Determination Of β-blockers And Macrolide Antibiotics By Capillary Electrophoresis With Electrochemiluminescence Detection

Capillary electrophoresis is a highly efficient means of separation, which is performed in capillary tube and driven by electric field.1. A CE with ECL detection using polyvinylpyrolidone as additive was developed for the simultaneous separation and determination of atenolol, esmolol, and bisoprolol. The sensitivity of three drugs can be increased greatly by field-amplified sample stacking. Under the optimal conditions, the LOD (S/N=3) of atenolol, esmolol, and bisoprolol are3.4x10-9,3.5x10-9, and2.2x10-9mol/L, respectively. The precisions (%) of the peak area and migration times were in the range of2.2to3.7and0.4to0.8within a day and3.1to5.5and3.9to4.5in three days. The LOQ (S/N=10) of three β-blockers are7.7x10-8,8.6x10-8, and6.7x10-8mol/L in human urine, and1.110-7,1.4x10-7, and9.1x10-8mol/L in human serum. The recoveries of three analytes at different concentration levels in human urine and serum samples were between86.2%and103.7%. The proposed method was successfully applied to the determination of three analytes in human urine and human serum. The number of binding site and the binding constant of HSA and esmolol were also estimated by this method.2. A sensitive method for the simultaneous determination of azithromycin (AZI), tilmicosin (TIL), acetylspiramycin (ACE), and roxithromycin (ROX) has been established using CE coupled with ECL detection. The use of ionic liquid (IL) significantly improved separation efficiency and detection sensitivity. The conditions for CE separation and ECL detection were investigated in detail. Under the optimal conditions, the four macrolides were well separated and detected within7min. LOD of AZI, TIL, ACE, and ROX were1.3x10-9,2.5x10-9,2.3x10-8, and7.0x10-8mol/L, respectively. The precisions of the peak area and migration times were from1.1to4.9%and from1.3to2.4%within a day and from3.3to6.0%and from2.4to4.8%in three days. LOQ in human urine for AZI, TIL, ACE, and ROX were9.310-8,1.2x10-7,7.6x10-7, and2.1x10-6mol/L, respectively. The recoveries of the four analytes at different concentration levels, found in human urine, drug, pig fodder, and egg samples were between87.4-107.9%with RSD ranging from1.0to7.2%. The developed method has been successfully applied to the determination of AZI, TIL, ACE, and ROX in human urine, tablets, pig fodder, and egg samples.