Synthesis Of Metal-organic Framework And Its Application In Micro Extraction Of Foodstuff

Metal organic frameworks(MOFs)have super high porosity and large surface area.MOFs can be compatible and variability.After processing and modification,metal organic frameworks also have certain thermal stability and water stability,which have potential to become important materials in extraction and separation.In this paper,we have studied and established a new metal organic framework as a kind of adsorbent for extraction and separation,and applied to testing of trace substances in foodstuff,in order to improve the efficiency,sensitivity and selectivity of sample analysis.The main contents of the research were as follows:1.A new metal organic framework Zr-BTB was synthesized and characterized by XRD.A micro solid phase extraction method based on Zr-BTB metal organic framework as sorbent was developed for the extraction of phenylurea herbicides from corn and wheat,and its quantitative analysis was carried out by ultra performance liquid chromatography coupled with mass spectrometry.The linearity of the method is satisfactory(r~2>0.99),the detection limit is 0.05-0.36 ng/mL,and the recovery rate of the added standard is 97.55-99.85%.Compared with other methods,the method has the advantages of less reagent consumption and shorter extraction time.2.A new type of metal organic framework DUT-67 was synthesized and characterized by XRD.Based the metal organic framework DUT-67 as sorbent on micro solid phase extraction method for the extraction organic mercury in fish samples,and were analyzed by capillary electrophoresis with DAD detector.Under the optimum conditions,the extraction and separation of three kinds of organic mercury,the detection limit was 17.06-39.6 ng/mL,standard addition recovery of83.2-92.4%.3.A new type of metal organic frameworks MOF-808 was synthesized by the laboratory,and use to extract the ginsenosides in the leaves of ginseng by the matrix solid phase dispersion.Five kinds of saponins(ginsenoside Rg1,Re,Rg2,Rb1,Rd)were determined by super high performance liquid chromatography with quadrupole time of flight mass spectrometry.When the negative ion mode was used,the target4.analyte is ionized to[m-H]~-and[m+COOH]~-adducts ions.And a response surface model is established to verify the optimal scheme.The linearity of the method is good(r~2>0.99),the detection limit is 0.087-0.114?g/mL,and the recovery rate was 87.04-103.78%.Compared other methods,this method has the advantages of organic reagent using less,shorter extraction time and simple operation.