Simultaneous Detection Of Cd(?) And Pb(?)by Carbonized ZIF-8/Bi Modified Electrode

The pollution of toxic and non degradable heavy metal ions in wa ter has become increasingly serious,causing great harm to human health and ecosystem.It is of great significance to establish a rapid,convenient and accurate detection method for heavy metal ions in order to protect human health and maintain ecosystem balance.Electrochemical method has the advantages of high sensitivity and easy operation,which make it widely used in the detection of heavy metal ions.This paper employs electrochemical methods to detect cadmium ions and lead ions.The contents are as below.Bismuth film and antimony film modified screen printed electrodes were prepared to detect cadmium and lead ions with square wave anodic stripping voltammetry,respectively.The detection parameters such as deposition voltage and deposition time were optimized.Under the optimal experimental conditions,20 ?g/L cadmium and lead ions can be detected,respectively.However,the linear relationship between the peak current and the concentration of cadmium/lead ions was not yet obtained.The carbonized ZIF-8/Bi/GCE was prepared by modifying the bismuth film and the carbonized ZIF-8 on the surface of the glassy carbon electrode for heavy metal ion detection.The experimental conditions were optimized.Under the optimal detection conditions,the peak current value showed a good linear relationship with the cadmium ion concentrations and the lead ion concentrations.The response calibration curves were obtained.During separate detection of each ion,the linear range of cadmium ions is 5?50 ?g/L with the detection limit of 1.39 ?g/L,while the linear range of lead ions is 10?50 ?g/L with the detection limit of 3.52 ?g/L.When detecting cadmium ions and lead ions simutaneously,the linear range was 10?50 ?g/L with the detection limits to be 1.57 ?g/L and 5.65 ?g/L,respectively,which satisfy the national standard.The reproducibility of carbonized ZIF-8/Bi/GCE was studied.The standard deviation of cadmium ion and lead ion was 7.3% and 4.7% respectively,which showed that the method was suitable for the detection of cadmium ion and lead ion.