Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
Talanta. 2001 Mar 30;54(1):115-23. doi: 10.1016/s0039-9140(00)00658-5.
A new method for the determination of 4-nitrophenol(4-NP) by differential pulse voltammetry (DPV) based on adsorptive stripping technique was described. Cyclic voltammetry (CV) and linear scan voltammetry (LSV) were used in a comparative investigation into the electrochemical reduction of 4-NP at a Na-montmorillonite(SWy-2) and anthraquione (AQ) modified glassy carbon electrode. With this chemically modified electrode, 4-NP was first irreversibly reduced from phiNO(2) to phiNHOH at -0.78 V. A couple of well-defined redox peaks at +0.22 V (vs. SCE) were responsible for a two-electron redox peak between phiNHOH and phiNO. Studies on the effect of pH on the peak height and peak potential were carried out over the pH range 2.0-9.0 with the phosphate buffer solution. A pH of 3.4 was chosen as the optimum pH. The other experimental parameters, such as film thickness, accumulation time and potential etc. were optimized. Anodic peak currents were found to be linearly related to concentration of 4-NP over the range 0.3-45 mg l(-1), with a detection limit of 0.02 mg l(-1). The interference of organic and inorganic species on the voltammetric response have been studied. This modified electrode can be used to the determination of 4-NP in water samples.
一种基于吸附溶出技术的差分脉冲伏安法（DPV）测定 4-硝基酚（4-NP）的新方法。采用循环伏安法（CV）和线性扫描伏安法（LSV）对 4-NP 在钠蒙脱石（SWy-2）和蒽醌（AQ）修饰玻碳电极上电化学还原的进行了比较研究。在这种化学修饰电极上，4-NP 首先在-0.78V 不可逆地从 phiNO(2)还原为 phiNHOH。在+0.22V（相对于 SCE）处有一对定义明确的氧化还原峰，这是 phiNHOH 和 phiNO 之间的两个电子氧化还原峰。研究了 pH 值对峰高和峰电位的影响，实验在 pH 值为 2.0-9.0 的磷酸盐缓冲溶液中进行。选择 pH 值为 3.4 作为最佳 pH 值。还优化了其他实验参数，如膜厚度、积累时间和电位等。发现阳极峰电流与 4-NP 的浓度在 0.3-45mg l(-1)范围内呈线性关系，检测限为 0.02mg l(-1)。研究了有机和无机物质对伏安响应的干扰。这种修饰电极可用于水样中 4-NP 的测定。
