Flow-injection Electrochemilu-Minescence Analytsis Based On The Enzymatic Reaction

In this paper, the history and application of electrochemiluminesence (ECL) havebeen reviewed. The main system on ECL, their reaction principles, and the combinedtechniques of ECL with other analytical methods have been introduced. Asluminescent reagent, the ECL principle and application of luminol, and variousmethods on immobilizing enzyme have been reviewed. Based on the preparation ofmicro-column enzyme reactor, new flow-injection ECL methods have been developedfor the determination of guanine, thioguanine, acyclovir, and cholesterol. The mainresults are summarized as follows:1. Based on the enzymatic reaction of guanine and thioguanine by xanthine oxidaseimmobilized in a micro-column, two flow-injection ECL methods have been developedfor the determination of guanine and thioguanine. When the sample flows through theenzyme reactor, the xanthine oxidase catalyzes guanine and thioguanine to producehydrogen peroxide (H2O2). Followed by ECL reaction of H2O2with luminol, theguanine and thioguanine were determined in the sample. In the paper, effects of themobile phase, electrolyte pH, excitation potential, and luminol concentration on theECL intensity were investigated and optimized. The linear response of guanineconcentrations ranged from4.53×10-2to10.6μg/mL was obtained with a detection limitof2.0×10-3μg/mL. The linear response of thioguanine concentrations ranged from0.50μg/mL to32.3μg/mL was obtained with a detection limit of0.12μg/mL. The presentedmethods were successfully applied to detect the active ingredient of guanine andthioguanine in pharmaceutical preparations. The relative standard deviation was lessthan1.60%(n=9) and the recovery was in the range of97.8%~107%for thedetermination of actual thioguanine samples.2. Based on the enzymatic reaction of aciclovir by xanthine oxidase immobilized in amicro-column, a flow-injection ECL method has been developed for the determinationof aciclovir. When the sample flows through the enzyme reactor, the xanthine oxidasecatalyzes aciclovir to produce hydrogen peroxide (H2O2). Followed by ECL reaction of H2O2with luminol, the acyclovir was determined in the sample. In the paper, effects ofthe mobile phase, electrolyte pH, excitation potential, and luminol concentration on theECL intensity were investigated and optimized. The linear response of aciclovirconcentrations ranged from0.56to22.5μg/mL was obtained with a detection limit of0.32μg/mL. This method was successfully applied to detect the active ingredient ofacyclovir in pharmaceutical preparations. The relative standard deviation was less than1.80%(n=9) and the recovery was in the range of95.5%~108%for the determinationof actual samples.3. A new flow-injection ECL method has been developed for the determination ofcholesterol based on the enzymatic reaction of cholesterol by cholesterol oxidaseimmobilized in a micro-column. When the sample flows through the enzyme reactor,the cholesterol oxidase catalyzes cholesterol to produce hydrogen peroxide (H2O2).Followed by ECL reaction of H2O2with luminol, the cholesterol was determined in thesample. In the paper, effects of the mobile phase, electrolyte pH, excitation potential,and luminol concentration on the ECL intensity were investigated and optimized. Thelinear response of cholesterol concentrations ranged from8.00×10-2μg/mL to19.3μg/mL was obtained with a detection limit of3.80×10-3μg/mL. This method wassuccessfully applied to detect the active ingredient of cholesterol in pharmaceuticalpreparations. The relative standard deviation was less than1.42%(n=9) and therecovery was in the range of99.1%~107.1%for the determination of actual samples.