基于多壁碳纳米管和聚十六烷基三甲基溴化铵修饰玻碳电极的电化学法快速测定水和土壤中双酚A的含量  

Rapid Determination of Bisphenol A in Water and Soil by Electrochemical Method Based on Glassy Carbon Electrode Modified with Multi-Walled Carbon Nanotubes and Poly Cetyl Trimethyl Ammonium Bromide

作　　者：李丹莹 黄象金 韦寿莲[3] LI Danying;HUANG Xiangjin;WEI Shoulian(Department of Enviromental Protection and Testing,Guangdong Urban Technician College,Guangzhou510520,China;Zhaoqing Institute for Food Control,Zhaoqing526060,China;Guangdong Provincial Key Laboratory of Environmental Health and Resource Utilization,Zhaoqing University,Zhaoqing526061,China)

机构地区：[1]广东省城市技师学院环保与检测学院,广州510520 [2]肇庆市食品检验所,肇庆526060 [3]肇庆学院广东省环境健康与资源利用重点实验室,肇庆526061

出　　处：《理化检验（化学分册）》2022年第7期803-810,共8页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：肇庆市科技创新指导类项目(202004031501);广东省市场监督管理局科技计划项目(2020CS11)。

摘　　要：基于多壁碳纳米管(MWCNTs)和聚十六烷基三甲基溴化铵(p-CTAB)的高导电性、高增敏性,制备了MWCNTs、p-CTAB修饰的玻碳电极(GCE),将其作为工作电极(MWCNTs/p-CTAB/GCE),用于快速测定水和土壤中双酚A(BPA)的含量。以GCE为工作电极,采用循环伏安法(CV)对0.5 g·L^(-1) CTAB溶液扫描20圈,得到p-CTAB修饰的GCE(p-CTAB/GCE);吸取1.96 g·L^(-1) MWCNTs标准溶液5μL,滴涂在p-CTAB/GCE表面,干燥后得到MWCNTs/p-CTAB/GCE。水样经过滤,分取2 mL与0.3 mol·L^(-1)磷酸盐缓冲溶液(pH 7.0)8 mL混匀后待测;土壤样品25 g经风干、研磨、过筛后,用乙醇50 mL提取两次,浓缩至约1 mL,用无水乙醇定容至10 mL,分取2 mL与0.3 mol·L^(-1)磷酸盐缓冲溶液(pH 7.0)8 mL混匀后待测。以MWCNTs/p-CTAB/GCE为工作电极,钛棒为对电极,饱和甘汞电极为参比电极,设置搅拌速率为800 r·min^(-1),于0.2 V富集待测样品溶液中的BPA 150 s,采用差分脉冲伏安法(DPV)测定BPA的含量。扫描电子显微镜表征结果显示,MWCNTs/p-CTAB/GCE表面呈多孔空隙和多孔网状结构。以DPV、CV和电化学阻抗谱法考察了BPA在MWCNTs/p-CTAB/GCE上的电化学行为,结果表明BPA在该电极上的电化学氧化反应是一个受吸附控制的不可逆反应,BPA的浓度在0.08~20μmol·L^(-1)内与其对应的氧化峰电流呈线性关系,检出限为0.02μmol·L^(-1)。用同一支MWCNTs/p-CTAB/GCE重复测定BPA标准溶液10次,测定值的相对标准偏差为5.0%。对实际样品进行加标回收试验,BPA的回收率为82.0%~106%,测定值的相对标准偏差(n=5)为1.6%~8.1%。Based on high conductivity and high sensitivity of multi-walled carbon nanotubes(MWCNTs)and poly cetyl trimethyl ammonium bromide(p-CTAB),the glassy carbon electrode(GCE)modified with MWCNTs and p-CTAB was prepared and used as working electrode(MWCNTs/p-CTAB/GCE)for the rapid determination of bisphenol A(BPA)in water and soil.GCE modified with p-CTAB(p-CTAB/GCE)was obtained by scanning 0.5 g·L^(-1) CTAB solution for 20 cycles by cyclic voltammetry(CV)with GCE as working electrode.5μL of 1.96 g·L^(-1) MWCNTs standard solution was dropped on the surface of p-CTAB/GCE,and MWCNTs/p-CTAB/GCE was obtained after drying.Water sample was filtered,and 2 mL of an aliquot was mixed with 8 mL of 0.3 mol·L^(-1) phosphate buffer(pH 7.0)for test.After drying,grinding and screening,25 g of soil sample was extracted with 50 mL of ethanol for twice,concentrated to about 1 mL,and made its volume up to 10 mL with ethanol.2 mL of an aliquot was mixed with 8 mL of 0.3 mol·L^(-1) phosphate buffer(pH 7.0)for test.Using MWCNTs/p-CTAB/GCE as the working electrode,titanium rod as the counter electrode and saturated calomel electrode as the reference electrode,BPA in the test solution was enriched at 0.2 V for 150 s with stirring rate of 800 r·min^(-1),and determined by differential pulse voltammetry(DPV).The surface of MWCNTs/p-CTAB/GCE showed porous voids and porous network structures by scanning electron microscope characterization.The electrochemical behavior of BPA on MWCNTs/p-CTAB/GCE was investigated by DPV,CV and electrochemical impedance spectroscopy.The results showed that the electrochemical oxidation of BPA on MWCNTs/p-CTAB/GCE was irreversible and controlled by adsorption,and linear relationship between concentration of BPA and its oxidation peak current was kept in the range of 0.08-20μmol·L^(-1),with detection limit of 0.02μmol·L^(-1).The BPA standard solution was determined by the same MWCNTs/p-CTAB GCE for 10 times,with RSDs of the determined values of 5.0%.Test for recovery was made on the actual samples by standa

关 键 词：双酚A 多壁碳纳米管 聚十六烷基三甲基溴化铵 电化学法 

分 类 号：O657.1[理学—分析化学]