三聚氰胺-Cu^(2+)-ANS三元络合物荧光光谱法检测超痕量三聚氰胺

Determination of Ultratrace Melamine by Fluorescence Spectroscopy Using Melamine-Cu^(2+)-ANS Ternary Complex

利用荧光光谱法研究了三聚氰胺(MEL)和Cu2+与8-苯胺-1-萘磺酸(ANS)的相互作用。研究表明,MEL和Cu2+均对ANS有荧光猝灭作用,且猝灭机理均为静态猝灭。计算了表观结合常数和结合位点数。Cu2+的引入使得MEL猝灭ANS荧光的效果急剧增强,体系的相对荧光峰强与MEL浓度(1×10-10～1×10-5mol/L)的对数值呈良好的线性关系,三聚氰胺的检出限为3.8×10-11mol/L。紫外、荧光、三维荧光光谱的结果表明,MEL及Cu2+对ANS的荧光猝灭为协同作用,三者形成了三元络合物。本研究建立了荧光光谱检测超痕量三聚氰胺的新方法,为奶粉、乳制品中三聚氰胺的检测提供了新思路。

The interactions between melamine（MEL） and copper ion（Cu^2＋） with 8-anilin-1-naphthalene sulfonic acid（ANS） were investigated by fluorescence spectroscopy. The results indicated that both MEL and Cu^2＋ could quench the fluorescence of ANS by the static quenching style. The binding constants and site number were obtained. The fluorescence of ANS was dramatically quenched by MEL when Cu^2＋ solution was added. A good linear relation between relative fluorescence intensity and logarithm concentration of MEL was found in the range of 1×10^-10-1×10^-5 mol/L with a detection limit of 3.8×10^-11 mol/L. The results from UV,2D and 3D fluorescence demonstrated the cooperative quenching of the ANS fluorescence by MEL and Cu^2＋ via Mel-Cu^2＋-ANS ternary complex. In this study,a novel detection approach of MEL based on fluorescence spectroscopy was established. The investigation provided a new research trend in melamine testing in milk and dairy products.