Determination Of Amine Compounds By Electrochemiluminescence Method

In the paper, the history of electrochemiluminesence (ECL) containing the principles, main reaction systems and mechanism of ECL and the application of ECL in pharmaceutical analytical field were reviewed. New methods based on ECL have been developed for determining ephedrine hydrochloride, diphenhydramine and penicillin-like antibiotics. Some chief results were shown as following:1. A new flow-injection electrochemiluminescence (FIA-ECL) analytical method of ephedrine hydrochloride has been proposed in this paper. It is based on a fact that ephedrine could react with tris(2,2′-bipyridine)ruthenium(II)(Ru(bpy)32+) to enhance electrochemiluminescence signal. In the Na2B4O7-NaOH solution of pH10.0, The best ECL response was obtained at potential of 1.10 V in the present of 1.0×10-4 mol/L Ru(bpy)32+ The linear range of the method is from 2.40 to 24.0 mg/L with a correlation coefficient of 0.9995 and the detection limit of 2.00 mg/L. The method has successfully applied to the determination of ephedrine hydrochloride in ephedrine injection and nasal drop. The relative standard deviation (RSD) was less than 1.60% (n=10) and recoveries were from 96.0% to 103% for the determination of practical samples.2. On the basis of the structural effect between diphenhydramine hydrochloride (DPH) and ephedrine hydrochloride (EPH) to enhance ECL intensity, FIA-ECL analysis of DPH in the present of EPH by utilizing Ru(bpy)32+. In the experimental conditions optimized, the linear ECL response to concentrations of DPH is from 2.00 to 40.0μg/L with a correlation coefficient of 0.9995 and a detection limit of 1.20μg/L. RSD was less than 4.6% (n=5) and recoveries were in the range of 98.0-106% for the determination of DPH in pharmaceutical samples. The method avoids triumphantly an interference of coexistent EPH in the compounding drug without prior separation. The method has advantages over HPLC method in terms of speed and convenience, economics and safe procedure, and could be an alternative for places where HPLC equipment is not available.3. A highly selective and sensitive detection method of Penicillin-like antibiotics based on HPLC?ECL with Ru(bpy)32+ has been developed. The ECL emission is based on the reaction between the hydrolysis of Penicillin-like antibiotics and Ru(bpy)33+. The experimental results showed that maximum ECL intensities are obtained after hydrolyzing 30 min, because ECL on the Penicillin-like antibiotics were strongly dependent on the hydrolysis time. Under the optimal condition, the linear detection range from 1.0 to100.0μg/mL and the detection limits are estimate to 0.1μg/mL with S/N of 3 for four Penicillin-like antibiotics. The RSDs is less than 6.0% (n=10) and recoveries were in the range of 96.3%-105.3% for the determination of four Penicillin-like antibiotics in human urine samples. The results are satisfactory compared with HPLC method.