Raman spectroscopy method of measuring melamine contents in dairy products having different matrixes

Abstract

A raman spectroscopy method of measuring melamine contents in dairy products having different matrixes. The method includes: (a) establishing a database of characteristic curves of dairy products having different matrixes; (b) taking several copies of the dairy products having one certain unknown matrix and adding melamine standard solutions having different concentrations therein, to obtain a series of dairy product samples in which the relative concentrations of the melamine are known; (c) performing raman spectrum testing analysis and obtaining corresponding characteristic peak intensities to obtain a slope of the characteristic curve showing variation of the characteristic peak intensities with the relative concentrations of the melamine; (d) searching the database of step (a) using the slope of the characteristic curve of the dairy product samples to find a matching characteristic curve, and (e) calculating concentration of melamine in the dairy products by using the matched characteristic curve and the characteristic peak intensity.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of Chinese Patent Application No. 201310155894.7 filed on Apr. 28, 2013 in the State Intellectual Property Office of China, the disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to the field of detecting melamine content in dairy products, and more particularly, to the method of detecting melamine content in dairy products having different matrixes.[0004]2. Description of the Related Art[0005]Chinese government-issued regulations “Method of Detecting Melamine in Raw Milk and Dairy Products” (GB / T 22388-2008), regulate three methods of detecting melamine in raw milk, in dairy products, and in milk contained products, i.e., high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS / MS), as well as gas chromatography-mass spectrometry [including GC-MS, GC-MS / MS]. Although th...

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Benefits of technology

[0009]Concerning the above, one objective of the present invention is to establish a testing and data analyzing method to avoid interferences from the different matrixes in dairy products by using raman spectroscopy, and to achieve the quantitative detection of melamine in the dairy products having different matrixes by using raman spectroscopy.

Problems solved by technology

Although these methods can facilitate accurate qualitative analysis and quantitative analysis, they can only be performed in labs, due to limitations such as complicated operations, harsh operating conditions, high cost of consumptive materials, and low detecting speed, or the like.

If a quantitative calculation is still done with the characteristic curve of the fresh milks, then it would cause large deviation of the calculation results from the real values.

Real measurement indicates that such a method will cause a relatively large measuring deviation upon detecting various liquid milks available on the market.

Therefore, one of main difficulties for quantitative detection of the melamine in dairy products with raman spectroscopy is to remove interferences caused by different matrixes in the dairy products being measured.

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