Study On Drugs Using Electrochemiluminescence Sensors Coupled With Capillary Electrophoresis

Capillary electrophoresis-elecreochemiluminescence（CE-ECL）combines the advantages of high separation efficiency,short analysis time and minimal sample volume of CE and high sensitivity,wide linear range of ECL.CE-ECL,as a powerful analytical technique,has been widely used in various fields such as pharmaceutical analysis,biological analysis and environmental analysis.CE-ECL application in pharmaceutical analysis is a complement to the traditional analysis methods,which provides a sensitivity analysis method to pharmaceutical analysis.Improving the sensitivity of CE-ECL by chemical modified electrode which gives the electrode a special function.The aim of this work is to expand the application of the Ru（bpy）₃²⁺-based CE-ECL technique and improve the sensitivity of CE-ECL by chemical modified electrode.The main contents and results were introduced as follows:1.A new method was developed to study the interaction between human serum albumin（HAS）and buflomedil hydrochloride（BUF）and verapamil hydrochloride（VER）using ultrasonic mirodialysis（USMD）coupled with CE-ECL.The equilibrium time for BUF-HAS and VER-HAS was 40 and 50 min using ultrasonic,which was far less than that of traditional dialysis（140 min and 160 min）,respectively.It took 240 min and 150 min for BUF-HAS and VER-HAS to achieve the equilibrium by traditional dialysis and only 60 min and 50 min using ultrasonic microdialysis.Compared with traditional dialysis,the use of ultrasonic microdialysis greatly shortened experimental time.Both the equilibrium time and dialysis time are shortened by more than 3 times.The number of binding sites of BUF and VER with HAS are 0.568 and 0.513,respectively.The binding constants of BUF and VER are 0.65×10⁴ and 0.44×10⁴ L/mol,respectively.2.In this study,we used a simple solvothermal method to synthesize the composite of silver nano paricles（AgNPs）and nitrogen-sulfur codoped graphene（NS-G）.Based on the enhancement of Ru（bpy）₃²⁺by AgNPs/NS-G modified electrode,a new method for the simultaneous determination of propranolol hydrochloride（PRO）and cetirizine Hydrochloride（CTZ）has been developed using capillary electrophoresis-chemical modified electrode-electrochemiluminescence.The parameters including detection potential,the concentration and the pH of phosphate buffer,and the separation voltage that affect separation and detection were optimized.Under the optimum conditions,the linear ranges were between 0.001 and 2 μg/mL for propranolol hydrochloride with a correlation coefficient of 0.9985,and between 0.005 and 2 μg/mL for cetirizine hydrochloride with a correlation coefficient of 0.9956.Detection limits of propranolol hydrochloride and cetirizine Hydrochloride were 0.35 and 1.8 ng/mL（S/N=3）,respectively.This method was successfully applied to detect propranolol hydrochloride and cetirizine hydrochloride in mice plasma.The recoveries were between 95.65%and 97.90%.RSDs were less than 4%.3.This work reports a new electrochemiluminescence detection strategy based on Ru（bpy）₃²⁺/Nafion/Boron-phosphorus codoped graphene（BP-G）composite films modified glassy carbon electrode（GCE）.Based on the enhancement of Ru（bpy）₃²⁺by BP-G modified electrode,a new method has been established for the simultaneous determination of prazosin hydrochloride（PRH）and benazepril hydrochloride（BH）using capillary electrophoresis-chemical modified electrode-electrochemiluminescence.The effects of detection potential,the concentration and the pH of phosphate buffer on ECL intensities were investigated.Under the optimum conditions,the linear ranges were between 0.004 and 2 μg/mL for prazosin hydrochloride with a correlation coefficient of 0.9986,and between 0.005 and 2 μg/mL for benazepril hydrochloride with a correlation coefficient of 0.9995.Detection limits of prazosin hydrochloride and benazepril hydrochloride were 1.6 and 1.8 ng/mL（S/N=3）,respectively.This method has been successfully applied for the detection of prazosin hydrochloride and benazepril hydrochloride in mice plasma.The recoveries were from 95.90%to 98.70%and RSDs were less than 4%.