Baldrianova L, Svancara I, Sotiropoulos S
Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice, Czech Republic.
Anal Chim Acta. 2007 Sep 19;599(2):249-55. doi: 10.1016/j.aca.2007.07.067. Epub 2007 Aug 3.
A new type of disposable carbon paste mini-electrodes (CPmEs), with dimensions in the 50-300 microm range, have been fabricated by heat-shrinking the end-tip of plastic micropipette tips and filling them with carbon paste. The CPmEs have been characterized by microscopic and electrochemical means and tested as substrates for in situ plated Bi film electrodes (BiF-CPmEs), used in the determination of heavy metals by square wave anodic stripping voltammetry (SWASV). It was found that this new class of CPmEs combines the advantages of carbon paste electrodes (readily renewable surface and high surface area) with those of near-microelectrode behaviour (no stirring or electrolyte excess needed). During SWASV experiments in unstirred Pb(II) and Cd(II) solutions well-shaped stripping peaks were obtained whose height varied linearly with analyte concentration in the wide 1x10(-8) to 10(-6) M range, both in acetate buffer and unbuffered solutions. Under optimal conditions detection limits of 8x10(-10) and 1.3x10(-9) M were achieved for Pb(II) and Cd(II), respectively and in a trial application, these metal ions have been determined in a spiked tap water sample using a BiF-CPmE.
一种新型的一次性碳糊微电极（CPmEs），尺寸在50 - 300微米范围内，通过热缩塑料微量移液器尖端的末端并填充碳糊制成。已通过显微镜和电化学方法对CPmEs进行了表征，并将其作为原位镀铋膜电极（BiF - CPmEs）的基底进行测试，用于方波阳极溶出伏安法（SWASV）测定重金属。结果发现，这类新型CPmEs结合了碳糊电极（表面易于更新且表面积大）和近微电极行为（无需搅拌或过量电解质）的优点。在未搅拌的Pb(II)和Cd(II)溶液中进行SWASV实验时，获得了形状良好的溶出峰，其高度在1×10⁻⁸至10⁻⁶ M的宽范围内随分析物浓度呈线性变化，无论是在醋酸盐缓冲溶液还是未缓冲溶液中。在最佳条件下，Pb(II)和Cd(II)的检测限分别达到8×10⁻¹⁰和1.3×10⁻⁹ M，并且在一次试验应用中，使用BiF - CPmE测定了加标自来水样品中的这些金属离子。
