邻苯二酚和对苯二酚在钴氢氧化物膜修饰玻碳电极上的选择性测定

通过镀膜/循环伏安法制备了钴氢氧化物膜修饰的玻碳电极。该修饰电极对邻苯二酚(CA)和对苯二酚(HQ)具有较强的电催化活性。考察了支持电解质酸度对邻苯二酚和对苯二酚电化学响应的影响,选用0.1 mol/LPBS(pH 10.0)作为支持电解质。利用差示脉冲伏安法(DPV)对邻苯二酚和对苯二酚进行选择性检测,当两者浓度同时改变时,邻苯二酚和对苯二酚在6～100μmol/L范围内氧化峰电流与其浓度呈良好的线性关系,检出限分别为2×10–7,5×10–7mol/L(S/N=3)。钴氢氧化物膜电极具有较好的稳定性、重现性及较强的抗干扰能力,将此修饰电极应用于模拟水样中邻苯二酚和对苯二酚的测定,回收率为95.4%～100.4%。

Selective Simultaneous Determination of Catechol and Hydroquinone at Cobalt Hydroxide Modified Glassy Carbon Electrode

Cobalt hydroxide modified glassy carbon electrode （CoOOH/GCE） was prepared by film plating/cyclic voltammetry method. CoOOH/GCE exhibited excellent electrocatalytic activities towards catechol （CA） and hydroquinone （HQ）. The effects of pH value on the oxidation peak current and potential of catechol and hydroquinone were studied by differential pulse vohammetry （DPV）, and 0.1 mol/L PBS （pH 10.0） was selected as the supporting electrolyte. Under the optimized conditions, when the concentrations of CA and HQ were simultaneously changed, the oxidation peak current of CA and HQ was linear with concentration repectively in the range of 6-100μmol/L with the detection limit of 2 × 10-7, 5 × 10-7 mol/L （S/N=3） repectively. Furthermore, the modified electrode exhibited good reproducibility, stability and selectivity, which was used for the determination of CA and HQ in imitative water samples with recoveries of 95.4%- 100.4%.