| Polymer monolith microextraction(PMME)is a recently developed technique in sample preparation,with several characters including environment friendly,simplicity,easy automation and high efficiency.As the core of PMME,capillary polymer microextraction column not only has a unique structure of aperture,which can accelerate the mass transfer and improve the efficiency of extraction,but also has a big specific surface area,which is helpful to improve the extraction capacity.When combined with ionic liquids that have excellent physical and chemical properties,the selectivity of capillary polymer microextraction column will be further improved.The combination of PMME and capillary electrochromatography is adapted to the current trend of miniaturization and highly efficient in separation field,and provides an ideals analytical method for environmental monitoring and residual analysis in food.In this thesis,a new type of PMME-CEC-AD online hyphenated technique was developed,the extraction mode and mechanism was discussed and ionic liquids functionalized capillary polymer microextraction columns were prepared and applied in the online enrichment and analysis of phenolic environmental estrogens and glycopeptide antibiotics,respectively.The main contents are listed as following:1.The column materials,extraction modes and hyphenated instruments of PMME were mainly introduced.The principle of CEC and its related detection techniques,especially the amperometric detection were overviewed.The application progress of ionic liquids in the study of capillary monolithic column preparation was introduced.Furthermore,the research content and significance of this thesis were put forward.2.The online PMME-CEC/cLC-AD system was established,the operation process of the online analytical system and the feasibility in analysis were described in detail.3.Based on in situ polymerization,a long carbon chain imidazolium ionic liquids modified poly(IL-co-LMA-co-EDMA)microextraction column was prepared and applied for the online PMME-CEC-AD enrichment and analysis of three phenolic estrogens including bisphenol A,nonylphenol and octylphenol.Some extraction conditions were optimized.Under the optimal separation and extraction conditions,three kinds of phenolic estrogens were baseline separated,with a linear range of 10.0～20000.0 μg/L and good intra-day and inter-day precision(RSD<9.0%,n=5).The detection limits(S/N=3)were 5.0~10.0 μg/L,which were improved by 100 times when compared with the direct analysis by CEC-AD.The method was applied to the analysis of water sample.The results of the online detection showed no significant difference compared to standard method of HPLC-FLD,and the recoveries were satisfactory.This online analysis method showed good selectivity and little matrix interference,which provides a new way for high sensitive detection of phenolic environmental estrogens in environment and food samples.4.Based on in situ polymerization,a hydrophilic imidazolium ionic liquids modified poly(IL-co-HEMA-co-EDMA)microextraction column was firstly prepared and applied for the online PMME-cLC-AD enrichment and analysis of three glycopeptide antibiotics including vancomycin,norvancomycin and teicoplanin.Some extraction and separation conditions were optimized.Under the optimal analysis conditions,three kinds of glycopeptide antibiotics were baseline separated,with a linear range of 10.0～12000.0 μg/L and good intra-day and inter-day precision(RSD<10.0%,n=5).The detection limits(S/N=3)were 1.0～8.0 μg/L,which were improved by nearly 1000 times when compared with the direct analysis by cLC-AD.The method was applied to the analysis of pig feed sample with good recoveries.This online analysis method showed good selectivity and low matrix interference which provides effective enrichment and analysis tool for high sensitive residual detection of peptide antibiotics in animal-derived food samples. |
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