分子印迹-基质固相分散快速分离分析辣椒制品中的苏丹红

Fast separation and analysis of Sudan dyes in chili products by molecular imprinted-matrix solid phase dispersion

以纳米SiO2为载体,苏丹红IV为模版分子,甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,采用表面印迹法制备分子印迹物聚合物。对该聚合物进行了吸附等温线的测定以及Scatchard分析,结果表明分子印迹聚合物对苏丹红IV有两种结合方式,计算得到的最大表观吸附量(Qmax)和平衡离解常数(Kd)分别为:Qmax1=0.8306mg/g,Kd1=4.760mg/L;Qmax2=4.146mg/g,Kd2=112.4mg/L。进行了吸附动力学的测定,结果显示该聚合物对苏丹红IV的吸附符合准二级动力学模型。最后应用该聚合物进行基质固相分散萃取辣椒制品中的苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ,最佳实验条件为:聚合物与样品的用量比1∶1,研磨时间8min,洗脱剂为4mL 5%乙酸乙醇溶液。该方法兼备了分子印迹技术的选择性和基质固相分散技术的快速分离性。

Molecularly imprinted polymer（ MIP） was synthesized by surface imprinting technology using nano SiO2 as supporter, Sudan IV as template, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker.The isothermal absorption experiment and kinetics absorption experiment of MIP were applied.The results of isothermal absorption experiment and Scatchard analysis showed that there were two kinds of binding sites.By calculating ,the values of the apparent maximum absorption capacity Qmax and the dissociation constant Kd were as follows： Qmax1 = 0.8306mg/g, Kd1 =4.760mg/L, Qmax2 =4.146mg/g, Kd2 = 112.4mg/LThe results of kinetics absorption experiment revealed that the absorption of MMIP for Sudan IV was conforming to pseudo-second order absorption model.The prepared MIP was used as the sorbent of matrix solid phase dispersion to analyze the Sudan I, II, III and IV in the chili powder.The experimental conditions were optimized：the ratio of MMIP and sample was 1：1 ,milling time was 8min,and the eluent was 4mL of 5% acidified ethanol.This method possesses was not only the high selectivity of molecularly imprinting technology, but also the fast separation of matrix solid phase dispersion method.