Study On The Preparation Methods And Recognition Properties Of Fluoroquinolones-Molecularly Imprinted Sol-Gel Sorbents

The aim of this dissertation is to develop the molecular imprinting polymers(MIPs) for 6the absorption of fluoroquinolones in the preparation of aqueous system by the combination of sol-gel technique and molecular imprinting technique, which is in order to facilitate selective analysis of the actual samples in the water-phase system. The MIPs recognition properties for the target molecule were investigated by the static adsorption experiments, the maximal adsorption capacity and dissociation constant were calculated by the Scatchard equation. The new imprinting method based on hydrophobic interaction and ion-pairing interaction between the functional monomer and the template molecule were developed, and the synthesis method of organic-inorganic imprinted polymer hybrids having interpenetrating polymer networks structure was investigated. The lomefloxacin-MIPs were used to solid-phase extraction for pre-concentration and determination the lomefloxacin in milk combined with high-performance liquid chromatography technique. The thesis includes four chapters as follows:Chapter one:A review mainly introduce the principle of sol-gel molecular imprinting technique, the application in drugs, the application in drug of quinolones, as well as the prospect of the sol-gel molecular imprinting technique.Chapter two:A novel molecularly imprinting polymer was synthesized by combining molecular imprinting technique and sol-gel process with norfloxacin as template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilane as crosslinker, added methyltrimethoxysilane (MTMS) to increase hydrophobic interaction. The influence of MTMS and the pH of adsorption solution on recognition properties was investigated. The binding capacity was evaluated by static absorption experiment and Scatchard analysis,which showed that the dissociation constant (KD) and the maximum binding capacity(Qmax) were 124.1mg/L and 46.44 mg/g for high affinity binding site, and 27.2 mg/L and 44.48 mg/g for lower affinity binding site respectively.Chapter three:A molecularly imprinted solid-phase extraction sorbent was synthesized using lomefloxacin as template,3-aminopropyltriethoxysilane as functional monomer, and methyltrimethoxysilane as crosslinker, by sol-gel technique, adjust pH value of the reaction system, use ions pairing action to combine template and functional monomer. The reaction mechanism was reasoned by the infrared spectroscopy analysis, The adsorption capacity of the polymer was evaluated by the static absorption experiment. The lomefloxacin MIPs were used to solid-phase extraction for pre-concentration the rudimental lomefloxacin in milk, the average recovery was 71.1%.Chapter four:A novel organic-inorganic interpenetrating hybird sorbent was synthesized with ofloxacin as template methacryloxypropyltrimethoxysilane and methacrylic acid as functional monomer and tetraethoxysilane as crosslinker, azobisisbutyronitrile as initiator, the synthesis method of organic-inorganic imprinted polymer hybrids having interpenetrating polymer networks structure was developed. The binding capacity was evaluated by static adsorption experiment and Scatchard analysis,which showed that the dissociation constant(KD) and the maximum binding capacity(Qmax) were 51.11mg/L and 51.34mg/g for high affinity binding site, and 159.02 mg/L and 77.41 mg/g for lower affinity binding site,respectively.