Determination Technology Of Trace Plant Hormones And Carcinoid Markers Based On Functional Hydrophilic Resin

In recent years,environmental pollution and food safety have occurred frequently,which endangered human health seriously.Under the background of Healthy China Strategy,the rapid sensitive methods are desired for the determination of harmful substances in complex samples such as environmental,food,and biological samples,which are of great significance to protect people's health.The trace levels of the analytes in complex samples should be separated,purified,and enriched with proper pretreatment before determination because the sample matrices such as environmental,food,and biological samples are complex and the concentration of the targets is low.Solid phase extraction(SPE)is widely applied for the extraction and purification of trace analytes in complex samples due to the advantages such as good purification efficiency,low solvent consumption,and simple operation procedure.The key parameter to SPE is the development of adsorbent.Therefore,a series of new functional hydrophilic resin,hydrophilic imprinted resin,and hydrophilic imprinted resin composite have been prepared in this study by using plant hormones(environment,food,and Chinese herbal medicine)and carcinoid tumors biomarkers(biological samples)as research objects.The synthesized adsorbents have been successfully used as SPE and miniaturized SPE adsorbents,solving the problem of matrix interference in complex sample anaysis.And then coupled with high performance liquid chromatography(HPLC),the efficient,accurate,and rapid analytical methods were established and realizing the accurate and rapid determination of trace analytes in complex samples.The established methods provided new ideas for the separation and determination of trace targets in environmental,food,Chinese herbal medicine,and biological samples.The main research contents of this paper are as follows:At present,hydrophilic phenolic resin materials have single surface functional group,less adsorption interaction with the analytes and harm to human health(formaldehyde is used as a crosslinking agent during the preparation of phenolic resin).In this study,a new functional hydrophilic phenolic resin was prepared using glyoxylic acid as the crosslinking agent and the carboxyl functional groups were introduced on the surface of hydrophilic resin meanwhile,which enriched adsorption mechanism of hydrophilic resin,improved the adsorption efficiency,and avoided the use of carcinogen formaldehyde.The synthesized functional hydrophilic phenolic resin was applied as the SPE adsorbent,the extraction parameters were optimized and extraction mechanism was investigated.Combined with HPLC,a sensitive anaysis method for trace indole plant hormones in cherry tomatoes was established and the limits of detection was0.005–0.006 ng/g.And finally,the sensitive and accurate determination of trace levels of plant hormones in cherry tomatoes was achieved successfully.Most molecular imprinted polymers(MIPs)have the problem of poor recognition ability in water or polar solvents.A new deep eutectic solvents-based hydrophilic molecularly imprinted resin(DES-HMIR)was prepared using hydrophilic resin preparation technology and molecular imprinting technique in this study.The DES-HMIR was obtained using water as the solvent,hexamethylenetetramine as the crosslinking agent instead of formaldehyde,and DES as the porogen,which solved the problem of poor recognition ability of MIPs in water.The static and competitive adsorption experiment results showed that the DES-HMIR exhibited good specific selectivity to expanding agent plant hormone,and the adsorption process for the analytes is chemical adsorption.The synthesized DES-HMIR was applied as the adsorbent of pipette tip solid-phase extraction(PT-SPE)for the determination of plant hormones in fruit and vegetable samples,and the proposed preparation process required only 5 mg of DES-HMIR.Moreover,the accurate determination of swelling agent plant hormones in fruit and vegetable samples was realized.In view of the MIPs can only recognize target,a new dual-template hydrophilic molecularly imprinted resin(DHMIR)was synthesized using multi-template technique and hydrophilic resin preparation method in this study.The DHMIR was prepared using two dummy templates with different molecular structures,which could realize the specific recognition of multiple plant hormones with different structures.The adsorption and molecular recognition mechanism of DHMIR was clarified using adsorption experiments.The synthesized DHMIR was applied as the adsorbent and the extraction procedure were optimized.Furthermore,a new analytical method for the determination of different kinds of plant hormones in red wine was established,and the accurate and rapid determination of different kinds of plant hormones in red wine was realized.In view of the imprinted sites are easy embedded and the slow mass transfer rate of MIPs,a new hydrophilic molecularly imprinted resin-graphene oxide composite(HMIR-GO)was prepared by growing the HMIR layer on GO in this study.The obtained HMIR-GO realized the rapid adsorption and extraction of gibberellin(the HMIR-GO reached more than 85% of its maximum adsorption capacity after 5 min of adsorption and reached adsorption equilibrium at approximately 30 min),improving the mass transfer rate of HMIR and solving the problems of the embedded imprinted sites of MIPs.The adsorption capacity of HMIR-GO was evaluated using the adsorption experiments and the the adsorption process for the gibberellin is chemical adsorption.The synthesized HMIR-GO was applied as PT-SPE adsorbent for the extraction of gibberellin in traditional Chinese herbal medicine samples.Finally,the rapid extraction and determination of gibberellin in Licorice samples was realized successfully.In the process of solving the problem of slow mass transfer rate of MIPs,the HMIR was also combined with hexagonal boron nitride(h-BN),and the HMIR layer was grown on the surface of h-BN in this study.The obtained hydrophilic molecularly imprinted resin-hexagonal boron nitride(HMIR-h-BN)can recognize the carcinoid tumors biomarker 5-hydroxyindoleacetic acid specifically,which also improved the mass transfer rate of HMIR and solved the problems of the embedded imprinted sites.The synthesized HMIR-h-BN was used as the SPE adsorbent and the extraction parameters were optimized.An accurate method for the determination of carcinoid tumors biomarker(5-hydroxyindoleacetic acid)in biological samples was established combined with HPLC,which had a significant purification effect.The developed method was applied to determine 5-hydroxyindoleacetic acid in urine samples.In view of the low specific surface area of MIPs,the HMIR microspheres were grown on the surface of mesoporous silica(SBA-15)to synthesize a new hydrophilic molecularly imprinted resin-SBA-15 composite(HMIR-SBA-15),which increasing the specific surface area of HMIR.The characterization results show that the mesoporous structure of SBA-15 was preserved well.The static and competitive adsorption experiment illustrated that the HMIR-SBA-15 showed good specific recognition to the gibberellin,and the adsorption process is chemisorption.The synthesized HMIR-SBA-15 was used as the adsorbent for the extraction and determination of gibberellin in paddy field water.The established method exhibited lower limit of detection(0.13 ng/m L),higher recoveries(85.0-101.9%),and better precision(RSD ? 3.6%).Finally,the developed method was applied to determine the gibberellin in paddy field water.