Study On Trace Arsenic Detection Technology Based On Gas Phase Chemiluminescence

The risk of arsenic exposure caused by arsenic pollution has become a worldwide environmental safety issue,affecting hundreds of millions of people around the world.Existing standard detection techniques such as mass spectrometry can accurately measure arsenic and the amount of sample loss is small,but using an expensive and bulky equipment,cannot meet the technical requirements of rapid field analysis.In view of the above situation,this paper developed a rapid detection system for trace arsenic based on the principle of ozone-induced chemiluminescence by using the combination of hydride generation and gas phase chemiluminescence analysis and using the characteristics of high chemiluminescence sensitivity,fast measurement speed and simple device.The detection system was successfully applied to the measurement of arsenic in environmental samples.This paper first introduces the research progress of on-site detection technology of inorganic arsenic,including colorimetric method,electrochemical method,X-ray induced fluorescence spectrum and biosensor.Then the basic principles,characteristics and applications of hydride generation and chemiluminescence analysis are systematically discussed,including the reaction mechanism of As H₃ and O₃ chemiluminescence detection,the theoretical basis for the analysis of the participating reactants and the mechanism of hydride generation and flow analysis using the chemiluminescence kinetic curve.Based on the theoretical analysis,a rapid detection system for trace arsenic in the environment was constructed.The system design includes hydride generation sampling system,online ozone generation system,chemiluminescence detection system and software program design.Compared with other conventional detectors,the system has the characteristics of simplicity,lowest cost,rapid analysis response and automatic control.It prospects to develop into a miniaturized and portable arsenic detector in the future.Finally,the system condition optimization experiments were carried out,including the gain voltage control of photomultiplier tube,the frequency and time of A/D sampling,the position of the gas pipeline,acid and acidity,the concentration of potassium borohydride,the flow rate of carrier gas,the interference and elimination of detection methods and other important influencing factors.On this basis,the standard curve of the work was determined.The standard substance experiment was carried out and the recovery range was between 90%and 120%.The experimental results show that the system has high accuracy,precision and low detection limit.In order to further prove the reliability of the method,the real environment sample analysis experiment was carried out and compared with the standard method such as HG-AFS and ICP-MS..The results show that it has a good correlation.In summary,this paper developed a rapid detection technique for trace arsenic by studying the highly sensitive mechanism of inorganic arsenic chemiluminescence.The time sample detection is less than 2 minutes,and it has sufficient accuracy and sensitivity,which provides a good application prospect for rapid arsenic detection in the field.