可再生电化学传感器同步检测贝类中痕量铅和镉

A Reusable Electrochemical Sensor for Simultaneous Determination of Trace Lead and Cadmium in Shellfish

目的:针对贝类中高毒重金属铅(Pb)和镉(Cd),开发一种可再生、廉价、快速、灵敏的电化学传感器。方法:以自制离子液体/石墨烯电极(IL/GNs HME)为工作电极,采用微分脉冲阳极溶出伏安法(DPASV)原位镀铋,根据得到的溶出峰电流,实现对Pb^(2+)和Cd^(2+)的同步测定。结果:在铋离子质量浓度500μg/L,富集时间420 s,搅拌速度600 r/min,富集电压-1.1 V,缓冲体系HAc-Na Ac p H 4.2的条件下,利用电化学传感器测得的Pb^(2+)和Cd^(2+)的线性范围均为1.0~45.0μg/L,检测限分别达0.5μg/L和0.8μg/L。采用IL/GNs HME电化学传感器同时检测扇贝、褶牡蛎、长竹蛏、菲律宾蛤子中Pb^(2+)、Cd^(2+)含量时,所得结果均与电感耦合等离子体质谱(ICP-MS)检测结果相符。结论:基于IL/GNs HME构建的电化学传感器操作简便、灵敏度高,可实现对贝类中Pb^(2+)、Cd^(2+)含量的快速、同步测定。

Lead(Pb)and Cadmium(Cd)have emerged as major mussel pollutants in recent decades,thus the development of sensors capable of detecting both of Pb and Cd is of considerable interest.In this work,a bismuth film modified homemade electrode(HME)composed of ionic liquid/graphene composite(IL/GNs)was used as a working electrode for simultaneous detection of trace Pb^(2+)and Cd^(2+)in shellfish by differential pulse anodic stripping voltammetry(DPASV).The best experimental parameters were optimized and set as follows:the mass concentration of Bi3+at 500μg/L,the enrich time of 420 s,enrich voltage at-1.1 V,stirring speed of 600 r/min,and HAc-Na Ac buffer p H at 4.2.Under the optimal conditions,the DPASV peak currents showed good linear relationships with the mass concentrations of Pb^(2+)and Cd^(2+)in the same range of 1.0~45.0μg/L and the detection limits for Pb^(2+)and Cd^(2+)were 0.5μg/L and 0.8μg/L,respectively.The analysis system was successfully applied to simultaneous detection of Pb^(2+)and Cd^(2+)contents in Scallop,Ostrea plicatula,Solen gouldi,Ruditapes philippinarum,and the results were comparable with those obtained from ICP-MS.The electrochemical sensor based on IL/GNS HME is easy to be operated and has high sensitivity toward sensing Pb^(2+)and Cd^(2+).It can be used for the rapid,accurate,and simultaneous detection of trace Pb^(2+)and Cd^(2+)in shellfish.