Development Of Mass Spectrometry Analytical Method For Metal Organic Frameworks And Its Exposure Studies In The Plant

In recent years,metal organic frameworks(MOFs)have been widely used in catalysis,separation,adsorption,sensor and drug delivery due to their large specific surface area,adjustable pore size and easy surface functionalization.With the gradual research and commercialization of MOFs,the massive use of MOFs may enter into the environment and affect the environment.At present,the research on MOFs is mainly in the synthesis,application and characterization.However,there are a few studies on the impact of MOFs on the environment.Therefore,this thesis mainly discussed the stability of MOFs in the environment,their distribution in plants and their impact on plant growth.This thesis is mainly composed of the following four chapters.The first chapter,we reviewed the development,synthesis methods,characterization and application of MOFs in recent years,summarizes the development of LA-ICPMS-based analytical methods in recent years and their applications in environmental research,and puts forward the research purpose and significance of this article.The second chapter proposes a Cr-based metal fingerprint label-free method for detection of MIL-101(Cr).Firstly,we explored stability of MOFs in the environment,and three release rate of metal ions was used the stability index of MOFs.The stability of the powdered and suspension in the water phase under oxygen,air,and nitrogen conditions were tested respectively.Combined with SEM,the results indicated that the morphology of MIL-101(Cr)was no change when placed under different conditions for6 h,and its metal ions release rate does not exceed 1%.Finally,the MIL-101(Cr)was placed in the DOM,and the xenon lamp was used to simulate natural light.The release rate of metal ions in 168 h was tested.It was found that the maximum release rate of metal ions in the DOM environment was 0.26%.The maximum release rate of metal ions in water is 0.34%.Therefore,MIL-101(Cr)can exist stably in the environment.The third chapter that the content of MIL-101(Cr)in different parts of soybeans when exposed to different concentrations and times were discussed.In different time,the soybean was exposed 100mg/L MIL-101(Cr)suspension,the result indicated the length of soybean increase with time increasing,when added Silwet L-77,although the length of soybean gradually increase with time increase,in compare to no Silwet L-77,the length of soybean was low.The soybean was exposed in different concentrations after 7 days,the results indicated that the MIL-101(Cr)could promote growth.When added 0.05%Silwet L-77,the results indicated that the MIL-101(Cr)could promoted grown in low concentration and inhabited grown in high concentration,when the concentration up to200 mg/L.the leaf of soybean was yellow.The fourth chapter Laser ablation coupled inductivity coupled plasma mass spectrometry(LA-ICP-MS)is a powerful imaging analysis tool.It ablates solid samples,carries them into the ICP-MS by carrier gas,and finally passes Mass spectrometry screening and quantification.This method has low detection,high spatial resolution,and can directly analyze solid samples.This chapter mainly used Cr as the indicator metal of MIL-101(Cr),and uses LA-ICP-MS to image the longitudinal and cross-sections of soybean roots when exposed to 100 mg/L MIL-101(Cr)suspension after 7 days.The results show that the MIL-101(Cr)can enter the surface of soybean roots.