多壁碳纳米管-十二烷基苯磺酸钠修饰的碳糊电极为工作电极测定磺胺甲噁唑

Determination of Sulfamethoxazole with Multi-Walled Carbon Nanotubes Sodium Dodecyl Benzene Sulfonate Modified Carbon Paste Electrode as Working Electrode

取1g·L^(-1)多壁碳纳米管悬浮液2μL,滴涂在自制的碳糊电极表面,待溶剂挥发后即得多壁碳纳米管修饰的碳糊电极(MWCT-CPE)。再在其表面滴涂1g·L^(-1)十二烷基苯磺酸钠溶液2μL,即制成MWCT-SDBS-CPE修饰电极。结果表明:碳糊电极经多壁碳纳米管和十二烷基苯磺酸钠修饰后,降低了电荷转移电阻,有利于电子传递。以0.005mol·L^(-1)硝酸钠为支持电解质,在pH 5.0的乙酸-乙酸钠缓冲溶液中进行微分脉冲伏安法(DPV)测定时,该修饰碳糊电极对磺胺甲噁唑(SMZ)具有良好的电化学响应。SMZ的线性范围为2.0×10^(-9)~1.0×10^(-7) mol·L^(-1)和1.0×10^(-7)~1.0×10^(-5) mol·L^(-1),方法的检出限为1.0×10^(-9) mol·L^(-1)。对6.0×10^(-6) mol·L^(-1)SMZ标准溶液连续测定5次,测定值的相对标准偏差为4.9%。

The self-made carbon paste electrode（CPE）was applied with a layer of multi-walled carbon nanotubes（MWCT）by dropping 2μL of 1g·L-1 MWCT suspension onto its surface.After volatilization of the solvent,2μL of 1g·L-1SDBS solution were applied to the surface by dropping and thus the modified electrode of MWCT-SDBS-CPE was prepared.It was found that through modification with MWCT and SDBS,change transfer of the electrode was decreased,resulting acceleration of electron transmission.As shown by the results of DPV in an acetate buffer solution of pH 5.0（containing 0.005 mol· L-1 NaNO3 as supporting electrolyte）,good electrochemical response of sulfamethoxazole（SMZ）was obtained at MWCT-SDBS-CPE.Linearity ranges of SMZ were found in the ranges of 2.0×10-9 to 1.0×10-7 mol·L-1and 1.0×10-7 to 1.0×10-5 mol·L-1,with detection limit of 1.0×10-9 mol·L-1.Precision was tested at 6.0×10-6mol·L-1 of SMZ for 5determinations,value of RSD found was 4.9%.