| ObjectiveIn recent years,various pollutants discharged by the pharmaceutical industry,industrial and hospital industries have seriously affected the environmental safety and attracted wide attention.Retinoic acid（RA）,hydrogen peroxide（H2O2）,and acetaminophen（PC）play an important role in treating skin diseases,maintaining normal human physiological function,and treating head heat and headache,respectively.However,the long-term,extensive,and large amount of irrational use of these drug doses may produce a series of side effects.Therefore,it is very important to develop an accurate,sensitive,reliable,and inexpensive detection technology.As an inorganic microporous material,zeolite is widely used in electrochemical analysis because of its special adsorption,catalytic performance,and ion exchange properties due to its unique structure.In this work,LTA zeolite is selected as the substrate to prepare electrochemical sensors and applied to the rapid and simple determination of RA,H2O2,and PC in tap water.MethodsIn this experiment,three kinds of LTA zeolites were synthesized by the hydrothermal method:LTA zeolite,Ti-doped LTA zeolite,and CoO-doped LTA zeolite,and the modified electrodes were prepared,respectively.These materials modified glassy carbon electrodes（GCE）were used for the detection of three drugs（RA,H2O2,and PC）.The reaction mechanism and electrochemical properties of the sensors were studied by cyclic voltammetry（CV）,and the experimental conditions were optimized such as pH value.Drugs were quantified by differential pulse voltammetry（DPV）and square wave voltammetry（SWV）.The stability of the sensors was verified by the chronoamperometry（i-t）.Finally,the sensors were applied to the determination of RA,H2O2,and PC in tap water.ResultsIn this experiment,the electrochemical performance of the three sensors was investigated.First,the electrochemical method for the determination of RA based on the LTA zeolite modified electrode:under optimal conditions,the detection limit（LOD）of RA was 8.0×10-7 mol/L,and the linear range was 8.0×10-7～2.0×10-5 mol/L.This electrochemical method for the determination of RA was simpler and less expensive than previously reported.In addition,the modified electrode was used for the detection of RA in tap water,with a linear range of1.4×10-6～1.5×10-5 mol/L,a LOD of 1.4×10-6 mol/L,and recoveries of 88.2%～101.6%and 92.8%～99.0%.Secondly,by using the Ti-doped LTA zeolite modified electrode,the SWV method was used to accurately detect H2O2,and the linear range of H2O2concentration was 7.8×10-8～1.99×10-5 mol/L and 9.66×10-5～3.85×10-3 mol/L.The Ti LTA/GCE electrode has been successfully applied to the detection of tap water and cell fluid,and the concentration linear ranges were 7.8×10-8～1.99×10-4 mol/L and 1.99×10-4～1.97×10-3 mol/L for tap water and 7.8×10-8～1.49×10-5mol/L for cell fluid.Finally,the DPV quantitative analysis of PC was carried out using CoO-doped LTA zeolite modified electrode.Different concentrations of PC produced two current responses under the modified electrode.The linear ranges were8.0×10-10～2.0×10-7 mol/L and 7.8×10-6～2.16×10-4 mol/L,respectively.The CoO-doped LTA electrode was successfully applied to the determination of PC in tap water,showing two current responses,8.0×10-10～2.0×10-7 mol/L,and8.0×10-6～2.16×10-4 mol/L,respectively.ConclusionsIn this work,LTA zeolite,Ti-doped LTA zeolite,and CoO-doped LTA zeolite were successfully prepared by the hydrothermal method,LTA/GCE,Ti LTA/GCE,and CoO LTA/GCE electrodes were established as sensors for the determination of RA,H2O2,and PC,respectively.The three modified electrodes had good sensitivity and successfully realized the detection of three drugs in real samples.The results showed that the modified electrode designed by this method had good selectivity,stability,and reproducibility for the determination of RA,H2O2,and PC,and provided an experimental basis for the analysis of the three drugs in tap water. |
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