Capillary Electrophoresis With Electrochemiluminescence Detection For The Analysis Of Macrolide Antibiotics

The development of detection method and system with the advantages of rapidity and sensitivity is of great importance for scientific monitoring the security hidden factors and threat existing in the food production process to ensure food safety. Based on the enhancing effects of the studied drugs on the electrochemiluminescence (ECL) of Ru(bpy)32+ and coupled with highly performance capillary electrophoresis (CE) separation, novel analytical methods for different detection purposes were developed to trace macrolide antibiotics in different matrix.Firstly, based on the enhancement effect of the studied three macrolides on the electrochemiluminescence (ECL) of Ru(bpy)32+, coupling with capillary electrophoresis (CE) separation, a simple, rapid and sensitive CE-ECL method was developed to detect azithromycin, roxithromycin and erythromycin ethylsuccinate. And the detection and separation conditions for the studied macrolides were investigated carefully. Under the optimal conditions, the detection limits are 35, 60 and 174 ng/mL, respectively for azithromycin, roxithromycin and erythromycin ethylsuccinate. It has been successfully applied to test the studied three macrolides in spiked biological fluids.Secondly, usingβ-CD as dynamic modifier, a novel CE-ECL method was proposed for the chiral separation and detection of tilmicosin, a novel chiral macrolide antibiotic. All the factors influencing the separation and detection process including electrode potential, separation buffer concentration and pH, detection cell were optimized. Under the selected conditions, the detection limits of 50 ng/mL for cisform and 105 ng/mL for antiform of tilmicosin can be acheived. The proposed method has been successfully applied to detect the drug residue in animal lever.Finally, we found that the gold nanoparticles can effectively sensitized the ECL reactioin between Ru(bpy)32+ and tylosin, spiramycin and josamysin. Based upon the finding, coupling with capillary electrophoresis (CE) separation, a novel method for sensitive detection of tylosin, spiramycin and josamysin were presented. Various factors, such as electrode potential, separation voltage, the injection time and the others, affecting the separation and detection of the three macrolides were investigated to establish the optimal detection system. The detection limit of 23, 6 and 15 ng/mL can be obtained under the optimized conditions, respectively for tylosin, spiramycin and josamysin. The presented method has been successfully applied to test these macrolide antibiotics in the spiked animal lever samples.Samples in the proposed method system can be directly analyzed without derivation requirement, and it offers the merits of simpicity, rapidity and sensitivity, as well as environmental friendly and small sample amount needed.