Laser Raman spectroscopy method for quickly analyzing content of melamine in milk powder

Abstract

The invention discloses a laser Raman spectroscopy method for quickly analyzing the content of melamine in milk powder, which is carried out according to the following steps of: (1) weighing 1.0 to 2.0g of milk powder, adding 3 to 5ml of acetonitrile, oscillating, ultrasonically processing and standing, then accurately weighing supernatant, adding a protein precipitation agent to the supernatant, evenly mixing and centrifuging the mixture, accurately weighing the supernatant once more, adding n-hexane, oscillating the mixture, and obtaining subnatant which is used as the solution to be detected; (2) successively adding a surface strengthening reagent, the solution to be detected and an inorganic salt flocculant to a detection pond, evenly shaking the mixture, putting the detection pond in a laser Raman spectrograph detection room, and carrying out Raman spectrum scan in 400 to 1700 cm<-1> range to obtain a Raman spectrogram; (3) carrying out qualitative judgment; and (4) carrying out quantitative calculation. The pretreatment procedure of the measurement method of the invention is simple and quick, the recovery rate of the melamine is high, the technical problem that the treatment method of the milk powder in the prior art is not suitable for Raman spectroscopy detection is overcome, and the method is the important supplement of the traditional detection technology.

Description

technical field [0001] The invention relates to a detection method, in particular to a laser Raman spectrum detection method for quickly analyzing the content of melamine in milk powder. Background technique [0002] The melamine milk powder incident in 2008 once again sounded the alarm on food safety. Mixing melamine in raw milk can increase the nitrogen content of raw milk. In the determination of the protein content of dairy products in my country, the Kjeldahl method is still used to determine the protein content through the nitrogen content in dairy products. This gives criminals an opportunity to increase the nitrogen content of raw milk by adding nitrogen-containing cheap industrial raw materials, so that the test results show the illusion of falsely high protein content. Long-term intake of melamine can cause reproductive and urinary system damage, leading to bladder and kidney stones. [0003] Although the state approved the release of the national standard of "Ra...

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Problems solved by technology

Among them, the Chinese patent with the application number 200810225085.8 "Raman spectroscopy and kit for on-site rapid detection of melamine in liquid milk" uses Raman spectroscopy to detect melamine, which is easy to operate, sensitive and accurate, and has good reproducibility. but only for liquid milk

For milk powder, its composition is complicated, and the method of the above patent is used for processing, and the recovery rate of melamine is low, which cannot meet the detection requirements; the pretreatment steps of milk powder in the prior art are cumbersome, and are not suitable for the detection of Raman spectrometer

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