The Preparation Of Porous Material And Its Application In The Determination Of Pollutant Residues In Environment And Food Samples

Due to the low concentration of analytes in real samples and the complexity of matrix,sample preparations are often necessary for the separation and concentration of analytes before the final instrumental detection.During the past decades,the solid phase extraction?SPE?and magnetic solid phase extraction?MSPE?have been widely applied in sample preparation due to their advantages of high enrichment factor,ease of use and less consumption of organic solvents.As is known to all,the adsorbent plays a key role in the process of extraction for obtaining a high concentration factor and good extraction efficiency.Therefore,the development of new adsorbent that owns high adsorption capacity,good selectivity and stability is still a hot issue in the research field of solid phase extraction and magnetic solid phase extraction.According to the literature research and in the foundation of referring to existing adsorption materials,two kinds of porous organic polymer materials and nano-porous carbon materials were successfully synthesized and used as SPE and MSPE adsorbents in this work.Combining with high performance liquid chromatography?HPLC?and mass spectrum?MS?,the established methods were used for the determination of some pollutants in water and food samples.The main aspects which the dissertation concerned is as followed:1.The porous material polytriphenylamine?PTPA?was synthesized by using triphenylamine as monomer and dimethoxymethane as cross-linker.According to the characterization analysis by N2 adsorption-desorption isotherm,Fourier infrared spectrometer,X-ray diffraction measurement and scanning electron microscope,the PTPA material had a relatively high specific surface area which was 780 m² g^-1 and a spherical-shape morphology.For the assessment of the adsorption capacity of PTPA,it was used as SPE adsorbent for the extraction of chlorophenols in tomato and bottle juice samples coupling with HPLC-MS determination.The elements that influence the extraction efficiency were also optimized.Under the optimal conditions,the method recoveries for the four chlorophenols were in the range from 92.5%to 103.3%.For tomato sample,the enrichment factor was in the range from 110 to 150 and the limits of detection?S/N=3?for the four chlorophenols was in the range of 0.03⁰.1 ng g^-1.For bottle juice sample,the enrichment factor was in the range from 127 to 163 and the limits of detection?S/N=3?was in the range of 0.05⁰.3 ng mL^-1.The linearity response for the analytes existed in the range of 0.3⁴0.0 ng g^-1 for tomato sample and 1.0⁴0.0 ng mL^-1 for bottle juice sample.The correlation coefficients were all higher than 0.9813.2.The carbazole porous organic polymer material?Car-POP?was prepared by using carbazole as monomer and dimethoxymethane as cross-linker via a facile one-pot synthesis method.To evaluate its adsorption performance,the Car-POP was used as SPE adsorbent for the separation and enrichment four kinds of chlorophenols in honey and green tea samples prior to HPLC analysis.Under the optimal conditions,the method showed relatively high method recoveries range from 93.8%to 107.2%with the relative standard deviation?RSD?lower than 5.6%.And good linearity was obtained in the range of2.0⁴00.0 ng g^-1 for honey samples and 0.2⁴0.0 ng mL^-1 for green tea samples.The limits of detection for four kinds of chlorophenols was in the range from 0.2 to 0.5 ng g^-1 for honey samples and in the range from 0.03 to 0.3 ng mL^-11 for green tea samples.The analysis results indicate that the Car-POP can be a good candidate for the adsorbent of SPE.3.A phthalocyanines-containing polymer derived carbon?PCP-C?was successfully prepared by carbonization phthalocyanines-containing polymer which was prepared by solid synthesis method with several inorganic materials.According to the results of characterization,the PCP-C had a relatively high surface and large pore volume.It presented a morphology of graphitization stratified structure and can be a potential candidate used as SPE adsorbent.To explore the adsorption capacity of PCP-C,it was used as SPE adsorbent for the extraction of some phenylurea herbicides?PUHs?from water and vegetable samples coupling with HPLC detection.Under the optimal conditions,good linearity was obtained for the five PUHs in the range from 0.5 to 80.0 ng mL^-1 for water sample and from 0.2 to 80.0 ng g^-11 for vegetable samples.The limits of detection for the five analytes at the signal to noise ratio of 3 were 0.01⁰.02 ng mL^-1 for water sample,between 0.03 ng g^-1 and 0.10 ng g^-1 for vegetable samples.According to the results of standard addition measurement,the method recoveries for the five PUHs were higher than93.8%with the relative standard deviation?RSD?lower than 4.93%.The results of analysis indicate that the PCP-C is appropriate for the SPE adsorbent for the enrichment of pollutant.4.The biomass derived magnetic porous carbon?MPC?was synthesized by a facile,cheap and green route.In this work,the corn stalk was used as carbon source and was pyrolyzed together with KHCO₃ as the chemical activator and iron?III?salt as the magnetic reagent.According to the characterization results by scanning electron microscope,N₂ adsorption-desorption isotherm and magnetic measurement,the MPC had a structure of hierarchical pores with a high specific surface area.The magnetization curve of MPC showed that it was superpara-magnetic.To evaluate its adsorption performance,the MPC was used as MSPE adsorbent for the enrichment three kinds of carbamates pesticides prior to HPLC instrument analysis.From the results under the optimal conditions,the MPC showed great adsorption performance for the target analytes.For real samples,good linearity was obtained for the targets in the range from 0.1 to 100.0 ng mL^-1for water sample and in the range from 0.5 to 100.0 ng g^-1 for zucchini sample.The correlation coefficient was higher than 0.9992.The limits of detection for three kinds of carbamates in water sample was 0.03 ng mL^-1 and in the range of 0.20⁰.50 ng g^-1 for zucchini sample.