基于多巴胺共振散射光谱法测定牛奶中的三聚氰胺

Determination of Melamine based on Dopamine Resonance Scattering Spectral Method

在氢氧化钠介质中,氯金酸与多巴胺发生氧化还原反应生成金纳米粒子而使体系在519. 4 nm处产生一个较强的共振散射峰。当加入三聚氰胺时,多巴胺和三聚氰胺通过氢键结合并形成稳定的多氢键化合物,使得结合的多巴胺还原能力降低而不能还原氯金酸,阻碍金纳米粒子的形成,导致体系519. 4 nm处的共振散射峰强度降低。据此建立了检测三聚氰胺的共振散射光谱法。在优化的实验条件下,c(三聚氰胺)在8. 33×10-7~1. 67×10-5mol/L范围内与该共振散射峰强度的降低值(ΔI519. 4 nm)呈良好线性关系,其相关系数为0. 996 1,检出限为2. 1×10-7mol/L。将该共振散射光谱法用于牛奶制品中的三聚氰胺的测定,回收率为96. 0%~108. 0%,相对标准偏差为1. 3%~2. 7%。

In Na OH solution,gold nanoparticles that exhibited a strong resonance scattering peak at 519. 4 nm were prepared via redox reaction between HAu Cl4 and dopamine.When the melamine was added,dopamine interacted with melamine and formed a stable complex by hydrogen bonds,HAu Cl4 could not be easily reduced by the interacted dopamine,and the formation of gold nanoparticles was interrupted,resulting in the decrease of resonance scattering intensity.Based on this,a resonance scattering spectral method was developed for the determination of melamine.Under the optimal conditions,the decreased resonance scattering intensity( ΔI519. 4 nm) was linear to c( melamine) in the range of 8. 33×10^-7~ 1. 67×10^-5 mol/L,with a correlation coefficient of 0. 996 1 and a detection limit of 2. 1×10^-7 mol/L.This method was utilized to detect melamine in pretreated liquid milk products,with the recoveries of 96. 0% ~ 108. 0% and relative standard deviations of 1. 3% ~ 2. 7%.