多壁碳纳米管负载氢氧化铁纳米胶粒修饰玻碳电极固相微萃取及电化学检测三氯生

采用多壁碳纳米管负载氢氧化铁纳米胶粒修饰的玻碳电极对三氯生进行固相微萃取富集,其萃取过程符合一级动力学方程和Temkin吸附等温方程。循环伏安法表明三氯生在0.558 V处有一不可逆的氧化峰,pH值与氧化峰电位呈良好的线性关系,表明三氯生的氧化过程为1个电子伴随着1个质子的反应。氧化峰电流随扫速增加而线性增加,为吸附控制反应,氧化峰电流与三氯生浓度的对数在3.333×10~(-6)~3.333×10~(-4)mol/L范围内呈线性关系,检出限达3.333×10~(-6)mol/L。该方法的重现性及选择性好,已用于洗手液中三氯生的检测。以MOPAC2012软件提供的PM7半经验分子轨道方法,在设计的三氯生与氢氧化铁纳米胶粒形成的络合物分子簇模型上进行半经验分子轨道计算,热力学及前线轨道相关系数的计算结果表明:形成的三氯生络合物的ΔG0,证明形成了稳定的三氯生络合物;且三氯生络合物形成过程中发生了电子转移。

Determination of Triclosan by Cyclic Voltammetry with Solid Phase Micro-extraction on Multi-walled Carbon Nanotubes Supported Ferric Hydroxide Nanoparticles Modified Glassy Carbon Electrode

In this paper,the enrichment behavior of triclosan on multi-walled carbon nanotubes supported ferric hydroxide nanoparticles modified glassy carbon electrode was investigated by cyclic voltammetry with solid-phase microextraction.The extraction process was observed to follow the first-order kinetic equation based on Temkin isothermal adsorption model.The cyclic voltammogram of triclosan on the modified electrode showed an irreversible oxidation peak at about 0.558 V.The linearity existed between the pH values and the oxidation peak potential indicated that the oxidation of triclosan was a transferred process of one electron accompanied by a proton.The oxidation peak current increased linearly with the increase of sweep rate,indicating that the oxidation reaction was controlled by surface adsorption.The linear relationship between the oxidation peak current and the logarithm of triclosan concentration in the range of 3.333 × 10-6-3.333 × 10-4 mol/L could be used to determine the concentration of triclosan with the detection limit of 3.333 × 10-6 mol/L.The method was used in detection of triclosan in hand sanitizers with good reproducibility and selectivity.Based on the cluster models of triclosan and ferric hydroxide nanoparticles,semi-empirical molecular orbital calculations were performed with PM7 in MOPAC2012.The thermodynamic and front orbit correlation coefficient results showed that a complex formed between triclosan and ferric ions was stable with the AG ＜ 0,and the electron transfer occurred in the formation of the triclosan complex.