Garnier C, Lesven L, Billon G, Magnier A, Mikkelsen O, Pizeta I
Equipe de Chimie Analytique et Marine UMR8013, Université des Sciences et Technologies de Lille, Cité Scientifique 59655, Villeneuve d'Ascq, France.
Anal Bioanal Chem. 2006 Sep;386(2):313-23. doi: 10.1007/s00216-006-0625-9. Epub 2006 Jul 25.
Voltammetric procedures for trace metals analysis in polluted natural waters using homemade bare gold-disk microelectrodes of 25- and 125-microm diameters have been determined. In filtered seawater samples, square wave anodic stripping voltammetry (SWASV) with a frequency of 25 Hz is applied for analysis, whereas in unfiltered contaminated river samples, differential pulse anodic stripping voltammetry (DPASV) gave more reliable results. The peak potentials of the determined trace metals are shifted to more positive values compared to mercury drop or mercury-coated electrodes, with Zn always displaying 2 peaks, and Pb and Cd inversing their positions. For a deposition step of 120 s at -1.1 V, without stirring, the 25-microm gold-disk microelectrode has a linear response for Cd, Cu, Mn, Pb and Zn from 0.2 microg L(-1) (1 microg L(-1) for Mn) to 20 microg L(-1) (30 microg L(-1) for Zn, Pb and 80 microg L(-1) for Mn). Under the same analytical conditions, the 125-microm gold-disk microelectrode shows linear behaviour for Cd, Cu, Pb and Zn from 1 microg L(-1) (5 microg L(-1) for Cd) to 100 microg L(-1) (200 microg L(-1) for Pb). The sensitivity of the 25-microm electrode varied for different analytes from 0.23 (+/-0.5%, Mn) to 4.83 (+/-0.9%, Pb) nA L micromol(-1), and sensitivity of the 125-microm electrode varied from 1.48 (+/-0.7%, Zn) to 58.53 (+/-1.1%, Pb nA L micromol(-1). These microelectrodes have been validated for natural sample analysis by use in an on-site system to monitor Cu, Pb and Zn labile concentrations in the Deûle River (France), polluted by industrial activities. First results obtained on sediment core issued from the same location have shown the ability of this type of microelectrode for in situ measurements of Pb and Mn concentrations in anoxic sediments.
已确定使用自制的直径为25微米和125微米的裸金盘微电极对受污染天然水中痕量金属进行伏安分析的程序。在过滤后的海水样品中，采用频率为25Hz的方波阳极溶出伏安法（SWASV）进行分析，而在未过滤的受污染河流样品中，差分脉冲阳极溶出伏安法（DPASV）给出了更可靠的结果。与汞滴或汞膜电极相比，所测定痕量金属的峰值电位向更正的值移动，其中锌总是显示出2个峰，铅和镉的位置颠倒。对于在-1.1V下120s的沉积步骤，在不搅拌的情况下，25微米的金盘微电极对镉、铜、锰、铅和锌的线性响应范围为0.2微克/升（锰为1微克/升）至20微克/升（锌、铅为30微克/升，锰为80微克/升）。在相同的分析条件下，125微米的金盘微电极对镉、铜、铅和锌的线性响应范围为1微克/升（镉为5微克/升）至100微克/升（铅为200微克/升）。25微米电极对不同分析物的灵敏度从0.23（±0.5%，锰）到4.83（±0.9%，铅）纳安·升·微摩尔⁻¹不等，125微米电极的灵敏度从1.48（±0.7%，锌）到58.53（±1.1%，铅）纳安·升·微摩尔⁻¹不等。这些微电极已通过用于现场系统监测法国德勒河受工业活动污染后的铜、铅和锌的活性浓度，从而在天然样品分析中得到验证。从同一地点获取的沉积物岩心的初步结果表明，这种类型的微电极能够原位测量缺氧沉积物中的铅和锰浓度。
