锌-槲皮素-氯酸钾体系吸附催化波法测定痕量锌

Determination of trace zinc using adsorptive catalytic wave of Zn-quercetin-potassium chlorate system

在pH 7.7的磷酸盐缓冲溶液中,锌(Ⅱ)与槲皮素所形成的络合物在-1.15V(vs.SCE)产生吸附波,加入氯酸钾后该波峰电流增加,其二阶导数峰电流与锌(Ⅱ)浓度在8.0×10-9～6.0×10-6 mol/L范围内呈线性关系,检出限(3s/N)为5.0×10-9 mol/L。研究了极谱波的性质及增敏的机理,表明该波为络合物吸附催化波。方法用于天然水样中锌含量的测定,测定结果与原子吸收光谱法一致。以样品为基体,用标准加入法做回收率试验,测得方法的回收率在96%～105%之间。

In pH 7. 7 Na2HPO4-NaH2PO4 buffer solution, the complex formed from Zn（Ⅱ） and querce- tin produced an adsorptive polarographic wave at the peak potential --1.15 V （vs. SCE） and the peak current of the wave increased after addition of KClO3. Values of 2nd derivative of peak current were found to keep linear relationship with the concentration of Zn（Ⅱ） in the range of 8.0 ×10-9- 6.0 × 10-6 mol/L, with its detection limit （3s/N） of 5.0 × 10.9 mol/L. The results for study of adsorptive and catalytic properties of polarographic wave showed that the wave was adsorptive catalytic wave. The proposed method was used to the analysis of Zn（Ⅱ） in natural water samples. The results were in con- sistency with those obtained by AAS. Tests for recovery were carried out by addition of Zn（Ⅱ） standard solution to the sample as matrix, giving recovery of 95.7%-104.6%.