Method for measuring total nitrogen content in liquid

Abstract

The invention provides a method for measuring total nitrogen content in liquid, which includes the following steps: providing a to-be-measured liquid nitrogenous sample; adding potassium persulfate in the to-be-measured sample to obtain a mixed solution under the heating condition; sequentially performing ultraviolet catalysis and high-temperature heating to the mixed solution, so as to obtain a digestion product; detecting the digestion product to obtain ultraviolet spectrum data; and obtaining the total nitrogen content in the liquid as per the ultraviolet spectrum data and a predetermined standard curve. Through the adoption of the method provided by the invention, the digestion of the nitrogenous ingredient in the liquid sample is more complete, the digestion effect is better, the digestion of the nitrogenous ingredient as well as the digestion of the reductive ingredient in the to-be-measured sample can be realized, the reductive function of the to-be-measured sample is lost, the interference in the total nitrogen content measurement is reduced, so that the uniformness of the digestion effect is improved, the recovery rate of the total nitrogen measurement is improved, and the accuracy of the measurement result is improved.

Description

technical field [0001] The invention relates to the technical field of nitrogen analysis and determination, in particular to a method for determining the total nitrogen content in a liquid. Background technique [0002] Total nitrogen includes inorganic nitrogen such as nitrate, nitrite and ammonia salt and organic nitrogen such as protein, amino acid, ribonucleic acid, enzyme and organic amine. For living organisms, nitrogen is an essential element to maintain vital signs. It is a component of structural units such as protein and ribonucleic acid in organisms, and is the basis of life activities. Nitrogen nutrition directly or indirectly affects the metabolism, growth and development of organisms in many ways, and is of great significance to the life activities of organisms. In order to maintain the metabolic balance of nitrogen in the body and maintain the vital signs of the organism, it is necessary to continuously ingest nitrogen-like nutrients from the outside world, s...

AI Technical Summary

Problems solved by technology

[0004] High-pressure digestion has a good digestion effect on inorganic nitrogen in nitrogen-containing compounds, but for protein nitrogen such as water-soluble proteins, such as water-soluble cowhide collagen, due to its complex structure, there are incomplete digestion and incomplete digestion when high-pressure digestion is used. Thorough phenomenon, thus affecting the determination of total nitrogen content, resulting in low recovery rate of total nitrogen determination and inaccurate determination results

For liquid samples, especially liquid-like nutrients, most of the protein nitrogen is water-soluble, and it also contains reducing components, such as sugars, which will react with oxidants, thereby affecting the nitrogen-containing group. When the total nitrogen content is measured by the above method, the digestion product obtained is not complete and thorough, resulting in inaccurate measurement results.

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