聚氯乙烯膜修饰碳微电极的研制及应用

采用浸涂流延法制得ＰＶＣ膜修饰碳微电极，用Ｋ３Ｆｅ（ＣＮ）６的循环伏安图考察了电极的电化学性能，并用此电极建立了环境水样中痕量汞的阳极溶出伏安法测定。在０．０６ｍｏｌ／Ｌ ＫＳＣＮ＋０．０１ｍｏｌ／ＬＫＣｌ介质中，富集电位－０．８０Ｖ，搅拌富集时间３００ｓ，扫描电压范围－０．２０～０．４０Ｖ，扫描速率３１４ｍＶ／ｓ，咄峰电流与Ｈｇ＾２＋浓度在０．０１～２．０ｍｇ／Ｌ的范围内有良好的线性关系，本电极

Development and Application of Polyvinyl Chloride Film Modified Carbon Microelectrode

By the flow-spreading over the carbon powder microelectrode with the tetrahydrofuran solution of 1.5% polyvinyl chloride (PVC) and 1% dioctylphthalate, a polyvinyl chloride film modified carbon microelectrode (PCFMCE) has been prepared. The cyclic voltammetry of PCFMCE in 10 mmol/L K3Fe(CN)6+1 mol/L KCI solution showed that the electrode process was semi-reversible, and the main process was diffusion controlled. An anodic stripping volammetry (ASV) technique by using PCFMCE for the determination of trace amounts of Hg2+ in water samples has been established. In a supporting electrolyte of 0.06 mol/L KSCN and 0.01 mol/L KCI, a sensitive oxidation wave of mercury was found by ASV. The peak potential was at + 0. 12(vs. SCE). Under the conditions of enriching potential - 0. 8 V, strirring time 300 s, scaning potential range - 0.20 - 0. 40 V and scan rate 314 mV/s, the linear relationship between the anodic stripping current and concentration for mercury existed over the range of 0.01 - 2.0 mg/L. The detection limit was 0.01 mg/L. This method has ho successfully applied to the direct determination of trace amounts of mercury in environmental waters. The novel microelectrode shows high stability and selectivity. The electrode is easy to make, and inexpensive.