磷钼钒杂多酸-聚邻苯二胺修饰碳糊电极示差脉冲溶出伏安法测定对苯二酚和邻苯二酚

Differential Pulse Stripping Voltammetric Determination of Hydroquinone and Catechol with Moylbdovanadophosphoric HeteropolyacidPoly-1,2-Diaminobenzene Modified Carbon Paste Electrode

在由磷钼钒杂多酸和邻苯二胺组成的支持电解质中,以0.100V.s-1扫速在碳糊电极上,于0.800～-0.800V范围内循环扫描20周后,制得磷钼钒杂多酸-聚邻苯二胺修饰碳糊电极。循环伏安法研究发现:对苯二酚(HQ)和邻苯二酚(CC)在该修饰电极上均出现了一对氧化还原峰;示差脉冲溶出伏安法研究发现:HQ和CC分别在0.140V和0.288V处出现二次微分溶出峰,两峰电位差为0.148V。HQ和CC的线性范围均为1.50×10-7～7.50×10-4 mol.L-1,检出限(3S/N)均为6.80×10-8 mol.L-1。据此提出了示差脉冲溶出伏安法测定模拟水样中HQ和CC,测得回收率在94.0%～106.0%之间。

Moylbdovanadophosphoric heteropolyacid-poly-1,2-diaminobenzene modified carbon paste electrode was prepared by electrochemical polymerization with scanning rate of 0.100 V·s-1 in an electrolyte containing moylbdovanadophosphoric heteropolyacid and 1,2-diaminobenzene for 20 cycles in the potential range from 0.800 to-0.800 V.As shown by the result of CV study on the electrochemical behaviors of CC and HQ at the modified electrode,a pair of oxidation and reduction peaks was found for each of the 2 compounds.It was shown by DPSV study that sensitive 2nd derivative stripping peaks was observed at the potential of 0.140 V for HQ and 0.288 V for CC,giving a potential difference of 0.148 V.Linearity range for HQ and CC were same to be 1.50×10-7-7.50×10-4mol·L-1,with detection limits（3S/N） of 6.80×10-8mol·L-1.Based on these facts,DPSV method was used in the determination of HQ and CC in simulated water sample,giving values of recovery in the range of 94.0%-106.0%.