Preparation Of Hollow Nanomaterials Derived From Metal Organic Framework And Research On Its Extraction Performance

Solid-phase microextraction(SPME)is a new sample pretreatment technology,which combines the purification,extraction,concentration and injection analysis steps of analytes.It has been widely used in environmental analysis,food analysis,drug analysis due to its excellent performance,such as simple operation,low consumption of organic solvents,and high sensitivity.And it is one of the most effective sample preparation methods.However,some commercial fibers fail to meet the needs of environmental analytical chemistry due to the shortcomings of limited types of coating materials,poor specificity,poor thermal stability,and easy breakage.Therefore,the development of new SPME coating materials is of great significance to achieve the enrichment and separation of analytes from complex environmental samples.This thesis mainly explores the extraction performance of polycyclic aromatic hydrocarbons(PAHs)in water environment by using two new types of SPME fibers which using hollow nanomaterials derived from metal organic frameworks as coating materials combined with high performance liquid chromatography.This paper was mainly composed of the following three chapters:1.ZIF-67 was transformed into hollow nanomaterial by etching technique using tannic acid and further coated it on the surface of stainless steel wire(SSW)through physical adhesion method,which was used as solid phase microextraction(SPME)fiber to capture fifteen PAHs rapidly.The orthogonal array design(OAD)was used to quickly find the optimum extraction conditions.Besides,the adsorption results showed that the extraction capacity of the fiber made from hollow nanomaterials was much higher than that made from the original ZIF-67 and commercial coatings.These results showed that?-?interaction,hydrophobic interaction and unique hollow structure enhanced adsorption performance effectively.2.The hollow multi-shell structure cobalt tetroxide/carbon(HoMS-Co₃O₄/C)nanocomposite was successfully prepared by the ligand conversion method followed by high-temperature carbonization based on ZIF-67.And a novel spiral solid phase microextraction(S-SPME)fiber was designed,which was coated with pre-prepared HoMS-Co₃O₄/C nanomaterial by using gluing method.Fifteen Polycyclic aromatic hydrocarbons(PAHs),four Brominated flame retardants(BFRs),and seven Endocrine chemicals(EDCs)were used to investigate the extraction performance of HoMS-Co₃O₄/C coated S-SPME fiber.The results showed that this kind of carbon-mixed composite material coated fiber exhibitted excellent enrichment ability and high selectivity for PAHs,it might since there were strong?-?stacking force,hydrophobic interaction between analytes and HoMS-Co₃O₄/C coating,also the HoMS coating and the spiral fiber could greatly increase the contact area between adsorbent and target compounds.Under the optimal conditions,the method processed good linearity,low detection limit,wide linear range and good reproducibility.