Study On Adsorption And Detection Of Perfluorinated Compounds By Magnetic Pillar[5]Arene Porous Polymer

Perfluorinated compounds（PFCs）are a class of synthetic organic chemicals that have high surface activity,high heat resistance and high chemical stability and are widely used in a variety of commercial and manufacturing materials.PFCs are prevalent in the environment and can be accumulated and amplified in organisms through the food chain.Due to their long half-life,they are difficult to be metabolized and eliminated in the body,so the detection and removal of PFCs have attracted global attention.At present,the two most common PFCs compounds,perfluorooctanoic acid（PFOA）and perfluorooctane sulfonic acid（PFOS）,have been reported in relevant literature.They not only interfere with the organism’s reproductive system and immune system,but also have high persistence,biocumulative toxicity and long-distance migration to the ecological environment.However,PFCs in environmental media are generally at trace levels,and there are complex matrix effects and interference substances,making it difficult to detect directly.Therefore,for the quantitative analysis of PFCs,it is urgent to develop a new material with high enrichment efficiency,and establish a method with high sensitivity,strong selectivity and high accuracy.In this paper,a novel magnetic cationic water-soluble pillar[5]arene porous polymer（CWPA5@MNPs）was synthesized and used as a solid phase extraction adsorbent for PFCs enrichment.Combined with high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）,A new method for the quantitative analysis of cationic pillar[5]arene by solid phase extraction（SPE）coupled with high performance liquid chromatography-tandem mass spectrometry（CWPA5@MNPs-HPLC-MS/MS）was developed and applied to the detection and analysis of PFCs in actual water samples.The specific research contents are as follows:1)In this study,cationic water-soluble pillar[5]arene（CWPA5）was synthesized according to literature.Then,the magnetic cationic water-soluble pillar[5]arene porous polymer（CWPA5@MNPs）was prepared by solvothermal method using CWPA5 and Fe Cl₃·6H₂O as raw materials.The structure and morphology of CWPA5 and CWPA5@MNPs materials before and after modification were characterized by fourier transform infrared spectrometer（FT-IR）,nuclear magnetic resonance spectrometer（NMR）,X-ray diffraction（XRD）,thermogravimetric analyzer（TGA）,water contact angle analysis（CA）,vibrating sample magnetometer（VSM）,and transmission electron microscopy（TEM）.The results show that Fe Cl₃·6H₂O is reduced to magnetic Fe₃O₄ nanoparticles and covered by CWPA5rings.2)HPLC-MS/MS quantitative analysis was used to explore the adsorption effect of CWPA5@MNPs adsorbent on 13 perfluorinated compounds in water,namely,perfluorinated carboxylic acid of C₄-C₁₄,perfluorobutanesulfonic acid（PFBS）and PFOS.Finally,it was determined that CWPA5@MNPs had certain adsorption effect on perfluorinated carboxylic acid compounds of PFOS and C₉-C₁₄,and these 7 PFCs were selected as the target analytes for subsequent experiments.After optimization,the optimal adsorption conditions were obtained as follows:the mass of the adsorbent was 12 mg,the analytical solvent was HPLC grade methanol,the analytical volume was 9 m L,and the adsorption time was 12 min.The adsorption process and mechanism of CWPA5@MNPs for PFOS were investigated.The results showed that the adsorption process of PFOS on CWPA5@MNPs was a single layer adsorption and the maximum adsorption capacity was 18.52 mg/g.The adsorption process followed the pseudo-second-order reaction kinetics model,which indicated that CWPA5@MNPs had a fast adsorption kinetics for PFOS and could rapidly adsorb PFOS in a short time.3)Using CWPA5@MNPs magnetic solid phase extraction（MSPE）combined with high performance liquid chromatography-tandem mass spectrometry,CWPA5@MNPs MSPE-HPLC-MS/MS method was established.It only took 10 min to complete the analysis of 7 PFCs,with linear range of 0.03-100.00 ng/m L,LOD range of 0.008-0.070 ng/m L and LOQ range of 0.030-0.200 ng/m L.The intra-day and intra-day precision of the seven PFCs showed that the intra-day RSD range was 3.6-6.4%,intra-day RSD range was 1.3-7.0%,and recoveries were 86.1-107.5%,indicating that the method established in this study had high sensitivity,good precision and good stability.The method was applied to the analysis of water samples in the Nanhu river,and the recoveries were 81.4-107.2%with RSD values ranging from 1.0-8.1%.These results indicate that CWPA5@MNPs,as a magnetic solid-phase extraction adsorbent,can effectively enrich trace perfluorinated compounds PFOS and C₉-C₁₄in environmental water,which confirms the feasibility of the method established in this paper and can be used for the detection of PFCs in environmental water samples.This study provides a new material and analytical method for the adsorption,removal and detection of PFCs pollutants in the environment.