β-环糊精用于铜的二次微分简易示波伏安法测定

Application of β-Cyclodextrin to Determination of Cu^(2+) by Second Order Differential Simple Oscillographic Voltammetry

在 0 2mol LNaOH底液中 ,β 环糊精在dE dt E曲线上 - 0 38V处产生 1可逆切口 ,在阴极支的切口深度随Cu2 + 与 β 环糊精形成的包合物量的增加而减小。实验结果表明 ,β 环糊精在二次微分简易示波伏安图上的峰高与Cu2 + 浓度在 1 0× 10 - 6 ～ 2 0× 10 - 5mol L范围内呈线性关系 ,回归方程为h(v) =4 819-3 86 1× 10 4 c(mol L) ,R =- 0 9992 ,检出限为 8× 10 - 7mol L ,对 7 0× 10 - 6 mol LCu2 + 5次测定结果的RSD为2 1% ,回收率为 10 2 4 %。此外 ,利用随客体分子的加入 β 环糊精示波图的变化 ,可快速、直观的判断出主、客体间是否发生了包结反应 ,从而拓展了用电化学方法研究超分子包结物的范围。

In 0 2 mol/L NaOH, β CD can cause a pair of reversible incision on d E /d t E curve, and its depth would get shallow with increase of the inclusion complex of Cu 2+ β CD. A feasibe method for determination of Cu 2+ in silicon brass was founded based on this oscillographic characteristic. The linear range of concentration for Cu 2+ is 1 0×10 -6 ～2 0×10 -5 mol/L with detection limit 8 0×10 -7 mol/L. The correlation equation coefficient is h(v) =-3 861×10 4 c +4 819(mol/L) and r =-0 999 2. The RSD for 7 0× 10 -6 mol/L Cu 2+ is 2 1%(n=5), and average recovery 102 4%( n =5). Moreover, on addition of rutin to the 0.2mol/L NaOH solution of β cyclodextrin the inclusion reaction between rutin and β CD could be monitored by changing of the incision depth of β CD.