嵌入式碳纳米管电极差分脉冲伏安法测定湖泊沉积物中铅

制备嵌入式多壁碳纳米管修饰石墨电极（ESCFE），利用循环伏安法研究铅（Pb）的电化学行为及反应机理，结果表明，铅在修饰电极表面出现了一对明显的准可逆的氧化还原峰，发生了2质子的电化学氧化反应。用差分脉冲伏安法研究了铅离子浓度与其峰电流的线性关系，线性范围为1．8×10^-7～1．0×10^-5g／L，线性方程为：ipa（μA）=0．12＋1．471c×10^6（g/L），r=0．9999，检出限为6．0×10^-8g／L，RSD％为1．015（n=5）。利用本法对湖泊沉积物中铅进行测定，样品铅含量：0．218～0．6317mg／kg，RSD：3．3％～6．2％，加标回收率：94．3％-106．6％。

Different Pulse Voltammetry Determination of Lead in Lake Sediment with Inlaid Carbon Nanotubes Modified Graphite Electrode

The inlaid multi -wall carbon nanotubes modified graphite electrode （ESCFE） was prepared, and the electrochemical behavior and reaction mechanism of lead were investigated by cyclic voltammetry at ESCFE. A couple of sensitive and quasi - reversible peaks were observed with tow protons. Differential pulse voltammetry （DPV） was used to determinate the contents of lead. The oxidization peak current was linear with the concentration of lead in the range of 1.8×10^-7～1.0×10^-5g/L, the detection limit was 6.0×10^-8g/L, and the RSD% （n =5） was 1. 015. Trace lead in samples were successfully determined with satisfactory results. The proposed method was applied to determine lead in lake sediments, the Pb content, RSD and recoveries of the samples were 0. 218 0. 6317 mg/kg, 3.3 -6.2% and 94. 3 - 106.6% , respectively.