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通过两步电沉积方法制备了一种灵敏的铋/多壁碳纳米管复合膜修饰电极.首先用电解代替滴涂法将多壁碳纳米管沉积到玻碳电极表面,然后再把铋膜沉积到多壁碳纳米管上.提出了利用方波阴极吸附溶出伏安法分别测定水中总铬和六价铬的分析方法.在铜铁灵试剂的存在下,Cr(Ⅲ)和铜铁灵形成的络合物在-0.35V时通过吸附富集在修饰电极的表面,然后在阴极扫描(-0.35~-1.10V)过程中被还原.可以利用Cr(Ⅲ)或Cr(Ⅵ)的标准加入法直接测定水中总铬含量,也可以利用阴离子富集柱将Cr(Ⅵ)与Cr(Ⅲ)分离后单独测定水中Cr(Ⅵ)含量,分析结果与电感耦合等离子体质谱法(ICP-MS)相吻合.本法的检测下限在富集时间2min时为0.05μg/L,相对标准偏差为5.2%(n=75).
A sensitive bismuth / multiwalled carbon nanotube composite film modified electrode was prepared by a two-step electrodeposition method. First, multi-walled carbon nanotubes were deposited on the surface of glassy carbon electrode by electrolysis instead of the dropping method, and then the bismuth film was deposited To multi-walled carbon nanotubes (CNTs) .A analytical method for the determination of total chromium and hexavalent chromium in water by square wave cathodic adsorption stripping voltammetry was proposed. The formation of Cr (Ⅲ) Complex is enriched by adsorption on the surface of the modified electrode at -0.35 V and then reduced during the cathodic scan (-0.35 to -1.10 V). It can be added using the standard of Cr (III) or Cr (VI) Method can be used to directly determine the total chromium in water. The content of Cr (Ⅵ) in water can also be measured separately after the separation of Cr (Ⅵ) and Cr (Ⅲ) using an anion-enriched column. The results of the analysis are in good agreement with the results of inductively coupled plasma mass spectrometry (ICP- .The detection limit of this method was 0.05μg / L at 2min enrichment time and the relative standard deviation was 5.2% (n = 75).