荧光光谱法水相测定乳制品中三聚氰胺

Determination of melamine in dairy by spectrofluorometric method in water phase

目的：建立一种荧光光谱法水相测定三聚氰胺的新方法 应用酸效应对型体分布的影响,研究了反应机理。方法：在水介质中,三聚氰胺与荧光素钠缔合,使体系的荧光强度增强,从而建立三聚氰胺的测定新方法。结果：在实验最适条件下,在4.8×10^-3-90μg/m l、1.6×10^-2-280μg/m l范围内,体系荧光强度改变值（ΔF）与三聚氰胺的浓度分别呈现良好的线性关系,线性回归方程分别为ΔF=2660.3ρ＋36.67（r=0.9992）、ΔF=768.92ρ＋160.66（r=0.9996）,检出限分别为1.4、5 ng/m l。样品加标回收率为95.7%-110.0%,RSD小于0.47%。结论：方法灵敏度高、精密度好、操作简便、费用低,用于乳制品中三聚氰胺的测定,结果满意。

Objective：To set up a novel spectrofluorometric method for the determination of melamine in water phase and study the reaction mechanism applying the influence of the acid effect on the species distribution.Methods：In water phase,melamine and fluorescein sodium formed the ion-association complex which resulted in the enhancement of fluorescence intensity.Based on this phenomenon,we had established a new method for the determination of trace melamine.Results：Under the optimum experimental conditions,it was found that the enhanced intensity was propotional to the concentration of melamine in the range of 4.8×10^-3～90 μg/ml and 1.6×10^-2～280 μg/ml,respectively.Linear regression equation was ΔF=2660.3ρ＋36.67（r=0.9992）,ΔF=768.92ρ＋ 160.66（r=0.9996）with the detection limits of 1.4,5.0 ng/ml,respectively.The average recoveries were 95.7%～110.0% with relative standard deviation（RSD） lower than 0.47%.Conclusion：The method has the advantage of simplicity,high sensitivity,and has been applied to the determination of melamine in dairy sample to obtain satisfactory results.