基于差分脉冲伏安法检测奶粉中三聚氰胺的研究

Determination of melamine in milk powder based on differential pulse voltammetry

中文关键词:  差分脉冲伏安法  多壁碳纳米管  玻碳电极  三聚氰胺  奶粉

英文关键词:differential pulse voltammetry  multi-walled carbon nanotube  glassy carbon electrode  melamine  milk powder

中文摘要:

      目的 建立一种基于多壁碳纳米管(multi-walled carbon nanotube, MWNT)修饰电极的新型电化学传感平台, 用于乳制品中三聚氰胺(melamine, MEL)的快速检测。方法 本研究采用电化学循环伏安法(cyclic voltammetry, CV)和差分脉冲伏安法(differential pulse voltammetry, DPV), 利用MWNT修饰的玻碳电极(glassy carbon electrode, GCE)做探针, 成功构建MEL检测的电化学传感器, 并对实际样品奶粉中的MEL进行检测与分析。结果 裸GCE经MWNT修饰后有效面积可以提高1.3倍, MWNT修饰电极对体系电化学反应有促进作用, MWNT修饰电极做探针的MEL电化学传感器的线性范围是10~40 μmol/L、灵敏度为23.85 (μA/mmol)/cm2, 检测到实际奶粉样品中MEL的含量符合国家标准要求。结论 利用MWNT修饰电极构建MEL电化学传感器是可行的, 该MEL传感器构建方法简单、重复性和稳定性良好, 具有一定的抗干扰能力, 准确度优异, 建议推广使用。

英文摘要:

      Objective To establish a novel electrochemical sensing platform based on multi-walled carbon nanotube (MWNT) modified electrode for rapid detection of melamine (MEL) in dairy products. Methods An electrochemical sensor for MEL detection was constructed by employing cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques, using a MWNT-modified glassy carbon electrode (GCE) as the sensing probe. The constructed sensor was successfully applied to detect and analyze melamine in real-world milk powder samples. Results After modification with MWNT, the effective surface area of the bare GCE increased by 1.3 fold. The MWNT-modified electrode significantly enhanced the electrochemical reaction kinetics of the system. The MEL electrochemical sensor, using the MWNT-modified GCE as the probe, exhibited a linear detection range of 10–40 μmol/L and a sensitivity of 23.85 (μA/mmol)/cm2. The detected MEL content in real milk powder samples complied with the Chinese national standard requirements. Conclusion The construction of the MEL electrochemical sensor using MWNT-modified electrodes has been demonstrated to be feasible. The construction method of the MEL sensor is simple, the good repeatability and stability of the MEL sensor are exhibited, the anti-interference capability and accuracy of the MEL sensor are excellent. Based on above advantages, the MEL sensor is applied widely.