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以金纳米粒子修饰玻碳电极为工作电极,采用超声-微分脉冲阳极溶出伏安法连续测定饮用水中痕量铅(Ⅱ)和铜(Ⅱ).通过原子力显微镜(AFM)对金纳米粒子的形貌和大小进行表征,对超声波提高伏安检测信号的工作机理作了比较详细的探讨.实验结果表明,超声波-伏安法提高了方法的灵敏度,与传统的微分脉冲伏安法相比,Pb(Ⅱ)和Cu(Ⅱ)的峰电流分别增大10倍和8倍.Pb(Ⅱ)和Cu(Ⅱ)离子在质量浓度10～250μg·L-1和5～200μg·L-1范围内成良好的线性关系,相关系数分别为0.9943和0.9985.在含有50μg·L-1Pb(Ⅱ)和20μg·L-1Cu(Ⅱ)的溶液中重复测定9次,其相对标准偏差为3.5%和2.2%,Pb(Ⅱ)和Cu(Ⅱ)的检出限分别为0.3ng·mL-1和0.1ng·mL-1.该方法成功应用于饮用水中痕量Pb(Ⅱ)和Cu(Ⅱ)的检测,方法简便可靠,具有实际应用意义。
Gold (Ⅱ) and copper (Ⅱ) in drinking water were continuously determined by ultrasonic-differential pulse anodic stripping voltammetry using gold nanoparticle-modified glassy carbon electrode as working electrode.Analytical results of atomic force microscopy (AFM) Morphology and size, the working mechanism of the ultrasonic voltammetry detection signal is discussed in detail.Experimental results show that ultrasonic-voltammetry increases the sensitivity of the method, compared with the traditional differential pulse voltammetry, Pb (Ⅱ) and Cu (Ⅱ) increased 10-fold and 8-fold, respectively.Pb (Ⅱ) and Cu (Ⅱ) ion concentrations in the range of 10 ~ 250μg · L-1 and 5 ~ 200μg · L-1 And the correlation coefficients were 0.9943 and 0.9985, respectively, and the relative standard deviations were 3.5% and 2.2 respectively in 9 replicates of the solution containing 50μg · L-1Pb (Ⅱ) and 20μg · L-1Cu (Ⅱ) The detection limits of Pb (Ⅱ) and Cu (Ⅱ) were 0.3 ng · mL -1 and 0.1 ng · mL -1, respectively. The proposed method was successfully applied to the determination of trace amounts of Pb (Ⅱ) and Cu The detection method is simple and reliable, and has practical significance.