双硫腙修饰丝网印刷电极同时检测茶汤中的Cu(Ⅱ)和Pb(Ⅱ)

Simultaneous Detection of Copper and Lead ions Using Dithizone Modified Screen-printed Electrode

在乙酸-乙酸钠缓冲溶液(0.1 mol/L、pH 5.0)中,利用双硫腙修饰丝网印刷电极阳极溶出伏安法分别于-0.18 V、-0.76 V阳极溶出峰同时测定重金属离子Cu2+和Pb2+。通过优化测定条件,得到最佳参数为:双硫腙修饰量3μg、pH 5.0、富集电位-1.1 V、富集时间210 s。在此条件下,Cu2+和Pb2+浓度分别在1.0×10-10-1.0×10-5mol/L、1.0×10-10-1.0×10-6mol/L范围内与峰电流呈良好的线性关系(RCu=0.9991,RPb=0.9934),检测限分别为0.35×10-10mol/L、0.41×10-10mol/L。该方法简单、快速、灵敏,可用于检测茶汤中的Cu2+和Pb2+。

The contaminant metal copper and lead ions were determined simultaneously using dithizone modified screen-printed electrode（SPE） by anodic stripping voltammetry（ASV） in the HAc-NaAc buffer solution（0.1 mol/L,pH 5.0）.Copper and lead ions had sensitive anodic stripping peak at-0.18 V and-0.76 V,respectively.The optimum parameters by optimizing the conditions of the detecting method were as follows,dithizone modification quantity 3 μg,pH 5.0,electrodeposition potential-1.1 V and electrodeposition time 210 s.Under the optimum conditions,a good linear retationship was obtained between the concentration of Cu2＋ and Pb2＋ ranged in 1.0×10-10-1.0×10-5 mol/L and 1.0×10-10-1.0×10-6mol/L,respectively,with stripping peak current（RCu= 0.9991,RPb= 0.9934）.The detection limits for Cu2＋and Pb2＋were of 0.35×10-10mol/L and 0.41×10-10mol/L,respectively.The method was simple,fast and sensitive for the determination of Cu and Pb in tea.