聚多巴胺修饰电极对痕量铅的测定研究

Study of Trace Lead Determination by Polydopamine Modified Electrode

通过多巴胺（DA）的自聚反应在玻碳电极（GCE）表面修饰一层聚多巴胺（PDA）膜,对DA的自聚条件和方波溶出伏安法测试条件进行优化。优化的实验条件为：以2 mg/mL DA的Tris-HCl（0.01 mol/L,p H8.5）溶液为自聚溶液,自聚反应时间为2.5 h,铅的测试底液为0.1 mol/L HCl溶液,修饰电极在铅测试溶液中于-1.0 V富集300 s时,溶出峰的峰形好,且峰电流大。峰电流与铅浓度分别在0.1-1.0μg/L和1.0-10.0μg/L范围内呈良好的线性关系,检出限为0.016 5μg/L。实验结果表明,该聚多巴胺修饰电极制备简单、灵敏度高、成本低,可用于加碘盐、纯净水和自来水中痕量铅的测定。

A polydopamine （PDA） modified glassy carbon electrode （GCE） was fabricated by self- polymerization of dopamine （DA） and was used to detect the trace lead in iodized salt, pure water and tap water. The experiment conditions of seE-polymerization of DA and square wave stripping voltammetry were optimized. The optimal conditions were as follows： self-polymerization solution： Tris - HCI（0. 01 mol/L, pH 8.5） containing 2 mg/mL DA; self-polymerization time： 2. 5 h; reaction medium of lead ： 0. 1 mol/L HCl solution; accumulation potential ： - 1.0 V ; accumulation time ： 300 s. The type of dissolution peak is good and the peak current is high under the optimal conditions. The peak current is proportional to concentration of lead in the ranges of 0. 1 - 1.0 μg/L and 1.0 - 10. 0 μg/L, with a detection limit of 0. 016 5 μg/L. The results showed that the new method introduced is simple, sensitive and low cost, and could be applied in the determination of trace lead in iodized salt, pure water and tap water.