Analytical System Based on Raman Spectroscopy in Melamine Detection

People have paid close attention to melamine by Sanlu Event. Melamine, a widely used as an organic chemical in industry, was added in milk to increase the protein content. Obviously, traditional kjeldahl hasn´t suitable to detect real protein content. Focusing on the milk with melamine in market, a rapid and easy method is necessary to meet the needs to detect melamine from the milk. In this study, the analytical system was developed by surface enhanced Raman spectrum (SERS) and portable Raman spectrometer, which had fast detecting and alarming functions. Firstly, Qualitative analysis method for detecting melamine in milk was found. And the peak 709 cm^-1 was used as the essential peak for qualitative analysis method. On the basis of that, quantitative method was further defined. The concentration of melamine in milk vs Ratio of 709 cm^-1/1026 cm^-1 showed a good linear relationship when the standard concentration of melamine in milk within 3 ppm to 10 ppm. Detective limit of this method was lppm, and the quantization limit was 3 ppm. Recovery was in 86% to 106% and satisfied the request of GB/T22388-2008 (80%-110%). Analytical system was established for determination melamine in milk. Multiple functions were contained in this system. Detecting and result were completed rapidly by used analytical system on condition that the concentration of melamine within 3 ppm to 10 ppm. The red signal was displaying at concentration above 3 ppm, and the green signal was giving at concentration below 3 ppm. In a word, the application of this analytical system has an important significance in false protein identification, milk safety control and people health protection.