表面增强拉曼光谱法测定饮料中4-甲基咪唑和2-甲基咪唑

Determination of 4-Methylimidazole and 2-Methylimidazole in Drinks by Surface-enhanced Raman Spectroscopy

以金纳米粒子为拉曼活性基底,采用便携式拉曼仪进行分析,建立了饮料中4-甲基咪唑（4-Me I）和2-甲基咪唑（2-Me I）的表面增强拉曼光谱分析法,并对检测条件进行优化。在最优条件下（Na_2SO_4溶液为团聚剂,金纳米粒子用量分别为250和200μL）,4-Me I和2-Me I的线性范围分别是0.05~5.00 mg/L和1.0~20.0 mg/L,检出限分别为1.70μg/L和0.21 mg/L;将本法应用于含焦糖色素饮料中4-Me I和2-Me I的检测,4-Me I含量在0.093~0.110 mg/L之间,2-Me I无检出。回收率分别为80.2%~82.7%和78.1%~93.5%,相对标准偏差均小于7.1%。本方法简单、快速、准确,为含焦糖色素饮料中4-Me I和2-Me I的快速检测提供了新方法。

A method was developed for the determination of 4-methylimidazole （4-MeI） and 2-methylimidazole （2-MeI） in drinks by surface-enhanced Raman spectroscopy with Au nanoparticle as substrate, and the detection conditions were optimized. Under the optimum conditions, by using sodium sulfate aqueous solution as agglomeration solution, and 250 or 200 μL of Au nanoparticle as substrate, the linear ranges of 4-MeI and 2-MeI were 0.05- 5.00 mg/L and 1.0- 20.0 mg/L with detection limits of 1.70 μg/L and 0. 210 mg/L, respectively. While applied in the determination of 4-MeI and 2-MeI in drink with lift caramel, the concentration of 4-MeI was determined to be 0. 093-0. 110 mg/L and 2-MeI was not detected. The average recoveries of 4-MeI and 2-MeI were in the range of 80.2% -82.7% and 78. 1% - 93.5% with relative standard deviations 〈7.1%. Above all, this method was turned out to be simple, rapid and sensitive, providing a new method for rapid analysis of 4-Mel and 2-MeI in drink with lift caramel.