【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%。更多还原

【Abstract】 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 %.更多还原