二氧化锡催化型碳糊电极测定苯酚

该文提出了以二氧化锡(SnO_2)作为催化型修饰剂改性碳糊电极,采用线性扫描伏安法直接测定苯酚的新方法,并对扫描速度、富集时间、以及pH等影响因素进行了研究。实验结果表明,在pH=5.0的0.2 mol/L磷酸盐缓冲溶液中,苯酚在+0.85V左右出现一个灵敏的氧化峰,其峰电流的大小接近同等条件下裸碳糊电极体系峰电流的2倍,灵敏度有明显提高。峰电流与苯酚浓度在5.0×10~(-6)～2.5×10~(-4)mol/L之间呈线性关系,该方法的相对标准偏差为5.53%,检出限为1.0×10~(-6)mol/L。并且低于5倍苯酚浓度的苯胺基本不干扰苯酚的测定(RSD=7.02%),将此方法用于模拟染料废水的测定也取得了良好的效果,回收率在99.1%～116.8%之间,相对误差为6%。

Voltammetric Detection of Phenol with Carbon Paste Electrode of SnO2-Modified

A new method for the determination of phenol with a SnO2 modified carbon paste electrode was developed. Factors such as scan rate, accumulation time, and pH have also been studied. The result showed that a sensitive oxidation peak of phenol appeared at ＋ 0.85 V in phosphate buffer （pH=5.0, 0.2 mol/L）, and its peak current was about 2 times as the peak current which under the same condition of bare carbon paste electrode system, and its sensitivity had been obviously improved. The oxidation peak current had a linear relationship with phenol concentration in the range of 5.0×10^-6～2.5×10^-4 mol/L and its low detection limit of 1.0×10^-6mol/L was obtained with RSD equals to 5.53 %. Phenyl amine, which concentration is less than 5 times of phenol＇s, would not impact the results. This electrode was applied to the determination of phenol in dye wastewater and the result was satisfactory, the recovery was between 99.1% and 116.8 %, the relative error was 6 %.