甲氧苄啶的电化学行为研究及伏安法测定

Study on electrochemical behavior of trimethoprim and its determination via voltammetric method

将裸玻碳电极在0. 2 mol/L NaH2PO4-Na2HPO4溶液中于+1. 7 V恒电位处理400 s后,得到电活化玻碳电极(EGCE)。以EGCE为工作电极,研究了缓冲溶液、pH、富集时间、富集电压和扫描速度对甲氧苄啶(TMP)测定的影响。结果表明,EGCE对TMP有较高的电化学响应。通过差分脉冲伏安法测试,TMP的氧化峰电流与浓度分别在1. 25×10-7~3. 0×10-5mol/L、3. 0×10-5~1. 0×10-4mol/L范围内呈良好的线性关系,检出限为8. 2×10-8mol/L(S/N=3)。该方法操作简单、快速,用于检测TMP的重现性和稳定性好。

An electro-activated glassy carbon electrode(EGCE)is prepared through activating a bare glassy carbon electrode(GCE)in a 0.2 mol·L-1 NaH2PO4-Na2HPO4 buffer solution for 400 s by potentiostatic method at+1.7 V.By using ECGE as working electrode,the effects of buffer solution,p H,accumulation time,accumulation voltage and scanning rate on trimethoprim(TMP)detection are investigated.Study results show that EGCE has a higher electrochemical response to TMP than GCE.By differential pulse voltammetry,it is found that a linear relation exists between the oxidative peak current and the concentration of TMP under the optimal conditions,and the linear ranges are1.25×10-7 to 3.0×10-5 mol·L-1,3.0×10-5 to 1.0×10-4 mol·L-1,respectively.The detection limit is 8.2×10-8 mol·L-1(S/N=3).This method is simple,fast,reproducible and stable for detection of TMP.