| This thesis includes two parts. In part one, the recent development of the analytical methods of chemical oxygen demand is reviewed. The review involves the development of the spectrometry, the electrochemistry, the flame atomic absorption spectrometry and other analysis means. The research reports are focused on: (1)Chemiluminescence rapid determination of aquatic COD with flow injection analysis (the K2Cr2O7 method); (2) Chemiluminescence system for automatic determination of chemical oxygen demand using flow injection analysis (the KMnO4 method); (3) Chemiluminescence rapid determination of Organophosphorous pesticides with flow injection analysis.Part One Summary The development of the analysis of chemical oxygen demandIn all kinds of contaminates, the organic contaminate is the fastest increasing and most serious one, Chemical Oxygen Demand (COD) is just the comprehensive index to valuate the degree of organic pollution. It's also the important parameter in supervising the water quality. COD is defined as the amount of oxygen equivalents consumed in the oxidation of organic compounds by strong oxidants (such as dichromate, permanganate), represents the total pollutants load of most wastewater discharges (it should be converted into oxygen's mass concentration (mg/L)). And it will be rather meaningful for water pollution preventing and supervising to grasping and controlling the amount of COD of water in time. This review introduces different methods of the determination of COD value, especially by spectrometry, electrochemistry, flame atomic absorption spectrometry and other analysis means. The procedures of the evaluation COD methods are complicated, and not suitable for analyzing the batch samples and monitoring on line.Flow-injection Chemiluminescence (CL) is known to be a powerful analytical technique that promises high sensitivity, wide linear range, simple instrumentation, and rapid, reproducible means of detection, and has been applied successfully to the determination of many environmental pollutants. In this paper, tow simple CL systemfor on-line determination of COD using flow injection analysis is proposed.Part Two Research Reports 1% Chemiluminescence Rapid Determination of Aquatic COD With Flow InjectionAnalysisA novel chemiluminescence (CL) combined with flow injection system for rapid determination of chemical oxygen demand (COD) of aquatic system is described in this paper. It is based on that the acidic K2Cr2O7 can be reduced into Cr(III)by reducible matter in the water, and the generated Cr(III)can catalyze the luminol- H2O2 system to produce the strong CL emission. In this method, the reduction reaction does not need other catalyzer and analysis can be completed on-line. The linear range is 20-10000 mg/L with the detection limit of 10mg/L. The system has been applied to determine the COD of the water sample with satisfactory results.2 , Chemiluminescence System for Automatic Determination of Chemical Oxygen Demand Using Flow Injection AnalysisA novel chemiluminescence (CL) system for automatic determination of chemical oxygen demand (COD) combined with flow injection analysis is proposed in this paper. In this system, potassium permanganate is reduced to Mn2+ which is first adsorbed on a strongly acid cation-exchange resin mini-column to be concentrated during chemical oxidation of the organic compounds at room temperature, while the excessive MnO4- passes through the mini-column to be waste, then the concentrated Mn2+ is eluted reversely and measured by the luminol-H2O2 CL system. The calibration graph is linear in the range of 4-4000 mg /Land the detection limit is 2 mg/L. A complete analysis could be performed in 1.5 min including washing and sampling, giving a throughout of about 40/h. The relative standard deviation was 4A% for 10 mg/L COD (n=11), This CL flow system for determination of COD is very simple, rapid and suitable for automatic and continuous analysis. The presented system has been applied successfully to the determination of COD of water samples.
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