Method for measuring nonprotein nitrogen content in plants and plant products

Abstract

The invention provides a method for measuring nonprotein nitrogen content in plants and plant products, which includes the following steps: separating protein nitrogen from a plant and a plant product to obtain a to-be-measured sample containing nonprotein nitrogen; adding potassium persulfate into the to-be-measured sample to obtain a mixed solution under the heating condition; performing ultraviolet catalysis and high-temperature heating to the mixed solution sequentially, so as to obtain a digestion product; detecting the digestion product to obtain ultraviolet spectrum data; and obtaining the nonprotein nitrogen content in the plant and the plant product as per the ultraviolet spectrum data and a predetermined standard curve. The method provided by the invention has excellent digestion effect, the digestion of the nonprotein nitrogen 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 nonprotein nitrogen ingredient digestion is reduced, so that the digestion effect becomes more uniform, the recovery rate of the nonprotein 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 content of non-protein nitrogen in plants and plant products. Background technique [0002] Nitrogen is an indispensable nutrient element for plant growth and development, known as the element of life, and nitrogen metabolism plays a dominant role in plant metabolism. Nitrogen in plants can be divided into protein nitrogen and non-protein nitrogen. Protein nitrogen is the nitrogen content that plants are using; non-protein nitrogen mainly includes amino acids, alkaloids, nitrates, nitrites and ammonia salts, etc., which is a storage form nitrogen; total nitrogen represents the total nitrogen uptake by plants. The content of nitrogen in plants changes with its physiological status and environmental conditions, so measuring the content of different forms of nitrogen is very important for studying the nitrogen absorption, tra...

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Problems solved by technology

[0004] High-pressure digestion is better for inorganic nitrogen in non-protein nitrogen, but for plant alkaloids and amino acid non-protein nitrogen, such as nicotine, theophylline, leucine, etc., due to its complex structure, high-pressure digestion is used Sometimes there is incomplete and incomplete digestion, which leads to low recovery rate of non-protein nitrogen determination and inaccurate measurement results

Especially for plants and plant products, most of their non-protein nitrogen belongs to plant alkaloids or amino acids, and plants and plant products also contain reducing components, such as sugars, and these reducing components will react with oxidants, thereby affecting the The digestion of nitrogen-containing components results in incomplete and incomplete digestion. When the above method is used to measure the non-protein nitrogen content, the digestion products obtained are not complete and thorough, resulting in inaccurate measurement results.

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