衍生化-富集-表面增强拉曼光谱法快速筛查奶粉中亚硝酸盐

目的 建立衍生化-富集-表面增强拉曼光谱法快速检测奶粉中亚硝酸盐的分析方法。方法 样品水溶液通过除蛋白、衍生化后，采用阳离子小柱PSY-001对衍生化合物进行富集，再使用表面增强拉曼光谱对样品中的亚硝酸盐含量进行定性检测。结果 7类不同奶粉，采用本研究所建立的方法进行检测，根据不同的批处理量，单个样品检测全过程只需3~15 min，定性检测限为0.4 mg/kg，远低于国家安全标准对亚硝酸盐的限量要求(2 mg/kg)。方法的灵敏度在96%～100%，特异性为100%，假阴性率为0%～4%，假阳性率为0%，相对准确度为98%～100%。结论 该方法操作简单、快速，易于掌握，适用于奶粉中亚硝酸盐的快速筛查。

Rapid detection of nitrite in milk powder by derivatization- enrichment-surface enhanced Raman spectroscopy

Objective To eatablish a method for the rapid determination of nitrite in milk powder by derivatization-enrichment-surface enhanced Raman spectroscopy. Methods The aqueous solutions of samples were deproteinized and derivatized, and the derived compounds were enriched by cationic cartridge PSY-01, finally, the nitrite in samples were qualitative detected by surface enhanced Raman spectroscopy. Results Seven kinds of milk powders were tested by this method, which took only 3-15 minutes per sample, depending on batch processing capacity. The limits of detection (LOD) of this method was 0.4 mg/kg and much less than maximum residue limit (MRL) of nitrite specified in national food safety standard of China (2 mg/kg). The sensitivity of this method was 96%-100%, the specificity was 100%, the false negative rate was 0%-4%, the false positive rate was 0%, and the relative accuracy was 98%-100%.