| Chemiluminescence (CL) can be defined as the characteristic emission of radiation from a molecule, atom or effective fiuorophore, in an excited electronic state, produced in an exothermic chemical reaction. It can take place in the gas, liquid and solid phase. In recent years, CL has become a powerful analytical tool for selective and sensitive detection of chemical species. CL applications in analytical chemistry have numerous advantages such as high sensitivity, a wide linear range, simple and inexpensive instrumentation, and considerable reduction of the background noise. There are numerous reports supporting the importance of chemiluminescent methods in analytical chemistry, including a great variety of fields such as food, biomedical, anyway as detection system.Electrogenerated chemiluminescence (ECL), know as electrochemilumicescence, which combines chemiluminescence (CL) and electrochemistry. The CL reaction was initiated by an electrochemical reaction at electrode surface. Such an electro-initiation reaction introduces a large number of additional advantages, such as high sensitivity and selectivity, rapid and convenient operation and relatively simple instrumentation system. So ECL is becoming more and more important in many fields.Flow-injection chemiluminescence (FI-CL), which combines chemiluminescence (CL) and flow-injection, has high efficiency and accuracy. It becomes more and more important in pharmaceutic analysis. The dissertation is composed of three chapters as followings:Chapter 1: Introduced the ECL and its application in analytical chemistry field, paid more attention to the types of ECL reaction and ECL sensors. Introduced the FI-CL and its application in pharmaceutic analysis. At last pointed out the purpose of the dissertation.Chapter 2: Determination of Co2+ based on the cobalt( It )-catalyzed electrochemiluminescence of luminol in acidic solutionThe catalytic reaction of cobalt(II) to Luminol and hydrogen peroxide was investigated, the electrochemical behavior of luminol in weakly acidic solution was studied. It is found that Co + remarkably enhances the electrochemiluminescence (ECL) of luminol in citric acid-sodium citrate buffer solution (pH=4.0) when a pulse potential (-1.8-+1.0 V, vs. Ag/AgCl) is applied to the Pt electrode. The selectivity for Co2+ is very good because most of the other water soluble metal ions do not interfere. A sensitive and selective ECL method for determination of Co2+ is proposed. After optimization of the reaction conditions and electrochemical parameters influencing the relative ECL intensity, the linear range responding to Co2+ is 5.0xl0-12-1.0xl0'7 mol/L, and the detection limit is 2.0> |
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