六氰合铁（Ⅱ）酸铁（Ⅲ）/全氟磺酸-聚四氟乙烯共聚物复...

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六氰合铁（Ⅱ）酸铁（Ⅲ）/全氟磺酸-聚四氟乙烯共聚物复合膜修饰玻碳电极差分脉冲伏安法测定铅和镉
刘雪 王兰 吴志伟 骆定法 黄克靖信阳师范学院化学化工学院,河南信阳464000

摘　要:利用电聚合的方法将普鲁士蓝修饰到玻碳电极表面,然后修饰上全氟磺酸-聚四氟乙烯共聚物（Nafion）膜制成修饰电极。利用差分脉冲伏安法（DPV）对Pb2＋和Cd2＋在该修饰电极上的电化学行为进行了研究,建立了差分脉冲伏安法灵敏测定Cd2＋和Pb2＋的新方法。对富集电位、富集时间以及Nafion用量等实验条件进行了优化。在0.1mol/L pH 4.5的NaAc-HAc缓冲液中,在-1.1V处搅拌富集450s,用DPV分别测定-0.48V和-0.73V处的氧化峰电流。溶出峰电流与Pb2＋和Cd2＋的浓度分别在5×10-8～5×10-5 mol/L和2×10-8～2×10-5 mol/L范围内呈良好的线性关系,相关系数分别为0.995和0.992。检出限分别为5×10-9 mol/L（Pb2＋）和2×10-9 mol/L（Cd2＋）（S/N=3）。方法用于水样中Cd2＋和Pb2＋的测定,测定值与原子吸收光谱法的结果相一致,相对标准偏差为2.1%～3.8%。[著者文摘]
关键词:普鲁士蓝 全氟磺酸-聚四氟乙烯共聚物（Nafion） 差分脉冲伏安法 铅 镉 化学修饰电极　　

Determination of lead and cadmium by differential pulse voltammetry based on hexakis（cyano-C）-iron potassium/Perfluorosulfonic acid-PTFE copolymer composite film modified glassy carbon electrodeLIU Xue,WANG Lan,WU Zhi-wei,LUO Ding-fa,HUANG Ke-jingDepartment of Chemistry,Xinyang Normal University,Xinyang 464000,ChinaAbstract:A modified electrode was prepared with glassy carbon electrode through modification first with Prussian blue by electro-polymerization method and then with Perfluorosulfonic acid-PTFE copolymer（Nafion） film.The electrochemical behavior of Pb2＋ and Cd2＋ on the prepared electrode was studied by differential pulse voltammetry（DPV）.A new determination method of Pb2＋ and Cd2＋ with high sensitivity was established.The experimental conditions such as accumulation potential,accumulation time and Nafion dosage were optimized.After stirring and accumulation at-1.1 V for 450 s in 0.1 mol/L NaAc-HAc buffer solution at pH 4.5,the oxidation peak currents at-0.48 V and-0.73 V were measured with DPV,respectively.The stripping peak current showed good linearity to the concentration of Pb2＋ and Cd2＋ in the range of 5×10-8-5×10-5 mol/L and 2×10-8-2×10-5 mol/L,respectively.The correlation coefficients were 0.995 and 0.992,respectively.The detection limits were 5×10-9 mol/L for Pb2＋ and 2×10-9 mol/L for Cd2＋（S/N=3）.The proposed method was applied to the determination of Cd2＋ and Pb2＋ in water sample.The results were consistent with those obtained by atomic absorption spectrometry,and the relative standard deviation（RSD） was 2.1 %-3.8 %.[著者文摘]

Key words: Prussian blue; Perfluorosulfonic acid-PTFE copolymer（Nafion）; differential pulse voltammetry; lead; cadmium; chemical modified electrode