A novel sensitive method for the determination of cadmium and lead based on magneto-voltammetry
A novel sensitive method for the determination of cadmium and lead based on magneto-voltammetry
复制标题
DOI：
10.1080/00032710600964890
复制
发表时间：
2007-02-01
影响因子：
2
通讯作者：
Yin, Jian
中科院分区：
文献类型：
--
作者：
Gao, Yanping;Wei, Wanzhi;Yin, Jian
建立了基于磁伏安法超痕量测定Cd~(2+)和Pb~(2+)的新方法。在0.6T的低磁场下，用方波溶出伏安法测定了Cd~(2+)和Pb~(2+)。在预富集步骤中，将高浓度的氧化还原物种Fe3+添加到分析物中以产生大的阴极电流。由于磁流体力学的作用，净电流通过磁场时产生的大洛伦兹力导致了对流解的流动。然后观察到更多的金属离子以更快的速度沉积在电极表面，对溶出峰电流的提高高达160%。在最佳条件下，在1×10~(-8)-1×10~(-6)摩尔L(~(-1))范围内，对Cd~(2+)和Pb~(2+)的灵敏度分别为5.67mU·m~(-1)和6.98mU·m~(-1)。在预富集时间为2min时，对Cd~(2+)和Pb~(2+)的检出限分别为9.0×10~(-10)和8.6×10~(-10)mol.L(-1)。该方法用于实际水样中Cd~(2+)、Pb~(2+)的测定，结果与原子吸收光谱分析结果一致。
A novel method for the ultratrace determination of Cd2+ and Pb2+ based on magneto-voltammetry was developed. In the presence of a low strength magnetic field of 0.6 T, square wave stripping voltammetry (SWSV) of Cd2+ and Pb2+ was performed in this determination. A high concentration of redox species Fe3+ was added to the analytes to generate a large cathodic current during the preconcentration step. A large Lorentz force arising from the flux of net current through the magnetic field resulted in convective solution flow due to magnetohydrodynamics. Then more metal ions deposited on the electrode surface at a faster rate and an enhancement as large as 160% for the stripping peak current was observed. Under the optimal conditions, this method exhibits high sensitivities of 5.67 mu A mu M-1 for Cd2+ and 6.98 mu A mu M-1 for Pb2+, over the 1 x 10(-8) - 1 x 10(-6) mol l(-1) range. Detection limits as low as 9.0 x 10(-10) and 8.6 x 10(-10) mol l(-1) for Cd2+ and Pb2+ were obtained with a 2 min preconcentration time, respectively. The method was successfully applied to detect Cd2+ and Pb2+ in real water samples and the results were in agreement with atomic absorption spectrometry.