槲皮素在分子印迹聚合物修饰碳糊电极上的电化学行为及测定

Electrochemical behavior and determination of quercetin by molecularly imprinted polymer modified carbon paste electrode

建立分子印迹聚合物修饰碳糊电极测定药物中槲皮素含量的新方法。以槲皮素为模板分子,甲基丙烯酸为功能单体,偶氮二异丁腈为引发剂,乙二醇二甲基丙烯酸酯为交联剂,通过沉淀聚合法制得槲皮素分子印迹聚合物,以m(石墨+聚合物):m(石蜡)=4∶1比例混合制成的印迹聚合物修饰碳糊电极作为工作电极。在0 V富集150 s,然后从0~0.6 V以100 m V/s扫速线性扫描,记录其在0.338 V的峰电流。槲皮素物质量浓度在1.25×10-6~4.0×10-5 mol/L与峰电流呈良好的线性关系(r=0.995 0),检出限为4.72×10-8mol/L,应用该方法测定胶囊中槲皮素的含量,测得回收率为96.7%~105.6%。该修饰电极具有较高的选择性和灵敏度,可用于槲皮素的测定。

To find a new way to determine trace amounts of quercetin in medicine using molecularly imprinted polymer modified carbon paste electrode. Quercetin is taken as template molecular,methacrylic acid as functional monomer,azobisisobutyronitrile as initiator and ethyleneglycol dimethacrylate as cross-linked agent to prepare quercetin molecular imprinted polymer via precipitation polymerization. The polymer obtained is further mixed with graphite and paraffin at the ratio of m(graphite+polymer)∶m(paraffin)=4∶1 to get the imprinted polymer modified carbon paste electrode to be used as work electrode. The mixture is enriched for 150 s at 0 V and then linearly scanned from 0-0.6 V at 100 m V/s. After that,the peak current at 0.338 V is recorded. The peak current shows a good linear relationship(r=0.995 0) with the concentration of quercetin in the range of 1.25 ×10-6-4.0 ×10-5mol/L. The detection limit is 4.72 ×10-8mol/L. The method is applied to determine the quercetin in capsules and the recovery of queercetin is 96.7%-105.6%. The modified electrode can be applied to determine quercetin because of its higher selectivity and sensitivity.