A New Chemiluminescence Method And Its Application In The Detection Of Phenolic Compounds

Phenolic compounds are a kind of toxic pollutants,which can cause cumulative chronic poisoning through the skin mucosa,respiratory tract and digestive tract to enter the human body.Inhalation of high concentrations of phenols can cause acute poisoning and even death.Therefore,the detection of phenolic substances in water samples is of great significance to the living environment and human health.However,traditional detection techniques such as high performance liquid chromatography?HPCL?and gas chromatography have the disadvantages of being expensive and difficult to operate.At present,the development of new analytical techniques to detect phenolic compounds has become a focus in the analytical field.Chemiluminescence?CL?is a phenomenon in which the substance in the reaction system absorbs the energy released by the chemical reaction to an unstable excited state,and then returns to the ground state to generate light emission without the action of an external light source or other energy.CL is a dark field technology without light source and complex optical system,which can eliminate the influence of scattered light,reduce background signal and improve the signal-to-noise ratio of instrumental analysis.Therefore,it has high sensitivity and wide linear range,as well as the advantages of simple equipment,low price and easy miniaturization.However,traditional CL systems have developed slowly in recent years.At present,nanomaterials have become a research hotspot due to their unique optical properties,and nanomaterials-based chemiluminescence has become more and more in-depth.Especially,quantum dots?QDs?have the advantages of size effect,high fluorescence efficiency,wide excitation wavelength,etc.It can act as catalysts,illuminants,energy acceptors in the field of CL,which can significantly improve enhance the luminescence intensity of the system to meet the actual detection requirements.QDs-based CL system has been favored by the majority of CL analysts.However,the outstanding shortcoming of CL analysis is the poor selectivity,which is not suitable for analyzing complex samples and simultaneously detecting multiple analytes,thus limiting its application.In order to solve this problem,various works and literatures have reported methods of combining CL with molecular imprinting,immunoassay,microfluidic chip,capillary electrophoresis,HPLC,etc..The most common of which is combined with liquid chromatography.With the HPLC,post column chemiluminescence detection can be used to analyze sensitively a variety of substances in complex samples.In this paper,the successful construction of a new CL method based on the participation of quantum dots and HPLC not only broadens the application scope of CL analysis,but also has a very important theoretical value and significance for the further development of a new CL system.This paper is divided into two parts:the first part is a literature review,which briefly summarizes the harm and detection method of phenolic compounds,The research status of nanomaterials in chemiluminescence systems and the application of other techniques?such as high performance liquid chromatography?in combination with chemiluminescence analysis.The second part is the research report.In this paper,based on the participation of cadmium telluride quantum dots and HPLC,a new simple method for the quantitative detection of phenolic compounds in environmental water samples is constructed.The research report is including the following three parts:1 A novel chemiluminescence resonance energy transfer system based on bis?2,4,6-Trichlorophyenyl?oxalate and hydrogen peroxide induced by CdTe QDs for determination of phloroglucinolGlutathione-coated cadmium telluride quantum dots?GSH-CdTe QDs?were synthesized with reference to previous literature,which replaced traditional fluorescent dyes and enhanced CL reaction between bis-?2,4,6-trichlorophenyl?oxalate?TCPO?and H₂O₂ as a new luminophore.According to the results of kinetic analysis,CL spectrum,UV-vis and fluorescence spectrum,the possible mechanism of CL reaction was proposed.The intermediate?1,2-dioxadienedione?produced by the TCPO-H₂O₂ reaction acts as a donor to transfer energy to the acceptor CdTe QDs,and QDs act as luminophor to generate higher-intensity CL signals.With the addition of phloroglucinol solution,the luminescence intensity of the system significantly decreased.Based on this,the method of sensitizing TCPO-H₂O₂ CL system by CdTe QDs was established to determine the phloroglucinol in the water sample.2 Detection of catechol in water based on cadmium telluride quantum dot enhanced fluorescein-potassium periodate ultra-weak chemiluminescence systemThere was an ultra-low CL phenomenon between fluorescein and potassium periodate?KIO₄?in alkaline media.The CdTe QDs synthesized by the reference can significantly improve the luminescence intensity of the system.This paper reports for the first time that CdTe quantum dots are applied to the fluorescein-KIO₄ CL system.It was found that catechol inhibited the CL signal of the system.Under the optimal experimental conditions,the CL intensity decreased linearly within the concentration range of catechol from 1 to 100?mol·L^-1,and the detection limit of catechol was 0.18?mol·L^-1.According to the kinetic analysis results,the CL spectra,UV-vis and fluorescence spectra suggest possible reaction mechanism.Finally,the CL method was successfully applied to the determination of catechol in environmental water samples.3 Application of Luminol-copper sulfate chemiluminescence system with high performance liquid chromatography to simultaneously determinate of tert-butyl hydroquinone and hydroquinoneThe antioxidants tert-butyl hydroquinone?TBHQ?and hydroquinone?HQ?were quantitatively analyzed by HPLC-CL.In the experiment,methanol and water?70:30?were used as mobile phases to separate the C18 column and post-column CL detection,the influencing factors in the system were optimized.In the optimal experimental environment,the linear range of TBHQ was 0.6-120?mol·L^-1,and the detection limit was estimated to be 0.072?mol·L^-1.CL intensity decreased linearly in a 0.9 to 180?mol·L^-11 HQ concentration range,with a 0.17?mol·L^-11 detection limit.The obtained percentage recoveries in the range of 98.5%-100.4%show that this CL method has good practicability for detection of TBHQ and HQ.