Feeney R, Kounaves SP
Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA.
Anal Chem. 2000 May 15;72(10):2222-8. doi: 10.1021/ac991185z.
Rapid on-site analysis of arsenic in groundwater was achieved with a small battery-powered unit in conjunction with a microfabricated gold ultramicroelectrode array (Au-UMEA). The sensor, consisting of 564 UME disks with a unique gold surface created by electron beam evaporation, was demonstrated to be highly sensitive to low-ppb As3+ using square wave anodic stripping voltammetry. The influence of the square wave frequency, pulse amplitude, and deposition potential on the arsenic peak stripping current was investigated. Varying those theoretical parameters yielded results surprisingly similar to those for the thin Hg film case. The performance of the Au-UMEA was evaluated for reproducibility and reliability. Three stability tests showed an average relative standard deviation of 2.5% for 15 consecutive runs. Limits of detection were investigated, and 0.05 ppb As3+ could be measured while maintaining a S/N of 3:1. Interference studies were performed in the presence of 50-500 ppb of Cu2+, Hg2+, and Pb2+. On-site analysis of groundwater containing arsenic was performed with a small battery-powered potentiostat. Quantification was done through standard additions, and these results were compared to the standard EPA methodology.
使用一个由电池供电的小型装置与一个微纳加工的金超微电极阵列（Au - UMEA）相结合，实现了对地下水中砷的快速现场分析。该传感器由564个UME圆盘组成，通过电子束蒸发形成独特的金表面，采用方波阳极溶出伏安法对低ppb水平的As3 +表现出高度敏感性。研究了方波频率、脉冲幅度和沉积电位对砷峰溶出电流的影响。改变这些理论参数得到的结果与薄汞膜情况惊人地相似。对Au - UMEA的性能进行了重复性和可靠性评估。三次稳定性测试表明，连续15次运行的平均相对标准偏差为2.5%。研究了检测限，在保持信噪比为3:1的情况下，可以测量0.05 ppb的As3 +。在存在50 - 500 ppb的Cu2 +、Hg2 +和Pb2 +的情况下进行了干扰研究。使用一个由电池供电的小型恒电位仪对含砷地下水进行现场分析。通过标准加入法进行定量，并将这些结果与美国环保署的标准方法进行比较。
