| Arsenic and antimony are non essential elements for human body and harmful to human health at very low content.In order to realize the effective monitoring and treatment of arsenic and antimony pollution,it is necessary to expand new principles and technologies to realize the on-site,sensitive,accurate and rapid determination of trace arsenic and antimony.At present,the sensitivity of microplasma source optical emission spectrometry for the determination of trace arsenic and antimony still needs to be improved and extremely dependent on hydride generation（HG）.In this thesis,a variety of new microplasma excitation sources-optical emission spectroscopy with hydrogen assisted have been developed to realize the sensitive detection of trace arsenic and antimony without hydride generation.In addition,a portable instrument has been developed and the preliminary used for the determination of trace arsenic and antimony in real samples.The main research contents are as follows:1.Based on atmospheric pressure glow discharge（APGD）microplasma excitation source,a method for the determination of trace antimony by atmospheric pressure glow discharge-optical emission spectroscopy（APGD-OES）was developed.APGD excitation source forms a homogeneous dispersion plasma in Ar-H2 mixed atmosphere,which can effectively reduce spectral interference and ensure the analyte is efficiently excited by the plasma.In addition,HG injection can reduce antimony in the solution to gaseous antimony hydride and sweep into the APGD for excitation.The sample introduction efficiency is high and the analytes are separated from the solution matrix,which makes HG-APGD-OES have the advantages of high sensitivity and strong anti-interference ability.The effects of KBH4 concentration,sample flow rate,argon flow rate and discharge current on the excitation performance were investigated.Under the optimum conditions,the detection limit of sb by HG-APGD-OES was 0.14μg L-1.The method has successfully detected standard simulated water samples,standard samples of stream sediments and actual water samples of Lengshuijiang,which lays a foundation for the development of portable instruments for the on-site,sensitive and accurate detection of trace antimony.2.A novel solution anode glow discharge（SAGD）microplasma excitation source was developed.And hydrogen assisted-solution anode glow discharge-optical emission spectroscopy（SAGD-OES）using direct solution injection was established for the sensitive detemination of trace arsenic and antimony without hydride generation.It was found that the vapor generation and excitation of arsenic and antimony occurred simultaneously in the SAGD,contributing to the significant improvement in the sensitivity of arsenic and antimony without additional vapor generation.The detection limits of arsenic and antimony are 1.4 and 0.85μg L-1,which was three orders of magnitude higher than the traditional microplasma-optical emission spectrometry with direct solution injection method and comparable to other reported microplasma-OES coupled with HG.It is further verified that hydrogen can greatly improve the vapor generation process of arsenic and antimony in SAGD-OES and the generated volatile species are molecular in nature.The interference of coexisting elements was studied.Arsenic and antimony reference materials and real water samples were detected.This method eliminates the complex hydride generation system and hazardous reagent,which has great potential to develop on-site,sensitive and green arsenic and antimony analysis technology and instruments.3.A new droplet anode discontinuous discharge（DADD）microplasma excitation source was developed to directly detect trace antimony in solution under hydrogen-assisted sensitization.Compared DADD-OES with SAGD-OES,the device structure is more simplified,and the power consumption of excitation source and sample consumption（10μL）are greatly reduced.The detection time is shorten（20 s）and in a very short time（<1 s）,the high-efficiency vapor generation and excitation of antimony are completed in DADD-OES.Theoretically,it is expected to achieve high-throughput detection（3000 per hour）.Under the optimal conditions,the detection limit of antimony is 7μg L-1（70 pg）.The effects of different discharge atmosphere,droplet volume,solvent electrons,discharge distance,p H value and discharge current on the analytical performance of DADD-OES in the detection of antimony were discussed.The anti-interference ability of coexisting metal elements was investigated and the real samples were tested.The development of portable instruments（battery powered）by this method can realize the long-term,rapid and sensitive analysis of field trace samples,and can meet the needs of on-site mass and high-throughput sample analysis.4.Based on atmospheric pressure glow discharge-optical emission spectrometry,a portable instrument prototype was developed for the detemination of trace arsenic and antimony.The research and development of portable APGD-OES prototype mainly includes the comprehensive development of software and hardware such as sample injection system,excitation detection system,circuit system and instrument software.An integrated detachable APGD excitation source is designed and the main body of the prototype is made of engineering plastics with light weight and corrosion resistance.The size of the portable instrument is 420 mm×280 mm×180 mm（length×width×height）with the total weight at 7.2 kg.Beside,the power consumption of APGD source and the prototype are about 10 and 45 W,respectively.The portable APGD-OES instrument was used to detect arsenic and antimony in various actual water samples and compared with the detection results of ICP-OES to verify the reliability of water sample detection.Further,the portable APGD-OES instrument was carried to several demonstration bases for field/on-site detection,and the arsenic content in soil was successfully detected and compared with the ICP-MS detection results to verify the reliability of on-site soil analysis. |
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