The Application Of Electrochemiluminesence By Using Tris (2, 2'-Bipyridine) Ruthenium(â…¡) In Pharmaceutical Analysis

In the paper, the history of electrochemiluminesence (ECL) containing the ECL principles, mechanism of ECL and the application of ECL in pharmaceutical analysis have been reviewed. New methods based on ECL by using tris(2,2′-bipyridine) ruthenium(II) (Ru(bpy)32+) have been developed for the determination of oxytetracycline (OTC), and other tetracycline antibiotics (TCs). Additionally, a new ECL electrode has been prepared for determining important substances such as TPA, epinephrine, and dopamine. The main results are summarized as follows:1. A new flow-injection electrochemiluminescence method has been proposed for the determination of oxytetracycline (OTC). In the 0.1mol/L Na2HPO4–KH2PO4 solution of pH 8.0, the best ECL response was obtained at potential of 1.15 V in the present of 5.0×10?5 mol·L-1 Ru(bpy)32+. The linear range of the method is from 2.50 to 25.0 mg·L-1 with a correlation coefficient of 0.9991 and the detection limit of 2.50 mg·L-1. The method has successfully applied to the determination of OTC in OTC tablets. The relative standard deviation (RSD) was less than 1.50% (n=10) and the recovery percent were from 97.4 ~ 104% for the samples.2. A highly selective and sensitive method based on HPLC?ECL with Ru(bpy)32+ has been developed for the determination of tetracycline antibiotics (TCs). The sample included tetracycline, chlortetracycline, oxytetracycline and doxycycline was separated through HPLC, then they were simultaneously determined by ECL. The XBP-C18 was used as chromatographic column. The eluent was made of pH 8.0 Na2HPO4–KH2PO4 solution, methanol and acetonitrile at the rate 80:15:5. The flow rate and injection volume were chose as 1.0 ml·min-1 and 20μL, respectively. Under the optimized conditions above, four TCs were completely separated and sensitively detected without pre-column deriverization or programmed gradient elution.3. A new ECL electrode was prepared by electrochemical co-polymerization of 2,6-pyridinedicarboxylic acid (PDC) and Ru(bpy)32+ on the surface of Au electrode. The Ru(bpy)32+ were immobilized into the gridded poly-PDC film proportionally. The prepared ECL electrode has sensitive responses to several substances such as TPA, epinephrine and dopamine. Especially, the ECL electrode respond to TPA over the range of 6.5×10-4~1.0×10-6 mol·L-1 with a detection limit of 3.6×10-7 mol·L-1. The ECL electrode displays a good stability in the air under room temperature, being favorable to application in the pharmaceutical and biochemical analysis.