Metal Organic Frameworks-based Magnetic Solid Phase Microextraction And Its Application

Specific detection of target analytes from complex samples is the basic requirement of modern drug analysis.Appropriate sample pretreatment methods can not only remove impurities but also selectively enrich target analytes from complex sample matrix,thus improving the accuracy and sensitivity of the entire analysis method.Magnetic solid phase microextraction(MSPE)combines magnetic materials and magnetic separation technology with extraction,which greatly simplifies the operation process,and shows good operability,large adsorption capacity as well as high extraction efficiency.Extraction sorbents is of great importance for MSPE,development of novel extraction sorbents is beneficial to improvement of the extraction selectivity and efficiency.In this work,we aimed to take metal organic frameworks(MOFs)as novel MSPE stationary phase extraction sorbents and explored their modification on magnetic nanoparticles as well as the extraction performance.After combining with high performance liquid chromatography(HPLC),the MOFs-modified magnetic nanoparticles were applied to high sensitivity drug analysis.The main contents include the following two parts:1.Novel metal-organic framework-1210(zirconium/cuprum)modified magnetic nanoparticles for magnetic solid phase microextraction of benzophenones(BPs)from soils: MOF-1210(Zr/Cu)is a porous heterometallic cluster-based MOF with high porosity,large specific surface area,excellent stability,and high adsorption capacity.It is a promising stationary phase extraction sorbent.MOF-1210(Zr/Cu)-MNPs were prepared by a solvothermal method.Based on the hydrogen bonding interaction,coordination interaction or hydrophobicity,π-π staking interaction,MOF-1210(Zr/Cu)-MNPs showed high extraction efficiency to BPs.The MOF-1210(Zr/Cu)-MNPs-based MSPE-HPLC method was developed and showed wide linear range(0.1-300.0 ng/m L),good linear correlation(R ≥ 0.9982)and high sensitivity with the limit of detections in the range of 0.01-0.02 ng/m L.This method was also successfully applied to the determination of three BPs in environmental samples,good recoveries obtained(87.6-113.8%)with excellent repeatability.2.Metal organic framework-801 based magnetic solid phase microextraction and its application in analysis of preterm labor treatment drugs: Indometacin,acemetacin and sulindac are commonly used in the treatment of preterm labor,accurate monitoring of their content is of great significance to protect newborns from severe irreversible harm.This work mainly focused on the study of the PEI-MNPs@MOF-801-based MSPE-HPLC method.Firstly,the polyethylenimine-modified magnetic nanoparticles(PEI-MNPs)were prepared by a one-step method,and the fumaric acid was immobilized by amidation reaction between PEI and fumaric acid.Then PEIMNPs@MOF-801 were prepared by in situ modification of MOF-801 onto PEI-MNPs with a solvothermal method.Fourier transform infrared spectroscopy,x-ray diffraction,x-ray photoelectron spectroscopy,and transmission electron microscopy characteration demonstrated the successful preparation of PEI-MNPs@MOF-801.The effects of preparation and extraction conditions on extraction efficiency were investigated.Under the optimal conditions,PEI-MNPs@MOF-801-based MSPE-HPLC showed high extraction efficiency on indomethacin,acemetacin,and sulindac with good repeatability.