表面增强拉曼光谱法同时检测奶粉中三聚氰胺和二聚氰胺

本文建立了奶粉中同时检测三聚氰胺及二聚氰胺的表面增强拉曼光谱法.奶粉样品经15％三氯乙酸溶液提取,中性氧化铝吸附杂质后进行拉曼光谱检测.三聚氰胺线性范围为0.0050～0.075 mg/L,检出限为0.0015 mg/L,回收率在79.5％～124％之间,相对标准偏差小于8.8％(n=5);二聚氰胺线性范围为0.50～l0mg/L,检出限为0.15 mg/L,回收率在76.5％～112％之间,相对标准偏差小于9.4％(n=5).该方法相比常规表面增强拉曼光谱法,仅通过一种样品前处理手段即可对奶粉中的三聚氰胺或二聚氰胺进行定性检出及定量分析,相比色谱等检测方法具有样品前处理过程简单、耗时短等优点,在奶粉质量监控方面具有良好的应用前景.

Simultaneous Determination of Melamine and Dicyandiamide in Milk Powder by Using Surface-enhanced Raman Spectroscopy

A new analytical method was developed for the simultaneous determination of melamine and dicyandiamide in milk powder by surface-enhanced Raman spectroscopy(SERS).The sample was extracted by 15 ％ trichloroacetic acid,and the impurities were adsorbed by neutral Al2 O3 before Raman detection.The linear range for melamine was from 0.0050 to 0.075 mg/L,and the limit of detection was 0.0015 mg/L.While the method was applied to the analysis of melamine in milk powder,the recoveries were in the range of 79.5％-124％ with the relative standard deviation lower than 8.8％.The linear range for dicyandiamide was from 0.50 to 10 mg/L,and the limit of detection was 0.15 mg/L.For the analysis of dicyandiamide in milk powder,the recoveries were in the range of 76.5％-112％,and the relative standard deviation was lower than 9.4％.Compared with normal surface-enhanced Raman spectroscopy methods,this analytical method can detect or quantify melamine and dicyandiamide in milk powder.The method also has the advantages of simple pre treatment process and short time-consuming compared with chromatography and other analytical methods,showing great potential in quality monitoring of milk powder.