Abstract:The present paper proposed for the first time the flocculation-filtration method for separation of interfering substances in milk, such as fat. In this method only two steps were carried out. Firstly, aluminum chloride (PAC, Al2(OH)nCl6-n) is used to flocculate the milk; Secondly, water filter was used to filter the mixture. Then the clear filtrate could be used for the detection of melamine. The whole preprocessing would not take more than one minute. The pretreatment process was optimized. Experiments show that the adding proportion of PAC should be about 2%~3% for best filtration efficiency, and that it would have the best flocculation effect when the mixture was mildly alkaline. High performance liquid chromatography experiments show that the melamine recovery of this method is more than 90%. Samples pretreated by the flocculation-filtration method were clearer and the baselines of spectral curve obtained by sensitizing Raman method were more smooth which means better purification compared to those samples pretreated by centrifugal pretreatment method. The pretreatment method proposed can be used in HPLC and Raman spectroscopy methods for rapid detecting melamine in liquid milk. This method shows better separation effect, simpler operation, and lower time and money cost than those pretreatment processes in the existing standard melamine detection method for milk. By use of this pretreatment method, the melamine rapid detection efficiency would be greatly improved.
刘 峰1,邹明强1*,张 朦1,2,张孝芳1,李 勐1 . 液态乳三聚氰胺液相色谱和拉曼光谱检测快速前处理方法 [J]. 光谱学与光谱分析, 2014, 34(03): 685-688.
LIU Feng1, ZOU Ming-qiang1*, ZHANG Meng1,2, ZHANG Xiao-fang1, LI Meng1 . Study of Fast Pretreatment Method in Detection of Melamine in Liquid Milk Using Liquid Chromatography and Raman Spectroscopy. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(03): 685-688.
[1] General Administration of Quality Supervision, Inspection and Quarantine of the People’s Rupublic of China(国家质量监督检验检疫总局). The Examination of Licensing Criteria for Enterprises Producing Milk Products (2010 Version)(企业生产乳制品许可条件审查细则2010版),2010. [2] The Ministry of Health of the People’s Republic of China(卫生部). Announcement of the Safety Level for Melamine in the Food(三聚氰胺在食品中的限量值的公告). 2011. [3] Muniz-Valencia R, Ceballos-Magana S G, Rosales-Martinez D, et al. Anal. Bioanal. Chem., 2008, 392: 523. [4] Varelis P, Jeskelis R, Food Addit. Contam., 2008, 25: 1208. [5] Ana Mary Rodriguez Mondal, Aurélien Desmarchelier, Erik Koninqs, et al. J. Agric. Food Chem., 2010, 58(22): 11574. [6] Broszat M, Brmer R, Spangenberg B, et al. Journal of Planar Chromatography, 2008, 21: 469. [7] Garber Eric A E. J. Food Prot., 2008, 3: 590. [8] Tang H, Ng K, Chui S S, et al. Anal. Chem., 2009, 81: 3676. [9] Yang S, Ding J, Zheng J, et. al. Anal. Chem., 2009, 81: 2426. [10] Zhang Xiaofang, Zou Mingqiang, Qi Xiaohua, et al. J. Raman Spec., 2010, 41(12): 1655. [11] GB/T22388—2008,National Standard of the People’s Republic of China(中华人民共和国国家标准),2008. [12] GB/T22400—2008,National Standard of the People’s Republic of China(中华人民共和国国家标准),2008. [13] SN/T2805—2011,Entry-Exit Inspection and Quarantine Industry Standard of the People’s Republic of China(中华人民共和国出入境检验检疫行业标准),2011. [14] WEI Na,FENG Xu-qiao, ZHANG Xiao-fang, et al(韦 娜,冯叙桥,张孝芳,等). Spectroscopy and Spectral Analysis(光谱学与光谱分析),2013, 33(3): 697. [15] ZHAO Xiao-fei, WANG Yu-chan, LIU Li-xin, et al(赵晓非,王玉婵,刘立新,等). Chemistry & Bioengineering(化学与生物工程),2008, 25(3): 19.