衍生化/表面增强拉曼光谱快速检测乳制品中亚硝酸盐

Rapid determination of nitrite in dairy products by derivatization/surfaceenhanced Raman spectroscopy

目的基于衍生化-表面增强拉曼光谱技术,开展奶粉中亚硝酸盐快速定量分析方法的研究,建立一种简单、快速、灵敏的奶粉中亚硝酸盐的检测方法。方法采用重氮化-偶合反应,以金纳米粒子为增强试剂,将弱拉曼活性的亚硝酸根衍生成具有强拉曼活性的偶氮染料,通过对偶氮染料的测定实现对奶粉中亚硝酸盐的间接检测,优化了衍生化、前处理及检测条件。结果在优化条件下,方法的线性范围为0.030-1.0 mg/L、RSD小于14.8%、检出限为0.014 mg/L。方法用于奶粉样品分析的回收率为99.6%-128.9%、RSD为4.6%-15.8%。结论该方法简单快速、准确可靠,适用于乳制品中亚硝酸盐的分析检测。

Objective To establish a method for the rapid determination of nitrite in milk powder based on derivatization/surface-enhanced Raman spectroscopy technique.Methods Nitrite was transformed into an azo dye by diazotization-coupling reaction,which has a strong SERS response with Au nanoparticles as substrates.Therefore the concentration of nitrite could be indirectly determined by detecting the SERS signals of the azo dye.The conditions of derivatization,pretreatment and detection were optimized.Results The linear range of nitrite was0.030-1.0 mg/L,the LOD was 0.014 mg/L and RSD was below 14.8%.The method was applied to the analysis of nitrite in milk powder with the recovery of 99.6%-128.9%and the RSD of 4.6%-15.8%.Conclusion The result showed that this method is a simple,rapid,and selective analytical method at a good accuracy and precision.It has a great potential in quality monitoring of dairy products.