Supramolecularly Imprinted Sample Pretreatment Methods Based On β-Cyclodextrin With Unsaturated Double Bond And Its Applications

The molecular imprinting sample pretreatment technology has been rapidly developed in the past ten years.This is due to the high selectivity of the molecular imprinting technology itself,and it is very easy to combine with other sample pretreatment methods to derive a variety of molecular imprinted samples,such as magnetic microsphere microextraction,solid-phase extraction,stir bar adsorption extraction,solid-phase microextraction,and based on molecularly imprinted polymeric adsobents.Molecular imprinting sample pretreatment technology has been widely used in the analysis of trace analytes in environmental samples,biological samples,food samples,and other complex samples.Pharmaceutical and personal care products(PPCPs),are different kinds of novel contaminents,including personal care products,human and veterinary drugs,agricultural medicines,chemical additives and consumer products.PPCPs have strong persistence,biological toxicity and bioaccumulation,and it will be risky to human health and the environment.The determinaton of trace amounts of PPCPs and its removal in aquatic environment is currently a difficult problem to be solved effectively,and it has increasingly attracted widespread attention.In this paper,on the basis of homemade β-cyclodextrin(β-CD)functional monomer,supramolecular host-guest recognition technology,molecular imprinting technology,and micro-extraction technology are combined to prepare bifunctional monomer supramolecular imprinted stir bar adsorption extraction coating and supramolecular imprinted solid phase microextraction fiber coating.Furthermore,a fiber array extraction platform was constructed based on homemade supramolecularly imprinted polymeric solid-phase microextraction coatings,which was applied to the analysis of endocrine disruptors and parabens in actual polluted water.β-cyclodextrin functional monomers were used to prepare supramolecularly imprinted polymeric microextraction coatings.The development of a series of novel β-cyclodextrin functional monomers also solved the problem of limited functional monomers for molecularly imprinted polymers.There are four aspects to introduce the main research.(1)Mono-(6-O-p-toluenesulfonyl)-β-CD and mono-(6-ethylenediamine-6-deoxy)-β-CD were derived from β-CD.On this basis of these two compounds,six novel functional monomers were further synthesized.They were mono-(6-p-vinylbenzenesulfonyl-6-deoxy)-β-CD,mono-(6-ethylenediamine-(Nacryloyl)-6-deoxy)-β-CD,mono-(6-ethylenediamine-(N-methacryloyl)-6-deoxy)-β-CD,mono-(6-N-allylamino-6-deoxy)-β-CD,mono-(6-N-diallylamine-6-deoxy)-β-CD,and mono-(6-N-propargylamino-6-deoxy)-β-CD,respectively.All the obtained functional monomers were characterized by infrared spectroscopy(IR)firstly,then by nuclear magnetic resonance spectroscopy,including 1H NMR and 13 C NMR,and finally by mass spectrometry(MS).(2)A novel stir bar sorptive extraction coating of bifunctional monomer imprinted polymer was prepared.β-cyclodextrin derivatives and acrylamide were used as bifunctional monomers.Bisphenol A(BPA)was selected as the template molecule.Glass capillary were employed as the substrate and reaction vessel to prepare the coatings.And the coating length was 1.8 cm.The extraction capacity for the template molecule BPA of the bifunctional monomer supramolecular imprinted stir bar sorptive extraction coating was significantly higher than that of each single functional monomer MIP coating.The data indicated that the bifunctional monomers triggered supramolecular imprinted coating was conducive to improve the extraction capacity and analytical sensitivity.The dual-functional monomer supramolecular imprinted stir bar sorption extraction coating has good selectivity to six endocrine disruptors.The extraction performance was better than non-imprinted coating and two single-functional monomer imprinted coatings.The enrichment factors for six analytes of the supramolecular imprinted coating were 27-500 times to the enrichment factors of the commercial PA coating.(3)An analytical method using stir bar sorptive extraction prior to chromatography detection for the analysis of three endocrine disruptors in actual water samples was established.The linear range was 0.1-200 μg/L,and the detection limit is between 0.004-0.01 μg/L.Three target analytes were found in actual samples,and the concentration was between 0.14-30.90 μg/L.This method was further used in the spike recovery test of two actual water samples.The recovery of 92%–119% was obtained.Its relative standard deviation(RSD)was 1.6%–9.7%(n=3).(4)A novel supramolecularly imprinted coating for solid-phase microextraction fiber was proposed.The fiber array extraction device was constructed by the molecularly imprinted fiber coatings.The extraction method by supramolecular imprinted fiber array was established.It was applied to the analysis of paraben pollutants.The length of the molecularly imprinted fiber coating was 1.8 cm.The fiber array was composed by three fiber coatings.The structure of the molecularly imprinted fiber coating was also characterized.The extraction amounts of paraben compounds by the supramolecular imprinted fiber array were significantly higher than that by single molecularly imprinted fiber.The supramolecular imprinted fiber array had good selectivity for three paraben compounds.The supramolecular imprinted fiber array also had better extraction performance than that of the non-imprinted fiber arrays based on cyclodextrin functional monomer and common functional monomer imprinted fiber arrays.The extraction amounts of parabens based on supramolecular imprinted fiber array were 3777-6174 times to that of PA commercial coating array.The supramolecular imprinted fiber array could be used more than 50 times.(5)An analytical method using fiber array extraction prior to chromatography detection for the analysis of three parabens in actual water samples was established.The linear ranges were 0.01-200 μg/L and 0.05-200 μg/L for different analyts.The detection limit was between 0.003-0.02 μg/L.Two target analytes were found in the actual samples,and the concentration was between 0.06-0.11 μg/L.This method was further used in the spike recovery test of two actual water samples.The recovery was between 81.42%-117.36%,and the RSD was between 0.58%-8.17%(n=3).