线性扫描溶出伏安法同时测定水样中铅镉铜锌

Simultaneous Determination of Lead,Cadmium,Copper and Zinc in Water Samples by Linear Sweep Stripping Voltammetry

通过多壁碳纳米管-Nafion复合膜修饰电极,建立水样中痕量铅、镉、铜、锌同时测定的线性扫描溶出伏安分析法,优化支持电解质及pH值、修饰剂用量、富集电位及时间等测定条件。实验结果表明,在pH 4.0的NaAc-HAc缓冲液中,-1.20V富集5min后,在电位-1.04V、-0.72V、-0.45V及-0.16V附近分别产生锌、镉、铅、铜的灵敏溶出峰,测定各元素的线性关系良好,相对标准偏差均小于5.4%。该法已成功应用于实际水样中痕量铅、镉、铜、锌的同时测定,加标回收率在93.3%～106.7%之间,结果满意。

A novel linear sweep stripping voltammetry was developed for simultaneous determination of trace lead,cadmium,copper and zinc in water samples by the multi-wall carbon nanotube（MWCNT）-Nafion film modified glassy carbon electrode（GCE）.The experimental parameters such as supporting electrolyte and buffer pH,the amount of MWCNT-Nafion suspension,accumulation potential and time,were optimized.The results showed that the stripping peaks appeared at-1.04 V for zinc,-0.72 V for cadmium,-0.45 V for lead and-0.16 V for copper respectively after 5 min accumulation at-1.20 V in pH 4.0 NaAc-HAc buffer.Satisfactory linearity of the calibration curves of four elements were obtained,the relative standard deviations of the results were less than 5.4%.The method has been applied to simultaneous determination of trace level of lead,cadmium,copper and zinc in water samples with satisfactory results and the recoveries are between 93.3 and 106.7%.