gas outlet end of the U-shaped gas sample collector (8) is communicated with a long needle B (19) through a rubber tube, and the long needle B (19) enters below the liquid level in a gas monitoring cup B (10). The device has the advantages that a tedious chemical treatment process is avoided, and the device is time-saving and labor-saving and simple and efficient; the nitrate, nitrite and solubleness nitrogen in the water are completely converted into pure nitrous oxide gas or pure nitrogen which can be completely collected, so that the isotope fractionation is avoided; the CO2 and water-vapor can be removed, and the interference in testing is avoided; the device can be widely applied to the scientific search and production of colleges, scientific research institutions, industrial and mining enterprises, and the like.

Description

technical field [0001] The invention relates to a nitrogen extraction and purification device for nitrogen isotope samples in water, which is mainly used for stable nitrogen isotopes of nitrate, nitrite and dissolved nitrogen in water ( 15 The pretreatment of N) composition belongs to the field of element and isotope testing in chemistry. Background technique [0002] Nitrate and nitrite in water are difficult pollutants to remove. Excessive nitrate and nitrite content in drinking water can cause poisoning, and long-term drinking is prone to cancer. Finding out the source of nitrate and nitrite in water is an important environmental science issue. Due to the nitrogen stable isotopes of nitrate and nitrite from different sources ( 15 N) composition is different, nitrogen stable isotope ( 15 N) has become an important tool for studying sources of nitrate and nitrite in water. [0003] At present, nitrogen isotope pretreatment in water is a cumbersome and slow process. The...

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Problems solved by technology

Main problems: (1) The enrichment and precipitation of nitrate and nitrite in water requires an ultra-clean environment, which is time-consuming and labor-intensive, and high-quality deionized water must be used in the process; (2) Cationic exchange resin is used for enrichment, There is incomplete ion exchange, which leads to nitrogen isotope fractionation; (3) if the precipitation is not complete, it will also lead to nitrogen isotope fractionation; (4) solid powder is not completely cracked at high temperature in the stable isotope mass spectrometer, and nitrogen isotope fractionation exists

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