| Quantum dots, also known as semiconductor nanomaterials, are illumination nano particles and have attracted extensive interest in the past two decades due to their remarkable size-dependent optical and electronic properties. CdS quantum dots, one of the classic semiconductor nanomaterials, have application in the catalysis, the nonlinear optics, the magnetic material, the photoelectron component, the solar energy transform, the domains, the communication, the biology and so on. The process of radiation produced in a chemical reaction from the decay of an excited state to the ground state is known as chemiluminescence (CL). Flow-injection analysis (FIA) is a technology in non-equilibrium thermodynamic conditions which the sample or reagent in the carrier reappearing in the handling zone. Combined with flow injection, chemiluminescence has many features such as high sensitivity, wide linear range, quick analysis, simple and easy to implement automation equipment. Thus has wild application in trace and half trace substance analysis. In this paper CdS quantum dots were added to luminol chemiluminescence system and some phenolic hydroxyl compounds were detected in these system.The main research work has the following aspects:1.?It was found that CdS quantum dots could strong enhance chemiluminescence of luminol-potassium ferricyanide system, thus a new flow injection chemiluminescence method was developed for detection protocatechuic acid. Chemiluminescence photoluminescence spectra and kinetic curves of chemiluminescence were used to investigate the chemiluminescence mechanism. The effect of concentration of luminol, potassium ferricyanide, sodium hydroxide and CdS QDs on chemiluminescence reaction was surveyed respectively. In the optimum conditions,the linear range was 5.0×10-8 1.0×10-5 g/L(r = 0.9986)and the detection limit of the method was 1×10-8g / L, the relative standard deviation was 1.5% (C = 1.0×10-7g / L, n = 11).2. In alkaline conditions, CdS quantum dots could significant enhance the luminol hydrogen peroxide chemiluminescence and the phenol could inhibition the chemiluminescence, thus a new flow injection chemiluminescence method. of detection phenol was set up. Under optimal conditions, the inhibited chemiluminescence intensity was found to be proportional to the concentration of phenol ranging from 5.0×10-9 to 5.0×10-7 g/L(r = 0.9935)and 5.0×10-6 to 1.0×10-3g/L (r = 0.9982), the concentration of detection limit was 2.5×10-9g / L, the RSD was 2.0% for 5.0×10-5 g/L and 0.86% for 5.0×10-8 g/L (n = 11).3. CdS quantum dots had a significant enhancing effect on the potassium permanganate - luminol chemiluminescence system, and thus a new flow injection chemiluminescence method was developed to detecte chlorogenic acid. Under optimal conditions, ,the linear range of testing chlorogenic acid was 1.0×10-9 1.0×10-7 g / L (r = 0.9984). Detection limit was 1.9×10-10 g / L,the RSD was 1.5%(C = 1.0×10-7g / L, n = 11). |
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