| Separation and determination of trace substance in real sample is an important research area in ananytical chemistry. Due to complex matrix and low content percentage, effective pretreatment methods are employed prior to analysis in order to reduce interference and enhance sensitivity. Traditional pretreatment methods, such as solid-phase extraction(SPE), cloud point extraction(CPE), and iquid-liquid extraction(LLE) are time-consuming during the extraction process. Polymer monolith microextraction(PMME), which is based on solid-phase microextraction(SPME), has drawn much attention because of easy operation, fast analysis, high extraction efficiency, and low resources consumption.Polymer monolithic column has been recently developed as a new separation media, which is fabricated with unsaturated functional monomers and cross-linkers inside an activated capillary and anchored to the wall through chemical bonding by in situ polymerization. With the interesting properties of high mechanical strength, little consumption of solvent and sample, high porosity and surface area, low flow-resistance, and high binding capacity, monolithic materials have been more and more attractive and widely used in many fields. However, the development and application of monolithic column are limited with rich species, various properties, and complex matrix. Therefore, the modification and functionalization of polymer monolithic column was an irresistible trend in scientific research. The aim of the present study is to design and synthesize new functionalization monolithic column materials coupled with high-performance liquid chromatography(HPLC) for the determination of several compounds. The following four sections are included.1. The current study describes the enrichment ability of ZnO-modified methacrylic acid-co-ethylene dimethacrylate polymer monoliths as stationary phasesfor the simultaneous determination of fluoroquinolone antibiotics(FQs) combined with HPLC. The prepared monolith was characterized by scanning electron microscopy(SEM), Fourier-transform infrared spectra(FT-IR), and X-ray photoelectron spectroscopy(XPS), and thermogravimetric analysis(TGA). To obtain high extraction efficiency for FQs, conditions of PMME process, including eluent type, sample pH, sample volume, and eluent flow rate were investigated. Under the optimized conditions, the method was validated. Within the concentration range of0.05-5 μg mL-1, the square of correlation coefficient(R2) was found to be in the range of 0.9949–0.9982. LOD and LOQ were determined in the range of 0.007–0.034 and0.026–0.115 μg mL-1, respectively. The intraday and interday precisions of the target FQs were determined to be in the range of 3.8–8.0% and 4.7–9.8%, respectively.Furthermore, to investigate the reproducibility of monolith, the intrabatch and interbatch RSDs were also determined to be lower than 7.8 and 8.2%. Compared with the conventional methacrylic acid based monolith, the developed monolith exhibited a higher enrichment capacity because of the introduction of ZnO into the preparation process.2. PMME-HPLC method was developed for the determination of adenosine triphosphate(ATP), adenosine diphosphate(ADP), and adenosine monophosphate(AMP). The obtained poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith was characterized by SEM, FT-IR, and XPS. Optimum conditions for the preconcentration and separation of the target adenosines were also investigated. Under the optimum conditions, we obtained acceptable linearities in the range of 0.05?10 μg mL-1 and the LOD calculated within the range of 0.036?0.039 μg mL-1. The RSD values based on the intensity of six replicate determinations for ATP, ADP, and AMP were determined to be 4.5, 7.9, and 8.6%, respectively. This method is rapid, simple, practical, and suitable for the determination of the ATP, ADP, and AMP in royal jelly samples.3. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) modified with a new supramolecular macrocycle, carboxylatopillar[5]arene, was successfully prepared inside a capillary. The functionalized polymer monolith material was characterized bySEM, XPS, TGA, and FT-IR. The experimental results showed that this type of polymer possess a good network skeleton structure and excellent extraction properties for the enrichment of parabens by PMME-HPLC. Compared with other pre-treatment methods, the simple operation and inexpensive instrumentation characteristics of the developed PMME-HPLC method make it more suitable for the extraction of parabens in red wine samples with great potential for further broadening its applications in the enrichment of other real samples.4. We synthesized graphene oxide(GO) functionalized surface-imprinted polymer based on the self-polymerization of dopamine to generate the imprinted cavity. Using minocycline as the template molecule, effects of experimental conditions in the imprinting procedure such as γ-MAPS@GO percentage, template concentration, and self-polymerization time of dopamine on the selectivity and performance of the prepared molecularly imprinted polymers were investigated. The characteristics of the prepared surface-imprinted polymer were determined by SEM,transmission electron microscope(TEM), energy dispersive spectroscopy(EDS),FT-IR, XPS, TGA, atomic force microscope(AFM), and water contact angle. The prepared GO functionalized surface-imprinted polymer showed good recognition capacity and enrichment performance for tetracycline antibiotics(TCs) and was successfully applied to the detection of the target analytes in milk samples. |
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