Applications Of Some Metal Organic Frameworks In Separation And Analysis

Metal organic frameworks(MOFs)are a kind of self-assemled coordination polymers with infinite structures which was constructed from clusters or chains of metal ions connected by organic linkers.MOFs have been widely applied in separation and analysis due to its unique properties.In order to expand the application of MOFs in separation and analysis,this dissertation focused on fabiracating MOFs and MOFs composites as SPME coatings,stationary phase and adsorbents.The paper includes the following seven parts.1.The characteristics and fabrication of MOFs were summarized.The applications of MOFs in sample pretreatment,chromatographic separation and dye removals were summarized in detail.Also,the significance and main contents of this dissertation were elaborated.2.A MIL-53(Fe)SPME coating fiber was prepared via immobilization with resin.An optimized method based on MIL-53(Fe)SPME coating coupled with GC-MS could efficiently extract and analysis polychorinated biphenyls.The method showed low limits of detection(0.45-0.75 ng/L)for PCBs,and RSD ranged from 2.3 to 8.2%.The recoveries of Xihe River water and fish feed ranged from 82.2 to 115.2%.3.A UiO-66 SPME coating biber was prepared via covalent bonding method and used for highly extract and analysis of PAHs.The limits of detection were between 0.28-0.60 ng/L.The RSD of intra-days and inter-days ranged from 1.5-8.9%.This method was used for determination of ten PAHs from Minjiang River water and soil with recoveries between 83.8%and 116.6%.4.MIL-53(Fe)applied as a novel stationary phase for reverse-phase high performance liquid chromatography(HPLC)separation of positional isomers was described for the first time.Under the optimized conditions,baseline separation of xylene,dichlorobenzene,chlorotoluene and nitroaniline isomers was achieved on the MIL-53(Fe)packed column within a short time.Effects of mobile phase and column temperature on HPLC separation were studied,and the retention mechanism on the MIL-53(Fe)were disccused in details.5.A silica-UiO-66 composite was fabricated by a simple hydrothermal method and then applied as liquid chromatographic stationary phase for fast and efficient separation.Under the optimized conditions,baseline separation of ethylbenzene(EB)and styrene was obtained with high resolution and short retention time.In addition,the silica-UiO-66 composite packed column also showed some advantages in separation of positional isomers,with which baseline separation of EB.and xylene,chlorotoluene and dichlorobenzene isomers was achieved.6.UiO-66 was used to fabricate uniform spherical core-shell silica@UiO-66 microspheres as a stationary phase via a facile method.The silica@UiO-66 microspheres packed column gave fast and efficient separation of xylene,dichlorobenzene and chlorotoluene isomers within 3 min with low back pressure and good chromatographic peak shape.Baseline separation of ethylbenzene(EB)and styrene was also achieved on the silica@UiO-66 microspheres packed column within 1.2 min.7.A novel magnetic Fe3O4@SiO2@UiO-66 core-shell microspheres were fabricated with a silica-coated magnetic core and UiO-66 shell via hydrothermal method.The obtained magnetic microspheres exhibited high magnetization,high surface area and good chemical stability.Fe3O4@SiO2@UiO-66 microspheres were applied to the adsorption of methyl orange(MO),and exhibited a relatively large adsorption capacity of 208.33 mg/g for MO at 30?.