纳米四氧化三铁/离子载体修饰电极检测海水中痕量重金属铅

Nano-iron oxides/Nafion/ionophore modified electrode for anodic stripping voltammetric determination of lead in seawater

制备了一种纳米四氧化三铁/离子载体(nano-Fe3O4/ionophore)修饰的玻碳电极,利用阳极溶出伏安法实现了海水中的痕量铅离子的测定。利用纳米四氧化三铁的高比表面积和铅离子载体(ionophore)能够提供与铅离子配合的位点或仅供铅离子通过的空穴,有效地提高了检测重金属离子的灵敏度和选择性。实验结果表明,在0.1 mol/L的醋酸/醋酸钠缓冲液中(pH 4.5),氧化峰电流与铅离子浓度在3～60 nmol/L内呈良好线性关系(R=0.987),线性回归方程为ip=0.82 C+1.61,方法检出限达1 nmol/L。将制备的修饰电极用于实际海水中铅离子的检测,其结果与ICP-MS法所测值基本相吻合。

A nano-iron oxides/Nafion/ionophore modified electrode was developed for determining trace level of lead ions in seawater.Due to the strong adsorption property of the nano-iron oxides and the selective coordination ability of the lead ionophore,the nano-iron oxides/Nafion/ionophore modified electrode showed excellent selectivity and high sensitivity for lead.Under the optimized conditions,a linear response over a broad range between 3～60 nmol/L and detection limited of 1nmol/L was obtained.The modified electrode had been used to measure lead in seawater samples.