| Chemically modified carbon paste electrode was prepared by different modifier,which had different effects in the determination of metal ions,It was prepared by identical modifier,but with different material ratio,which also had different effects.The study discussed preparation methods of graphene oxide,EDTA and graphene oxide/EDTA modified carbon paste electrode.Chemically modified carbon paste electrodes had been prepared by above mention preparation methods,through the cyclic voltammetry method detect of copper ions in solution.Experimental results showed that the determination of copper ions by graphene oxide/EDTA modified carbon paste electrode was the best.Part?:We studied a new discussion of graphene oxide based on Hummers method in detail,which had prepared Graphite oxide modified carbon paste electrode.This method shortened the experimental period and reduced the reagent dosage.These samples havd been characterized by SEM and EDS.Graphene oxide modified carbon paste electrode had been prepared,The peak current and the concentration of copper ions showed linear relationship in the range of 4.0×10-8 mol/L1.0×10-3 mol/L and the detection limit is 4.559×10-8 mol/L,which the experimental conditions were optimized.Graphene oxide modified carbon paste electrode shows good reproducibility and stability.Part?:The EDTA modified carbon paste electrode has been prepared based copper ions in the electrolytic liquid can enriched on the modified electrode surface,copper ions and EDTA can formed complex compound.When the material ratio of graphite and EDTA was 4:1,the p H value was 3.2,scan rate was 120 mV/s,the experimental conditions were optimized.The peak current and the concentration of copper ions showed linear relationship in the range of 3.0×10-8 mol/L1.0×10-3 mol/L.The detection limit was 4.745×10-8 mol/L.It has simple operation and good results.Part?:The determination of copper ions by graphene oxide/EDTA modified carbon paste electrode was better than other ones.Studying the impact of these factors:the pH value,the proportion of modifier,scanning speed and range.When the material ratio of graphite and EDTA and graphene oxide was 6:2:2,the pH value was 3.0,scan rate was 120 m V/s,the experimental conditions were optimized.The characteristic peaks and the concentration of copper ions showed linear relationship in the range of 1×10-9 mol/L1.0×10-3 mol/L,the detection limit was 3.833×10-9 mol/L,fast response and efficient.Graphene oxide/EDTA modified carbon paste electrode shows good reproducibility and stability.This modified carbon paste electrode is easily prepared and low-cost,highly sensitive,has high value for practical application. |
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