Study On On-line Detector For Mercury Concentration In Flue Gas Based On Cold Atomic Fluorescence Spectrometry

Cold atomic Fluorescence Spectrometry is a trace element analysis method based on the measurement of the relationship between the intensity of mercury and the concentration of mercury based on the fluorescence intensity of mercury vapor excited by ultraviolet light at a wavelength of 253.56 nm emitted by a mercury lamp,which is between atomic absorption spectroscopy and atomic emission spectroscopy.This method absorbs the advantages of both and avoids the shortcomings of both.At present,atomic fluorescence spectrometry has been applied in many fields,such as hospital diagnosis,environmental pollutant monitoring,underground inspection,biology,food safety and so on.In this paper,the current research status of atomic fluorescence spectrometry and atomic fluorescence spectrometry at home and abroad is investigated firstly,and the theoretical research of atomic fluorescence spectrometry technology is carried out,which lays a foundation for data processing of experimental results.After a comprehensive understanding of the atomic fluorescence spectrometry technology,the mercury concentration detector is designed.The design principle of the mercury concentration detector and the mechanical design principle of each component are introduced.At the same time,the design structure of each component is demonstrated.In order to verify the feasibility of the mercury concentration detector designed in this project,a verification experiment is designed.The verification experiment proves that the instrument has good linear correlation,stability,high measurement accuracy and high repeatability.Then,the optimal operating parameters of the instrument are determined by using the instrument to detect mercury in water.The effects of different acidity?HCl?of the carrier on the determination of mercury are investigated and two different kinds of reducing agents?SnCl₂ and KBH₄?are used in the experiment.Through processing the experimental data,SnCl₂ is found to be more helpful to improve the accuracy of the experiment.Meanwhile,the influence of the concentration of reducing agent on the determination results is further studied.Experiments show that under the optimal conditions,the linear correlation coefficient of the standard curve is 0.99986,the detection limit of the instrument is 0.001?g/L,and the lower limit of determination is 0.004?g/L.The mercury concentration detector designed in this paper has low detection limit,high precision,fast response,simple mechanical structure,simple operation and easy to carry.