Preparation And Characterization Of Imidazolyl Ionic Liquid-based Monolithic Column For On-line SPE

Biological samples are complex sample matrix, containing lots of proteins and fat matter, which would interference the analysis. In addition, the test component content in biological samples is generally low, and even to the trace level, therefore, the test component content needs enrichment before analysis. Solid phase extraction(SPE) is one of the most practical technology for sample preparation for its simple preparation, high throughput analysis, and good reproducibility. Aiming at the pretreatment materials in the pretreatment technology, this work prepared two kinds of SPE columns and successfully used in the biological samples for extraction, separation and quantitative analysis.Firstly, a monolithic column was prepared via in situ free-radical polymerization, of which, ionic liquid(IL) and glycidylmethacrylate as the co-monomers, ethylene dimethacrylate(EDMA) as the cross-linker, 1-dodecanol and cyclohexanol as porogens, 2, 2'-azobisisobutyronitrile(AIBN) as the initiator. The prepared monolith was successfully used as the sorbent of SPE coupled to high performance liquid chromatography(HPLC) for the simultaneous enrichment and quantitative determine of macrolide antibiotics in milk. The obtained monolithic column was characterized by infrared spectrometry, scanning electron microscopy, nitrogen adsorption-desorption measurement and mercury intrusion porosimetry, respectively. The method was validated by linearity, selectively, precisions, accuracies and recoveries, respectively. As a result, the polymeric material exhibited high selectivity. The method had good repeatability and low limit of detection,which was poper for on-line SPE and analysis hence antibiotics in milk.Secondly, in order to optimize the pore structure and permeability of the monolith, polyethylene glycol 200 and 1.2-propanediol were used as porogens. Then simultaneous enrichment and quantitative determination of dihydropyridine drugs in human plasma by on-line SPE in 30 min. The monolithic column had continious macropore structure and good permeability. Furthermore, the polymeric material was feasible to be used in the online SPE-quantitative analysis for hence antihypertensive in human plasma.