Several Methods For Determination Of Natural Active Materials And Their Applied Research

Chemiluminescence analysis, based on the light emission produced in certain chemicalreactions （chemical luminescence）, is a technique of the determination of trace amountspecies, There are many merits on CL, combined with flow injection analysis, such as simpleand cheap optical system, requiring no light source which avoids the effects of stray light andthe instability of light source, and thus expanding the quantitative analysis of application. Thispaper reviewed in system development of chemiluminescence analysis, the basic principle,the main reaction system and the principle of flow injection technology. Then we introducesome research work which is flow-injection chemiluminescence detection of natural products,and the possible reaction mechanism of chemiluminescence is also discussed simply. Thismainly research content of the thesis is as follows:1. A novel method for determination of andrographolide using flow-injectionchemiluminescence analysis was described in this paper. The chemiluminescence intensity ofthe solution was enhanced proportionally while the concentration of andrographolideincreased. Under the selected experimental conditions, the calibration curve ofandrographolide was linear within the range from0.2to35.0μg/mL with a linear equation.The detection limit （3σ） was7.42×10²μg/mL. The method has been successfully applied tothe determination of andrographis tablets with satisfactory results.2. Based on the phenomenon of inhibiting the shine, while chlorogenic acid inject intochemiluminescence system of Fe²⁺-H₂O₂-methylene blue, and combined with flow injectiontechnology, a new method of chemiluminescence determination of chlorogenic acid describedin this paper. Under the selected experimental conditions, the calibration curve of gibberellinsis linear within the range from1.0to5.0×10²μg/mL with a linear equation. At the case ofcontinuous determination of50μg/mL chlorogenic acid, the relative standard deviation （RSD,n=11） was less than3.62%. The method has been successfully applied to the determinationof industrial production with satisfactory results.3. A novel method for determination of gibberellins using flow-injectionchemiluminescence analysis is described in this paper. The chemiluminescence intensity ofthe solution was enhanced proportionally while the concentration of gibberellins increased.Under the selected experimental conditions, the calibration curve of gibberellins is linearwithin the range from0.005to0.1mg/mL. The detection limit （3σ） was4.23×10^-4mg/mL. Atthe case of continuous determination of gibberellins, the relative standard deviation （RSD, n=11） was less than2.31%. The method has been successfully applied to the determination of industrial production with satisfactory results.4. A novel method for determination of stevioside and rebaudioside-A usingflow-injection chemiluminescence analysis is described in this paper. The chemiluminescenceintensity of the solution was enhanced proportionally while the concentration of steviosideand rebaudioside-A increased. Under the selected experimental conditions, the calibrationcurve of stevioside is linear within the range from0.001to0.5mg/mL with a linear equation.The detection limit （3σ） was7.6×10⁴mg/mL. The calibration curve of rebaudioside-A islinear within the range from0.001to0.5mg/mL with a linear equation. The detection limit（3σ） was8.7×10⁴mg/mL. At the case of continuous determination of the mixture （steviosideand rebaudioside-A）, the relative standard deviation （RSD, n=11） was less than2.62%. Themethod was applied to the determination of industrial production.5. In a sulphuric acid medium, the fluorescence intensity of was improved largely, whilestevioside was injected into the system of sodium sulfite and cerium sulfate ammonium. Theexcitation wavelength was254nm; the emission wavelength was357nm. The calibrationcurve of stevioside was linear within the range from0.001to0.15mg/mL with a linearequation, the detection limit was7.2x×10^-4mg/mL, and thus a new fluorescence method fordetermination of stevioside was established. This method was easy to operate, high sensitivity,stability, and could be used for determination of stevioside in crude stevia rebaudiana.