Studies And Applications Of Flow-Injection Chemiluminescence New Systems

Chemiluminescence (CL) is defined as the emission of light from an electronically excited state species which is produced during the course of a chemical reaction, and is observed when the electronically excited product or intermediate formed decays to the ground state with a photon emitted. Due to its high sensitivity, wide linear range, rapidity, simplicity and relatively low cost, chemiluminescence analysis has been widely applied in environmental science and life science and has become one of the most powerful techniques in analytical chemistry.This paper reports the researches and applications of CL analysis in life analysis, environmental analysis. Part I ReviewThis part introduces the history of CL, the mechanism and the detecting principles of CL. Mainly it summarizes the common CL systems and their analytical applications. Part II ReportsBased on potassium permanganate and luminal CL systems combined Flow-Injection analytical method, this paper investigates the effect of ferulic acid, serotonin and some metal ions on luminescence reaction, and simultaneously these matters have been detected in real samples, and the experimental mechanism have initially been discussed. Moreover, the new combination of the ultrasonic technique and FIA-CL method has been searched.2.1 Permanganate-based Chemiluminescence Analysis of Ferulic Acid Using Flow InjectionA simple, sensitive and rapid flow injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with potassium permanganate in nitric acid medium. Strong chemiluminescence signal was observed when ferulic acid was injected into the acidic potassium permanganate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 6.0×l0^-6 to 2.0×10^-4mol l^-1 and the detection limit (3σ) for ferulic acid was 9.6×10^-8 mol l^-1 . The relative standard deviation was 1.0 % for 11 replicate analyses of 2.0×10^-4 mol l^-1 ferulic acid. The proposed method was appliedto the determination of ferulic acid in Taita Beauty Essence samples with satisfactory results. Moreover, the reaction mechanism of the chemiluminescence system has been primarily discussed.2.2 Second Chemiluminescence Behavior of Some Metal Ions in the Luminal-KMnO4 SystemA novel flow injection chemiluminescence (CL) method has been developed for the determination of three metal ions, namely Ni2+, Fe2^, Fe3" and Cr3^, based on the second CL (SCL) signal of the mixture of luminal with KMnO4 in sodium hydroxide medium by the catalysis of Ni"+, Fe +, Fe3" and Cr3". The possible CL mechanism of the systems, the influencing factors, and the optimum conditions for the reactions have been investigated based upon the kinetic curve of the CL reaction, CL spectra, UV-visible spectra and some other experiments. Under optimum conditions the SCL intensity was directly proportional to the concentration of these metal ions in solution in the range of 8.0-200.0 (ig 1 and 0.2-2.0 mg I"1 for Ni2\ 0.10 - 100.00 mg I"1 for Fe2", 0.50-7.50 and 7.51-200.00 mg I"' for Fe3", 0.01-0.25 and 0.25-10.00 mg I"1 for Crv. the detection limit (3 a/s) were 3.3x 10^?g T1, 9.87 x 10"6g F1, 2.71 x 10'6gl"' and 5.25 x 10⁷ g 1^'for Ni2', Fe2\ Fe3 and Cr3^, respectively.2.3 Ultrasonic-Flow Injection-Chemiluminescence TechniqueWhen the reagents were incurred to the ultrasonic and then were injected into the cell, the CL signal compared with the former had great change. Based on this, it has been investigated that the effect of the ultrasonic time and the ultrasonic frequency, and the ultrasonic of the different reactants on the system. And the possible CL mechanism is proposed based on the kinetic curve of the CL reaction, CL spectra, U V-vis spectra and some other experiments.*2.4. Determination of Serotonin Using Flow-injection Inhibitory ChemiluminescenceA new flow-injection chemiluminescence method for the quantitation of serotonin has been developed basing on the strongly restraining effect of serotonin on the chemiluminescence reaction between luminal and potassium hexacyanoferrate(lil) in alkali medium. The optimization of the experimental and instrumental variables such as, concentration of reagents, flow rates, the length of mixing tube, the acidity of sample, etc., has been carried out adopting the proposed flow-injection manifold. The performance characteristics have been established, showing a linear response in the range of 4.0 to 20 uM, a detection limit (3a) 1.58 * 10"8 mol 1"' and a 1.0 % relative standard deviation for 11 replicate analyses of 10 uM serotonin. The proposed method was applied to the determination of serotonin in synthesis samples with satisfactory results. Moreover, the reaction mechanism of the chemiluminescence system has been primarily discussed.