Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
Talanta. 2015 Jun 1;138:46-51. doi: 10.1016/j.talanta.2015.02.005. Epub 2015 Feb 9.
Electrochemical oxidation of adsorbed benzo(a)pyrene (BaP) on the glassy carbon electrode (GCE) was explored in acetonitrile-water. When the GCE was incubated in 100 nM BaP acetonitrile-water (V(water):V(acetonitrile)=1:1) for 10 min at open circuit, and then transferred into blank acetonitrile-water (V(water):V(acetonitrile)=1:1, pH= 0.70) for differential pulse voltammetry measurement, a distinct oxidation peak at 0.98 V (vs. Ag/AgCl) was observed. The peak potential was about 180 mV lower than that in acetonitrile. Importantly, the peak current was more than 22 times greater. The effects of water on BaP preconcentration on the electrode and electrochemical oxidation were revealed, respectively. Based on the results, an electrochemical assay for BaP detection was developed. The GCE was respectively incubated in acetonitrile-water (V(water):V(acetonitrile)=1:1)with BaP concentration ranged from 0 nM to 1000 nM, and then transferred into the corresponding blank acetonitrile-water (pH= 0.70) for DPV measurements. When the BaP concentration was increased, an increased oxidative current at 0.98 V (vs. Ag/AgCl) was observed, and a detection limit of 0.67 nM was achieved. Because all other priority polycyclic aromatic hydrocarbons could not be electrochemically oxidized at 0.98 V, the electrochemical assay showed very high selectivity to BaP. Finally, the developed electrochemical assay was successfully applied to determination of BaP in a series of real world samples, such as drinking water, tap water, lake water and river water.
在乙腈-水混合溶剂中探索了玻碳电极（GCE）上吸附的苯并[a]芘（BaP）的电化学氧化。当 GCE 在开路条件下于 100 nM BaP 的乙腈-水（V（水）：V（乙腈）=1:1）中孵育 10 分钟，然后转移到空白乙腈-水（V（水）：V（乙腈）=1:1，pH=0.70）中进行差分脉冲伏安法测量时，在 0.98 V（相对于 Ag/AgCl）观察到明显的氧化峰。峰电位比乙腈中低约 180 mV。重要的是，峰电流大 22 倍以上。分别揭示了水对电极上 BaP 预富集和电化学氧化的影响。基于这些结果，开发了一种用于 BaP 检测的电化学分析方法。GCE 分别在含有 BaP 浓度范围为 0 nM 至 1000 nM 的乙腈-水（V（水）：V（乙腈）=1:1）中孵育，然后转移到相应的空白乙腈-水（pH=0.70）中进行 DPV 测量。随着 BaP 浓度的增加，在 0.98 V（相对于 Ag/AgCl）观察到氧化电流增加，检测限达到 0.67 nM。由于所有其他优先多环芳烃不能在 0.98 V 电化学氧化，该电化学分析方法对 BaP 表现出很高的选择性。最后，该开发的电化学分析方法成功地应用于一系列实际水样，如饮用水、自来水、湖水和河水的 BaP 测定。
