High-performance liquid chromatography method for measuring nucleotide in milk powder

Abstract

The invention relates to a high-performance liquid chromatography method for measuring nucleotide in milk powder, and belongs to the technical field of detection for food additives. The method comprises the following steps of: preparing a contrast solution by using a nucleotide standard substance; weighing a test sample, dissolving the test sample in distilled water through ultrasonic oscillation, so that the nucleotide in the milk powder is dissolved in the distilled water; adjusting the pH value of the test sample solution by hydrogen nitrate until the pH value is 3 to 4, precipitating proteins, filtering and removing the proteins, fixing the volume of a filtrate by using water to obtain a to-be-tested solution; measuring nucleotide chromatographic peak areas in the test solution and the contrast solution by high performance liquid chromatography; and calculating the nucleotide content in the test sample by an external standard method according to the concentration of the nucleotide in the contrast solution, the nucleotide chromatographic peak area in the test solution and the mass of the test sample. The method is simple, convenient to operate and high in precision; proteins can be completely separated, so that interference with the measurement for the nucleotide is eliminated; and a good condition is supplied to measurement of the nucleotide in the test sample.

Description

Technical field [0001] The invention relates to a method for determining nucleotides in milk powder by high performance liquid chromatography, which belongs to the technical field of food additive detection. Background technique [0002] Nucleotide is a nutrient that plays an important role in the growth and development of infants and young children, so nucleotides can be used as dairy additives. However, the human body's demand for nucleotides is limited, and the more the better, the content of nucleotides in dairy must be controlled. In the milk powder standards of dairy product manufacturers, the content of nucleotides is listed as an important indicator. Therefore, it is extremely important to control the content of nucleotides in dairy products, which requires corresponding technical support. The detection methods currently reported mainly include microbiological method, capillary electrophoresis, high performance liquid chromatography, etc. Among them, HPLC has fast analy...

AI Technical Summary

Problems solved by technology

According to related data, when processing samples, it is generally used to add a certain amount of acetic acid or perchloric acid to the sample solution to precipitate the protein, and then separate and remove it. This method has been proved by many tests to be unsatisfactory.

Add acetic acid or perchloric acid to the sample solution to precipitate protein, but the protein precipitate is viscous, the solution layering is unclear, and an emulsified layer appears, which is difficult to filter and wash, which seriously affects the determination of nucleotides by high performance liquid chromatography. The separation method not only interferes with the separation of chromatographic peaks in nucleotide components, but also seriously affects the accuracy of nucleotide determination

Images