石墨烯/铋复合膜修饰玻碳电极检测板蓝根中的铅和镉

Simultaneous Determination of Pb^(2+) and Cd^(2+) in Isatis Root by a Bismuth/Graphene Composite Film Modified Glassy Carbon Electrode

采用滴涂法制备石墨烯(GR)修饰的玻碳电极(GCE),通过电化学富集Bi沉积在GR表面,得到GR/Bi-GCE修饰电极。用方波溶出伏安法研究了Cd2+和Pb2+在GR/Bi-GCE上的电化学行为。在0.1 mol/L p H 4.5的醋酸缓冲溶液中,在!1.1 V富集0.5 mg/L Bi(NO3)3溶液210 s后,溶出峰电流与Cd2+和Pb2+的浓度在0.01~85.0μmol/L范围内呈良好的线性关系,检出限均为0.003μmol/L。实验结果表明,此修饰电极对Cd2+和Pb2+均有较好的电化学活性,可对两种物质实现同时测定,具有较高的灵敏度和稳定性。将此电极用于板蓝根中Cd2+和Pb2+的含量测定,结果令人满意。

A glassy carbon electrode（ GCE） was first modified with graphene（ GR） by drop coating method,and then Bi film was deposited on the GR layer by direct electrodeposition method to get the modified electrode GR / Bi-GCE. The electrochemical behavior of Cd^2 ＋and Pb^2 ＋on GR / Bi-GCE was studied with square wave stripping voltammetry. In 0. 1 mol / L,p H 4. 5 Na Ac-HAc buffer solution,the stripping peak current at!1. 1 V for 210 s in 0. 5 mg / L Bi（ NO3）3showed good linear relationship with Cd^2 ＋and Pb^2 ＋concentrations in the range of 0. 01- 85 μmol / L,and the detection limits were both at 0. 003 μmol / L. The results showed that this modified electrode had good electrochemical activity toward Cd^2 ＋and Pb^2 ＋,and could achieve simultaneous determination of Cd^2 ＋and Pb^2 ＋. The GR / Bi-GCE showed good stability and sensitivity. It was used for the determination of Cd^2 ＋and Pb^2 ＋in real isatis root samples with satisfactory results.