Preparation Of Organic-inorganic Hybrid Monolith Based On POSS And Application In On-line In-tube Solid Phase Microextraction

Sample pretreatment is an important step in the whole analysis process to obtain accurate quantitative results.Miniaturization and automation of equipment are the trend of sample pretreatment.In-tube SPME is a pretreatment technique with low solvent consumption,simple operation and low cost.In-tube SPME can be easily coupled to HPLC using an on-line valve-switching technology,which realized the automation of extraction and analysis.And the on-line in-tube SPME-HPLC has become a sustainable and environmentally friendly green analysis technology.POSS-based hybrid monolith has potential application value in on-line in-tube SPME because of their high specific surface area,good mechanical stability and excellent swelling resistance.Three kinds of POSS-based hybrid monolith were synthesized as in-tube SPME adsorbents,which were coupled with HPLC to on-line analyze and detect organic pollutants in different foods.Details were as follows:(1)Poly(BMA-co-POSS)hybrid monolith was synthesized using POSS-MA as crosslinking agent and BMA as monomer.The poly(BMA-co-POSS)monolith was combined with HPLC to establish an on-line in-tube SPME-HPLC method to detect the PAEs of drinking water.After the optimization of the important factors(sampling volume,sampling flow rate,sample p H and desorption time),the linear range of five PAEs were0.1-60.0 ng m L^-1 and the LODs were 0.052-0.10 ng m L^-1.The spiked recoveries at three different concentrations(2.0,20.0 and 40.0 ng m L^-1)were between 76.5%and 113.4%.(2)The poly(?-CD-co-EDMA-co-POSS)monolith was synthesized using A-?-CD as monomer,POSS-MA and EDMA as crosslinking agent.The monolith has large specific surface area(286.98 m² g^-1),good swelling resistance,high permeability,good swelling resistance and excellent mechanical stability,which was applied to the on-line in-tube SPME-HPLC system to detect OPPs in honey.The LODs and LOQs of the method were0.015-0.025 ng m L^-1 and 0.050-0.083 ng m L^-1,respectively.The intra-day RSDs were between 0.8 and 1.4%,and the inter-day RSDs were less than 2.8%.In addition,the enrichment factors and extraction recoveries of the five OPPs were 1817-1899 and88.7-92.9%,respectively.The on-line in-tube SPME-HPLC method is befitting for the analysis and detection of five OPPs in honey.(3)A poly(POSS-co-AM-co-EDMA)monolith for extraction of BPs was synthesized using AM and POSS-monomethacryl substituted(mono-MA-POSS)as monomers and EDMA as crosslinker.The monolith was characterized by FT-IR?SEM?TG and XPS.The concentrations of BPs in milk were detected by on-line in-tube SPME-HPLC-UV mothod.The proposed method showed high extraction efficiency(EF>1028),good linearity(R²>0.9985)and good reproducibility(RSDs<2.7%).The LODs were found to be in a range of 0.030-0.055 ng m L^-1 and the spiked recoveries were between 85.4%and 111.8%.