Enhancement in Chemiluminescence by β-Cyclodextrin for the Oxidation of Luminol by Hypochlorite and Its Applications
Date Issued
2004
Date
2004
Author(s)
Chen, Yu-Cheng
DOI
zh-TW
Abstract
We have studied the enhancement in chemiluminescence (CL) for the oxidation of luminol with hypochlorite caused by β-cyclodextrin (β-CD) using a home-made flow injection analysis system. A 20-fold increase in CL intensity was observed upon addition of 5 mM β-CD to the CL system at pH 9.5. The CL-enhancement may result from the increases in the overall CL efficiency and the fluorescence quantum yield from the stabilization of the CL intermediate(s) and/or product in the interior of the inclusion complex with β-CD. The effects of pH, flow rate, concentrations of reagents (luminol, β-CD, hypochlorite), and modes of reagent mixing on CL emission were also investigated and optimized. The CL system has been applied to the determination of antioxidants such as curcumin, hydroquinone etc. The antioxidants destroy the radicals involved in the CL reaction, causing a decrease in CL emission. The linear dynamic ranges vary for different antioxidants with different antioxidative power. The CL method is useful for the detection of compounds that have no chromophoric groups. Inhibition of CL emission allows the determined of most amino acids at 0.1-1 mM. On the other hand, cysteine and methionine can be determined over the concentrations of 1-10 μM without significant interferences from other amino acids. The lack of selectivity requires a chromatographic column prior to the CL detection.
Subjects
次氯酸
β-環糊精
化學發光
chemiluminescence
luminol
β-cyclodextrin
hypochlorite
Type
thesis
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