Whole-course acquisition method of dissolved inorganic carbon content and carbon isotope value of environmental water body

Abstract

The invention provides a whole-course acquisition method of dissolved inorganic carbon content and carbon isotope value of an environmental water body. By using a saturated ammonium dihydrogen phosphate solution (blended when used), the problems of inconvenience during using process of phosphoric acid and the long reaction time are solved. In the laboratory, high-purity helium (99.999%) is used toclean the residual CO2 in the 12mL headspace bottle. A saturated ammonium dihydrogen phosphate solution can be injected in the laboratory in advance, or the saturated ammonium dihydrogen phosphate solution can be injected in the field. Meanwhile, the environmental water body can be firstly injected in the field, and saturated ammonium dihydrogen phosphate is then injected. Thereby, the operationis flexible and convenient. The quality control of the DIC content and isotope determination of the environmental water sample from the field sample treatment to the laboratory measurement process isrealized, and the true representation of the DIC content and the isotope data of the field water body can be ensured to the greatest extent. The method of the invention has great prominent effect on the research of the influence of global carbon cycle and human activity on water body pollution.

Description

technical field [0001] The invention relates to the field of detection of dissolved inorganic carbon in water bodies, in particular to a method for acquiring dissolved inorganic carbon content and carbon isotope values ​​in environmental water throughout the whole process. Background technique [0002] Dissolved Inorganic Carbon (DIC) in water exists in the form of dissolved CO 2 、H 2 CO 3 、HCO 3 - and CO 3 2- etc., the content of each existing form is controlled by the pH value of the water body. DIC of water body comes from atmospheric / soil CO absorbed by rock weathering process 2 As well as carbonate rock minerals, they play an important role in the study of the global carbon cycle. [0003] δ 13 The C-DIC value is widely used in the study of the source of DIC in water bodies and the mechanism of migration and transformation. Currently, the commonly used δ 13 The C-DIC measurement method is a multi-purpose gas preparation device + stable isotope mass spectromete...

AI Technical Summary

Problems solved by technology

However, the predecessors did not further study the effect of the field headspace method, and there is a lack of systematic verification work

[0026](2) Disadvantages of phosphoric acid method

[0028]① Anhydrous solid phosphoric acid has poor operability and is easy to block the needle

[0031]Usually, after the water sample taken from the field reacts with phosphoric acid, it takes 18 hours at room temperature to completely convert the DIC in the water sample into CO2 , cannot be tested immediately

Even if the reaction is completed in the field and transported back to the laboratory for testing, a reaction time of 18 hours is required, otherwise the measured carbon isotope value cannot fully represent the DIC carbon isotope value of the environmental water body

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