【作者】 朱秋劲；

【导师】 汤坚；

【作者基本信息】 江南大学 ， 食品营养与安全， 2007， 博士

【摘要】 分子印迹聚合物(MIP)属于功能性的高分子聚合物,对印迹分子有专一性识别位点以及对结构相似化合物具有一定的识别作用。成为一种快速、简便和有效的生物样品预处理方法,是促进现代仪器分析效能增益的热点研究技术。本课题研究了以加热及紫外光两种引发模式,分别以17β-雌二醇为主和雄烯二酮为辅作为模板分子,三羟甲基丙烷三甲基丙烯酸酯为交联剂,在逐一分析七种不同单体对模板分子结合作用以及乙腈和甲醇等致孔溶剂影响的基础上进行沉淀聚合,得到了不同的分子印迹聚合物和它们的非分子印迹聚合物对照。应用红外光谱、固相核磁、高效液相、气质联用、扫描电镜、激光粒度测定、原子力显微、差示量热、热重分析、固相萃取、固相微萃取技术和吸附动力学、热力学等方法对这些高分子聚合物外观形态学特征,以及对这些分子印迹聚合物与17β-雌二醇、17α-雌二醇、雄烯二酮和孕酮四种甾醇类性激素选择性识别、富集性能进行表征。并针对三氟甲基丙烯酸与三羟甲基丙烷三甲基丙烯酸酯的聚合物(TFMAA-co-TRIM)不同聚合阶段的红外谱图的变化、两种比例(1/4和1/8)的17β-雌二醇与三氟甲基丙烯酸分子印迹聚合物的串联柱色谱表征、TFMAA-co-TRIM分子印迹聚合物识别甾醇化合物的热力学特征、特异性吸附孕酮和富集甾醇化合物的分子印迹固相萃取洗脱程序等做了专门的研究。通过研究阐明:紫外聚合产物TFMAA-co-TRIM中的νO-H振动吸收峰在聚合16h后红移,νC=O振动吸收峰在聚合24h后红移;TFMAA-co-TRIM对雌二醇异构体的印迹因子(IF)达到了3.01,α为2.28,优于其它功能单体参与得到的聚合物识别特性;TFMAA-co-TRIM聚合物粒径介于300 nm至1.5μm之间,作为色谱固定相具有良好的通量和低的柱压;在乙腈流动相中,TFMAA-co-TRIM分子印迹固定相的分离过程主要被焓驱动,低温有利于分子印迹固定相分离甾醇结构类似物;TFMAA-co-TRIM分子印迹聚合物在255.84℃时开始熔融,Tp=257.40℃,聚合物CP的降解温度在267.79℃,MIP降解温度在343.11℃,制备的固相微萃取头初步经GC/MS 270℃的耐热性测定;不同的洗提溶剂筛选证明了选择接近聚合溶剂的洗脱体系更有利于MISPE发挥识别效应;分子印迹固相萃取柱(MISPE)对孕酮、17α-雌二醇、17β-雌二醇和雄烯二酮都具有不同程度的保留特性,可作为此类化合物的吸附材料,特别对孕酮强保留的富集特性,可作为孕酮的选择性识别吸附剂,其分子印迹聚合物对17β-雌二醇的吸附动力学测定显示在50 min内基本达到吸附平衡,具有作为传感器核心敏感材料的潜力;对比萃取奶粉中17β-雌二醇性能,MISPE柱比非分子印迹固相萃取柱(CSPE)和C18柱具有更高的保留,回收率依次为85.5%,43.7%和30.7%。以上研究展示了TFMAA-co-TRIM分子印迹聚合物的应用前景,并为开发甾醇化合物仿生传感器技术奠定了基础。更多还原

【Abstract】 Molecularly imprinted polymer belongs to functional high molecule polymer with specific recognition site for template and partial binding for structure analogues. At present, molecularly imprinted technology has borne a focus on developing a fast, simple and effective pre-preparation method for bio-sample in order to promote performance of model analysis instrument.In this dissertation, synthesis of molecularly imprinted polymer and non-molecularly imprinted polymer were based on for investigation of the interaction of seven different monomers with templates. 17β-estradiol and 4-androstene-3, 17-dione were used as templates, trimethylolpropane trimethacrylate was used as a cross-linker and two initiation modes of heat-polymerization and photo-polymerization were adopted. At last, the polymerization was implemented according to precipitation polymerization method. Morphologic appearance of molecularly imprinted polymer was measured by Laser Particle Analysis, Scan Electron Microscope and Atomic Force Microscope. Polymer selectivity recognition and enrichment properties with 17β-estradiol, 17α-estradiol, progesterone and 4-androstene-3, 17-dione were characterized through application of Fourier Transform Infrared Spectroscopy, Solid Phase Nuclear Magnetic Resonance, High Performance Liquid Chromatography, Gas-liquid Chromatograph-Mass Spectroscopy, Differential Scanning Calorimeter, Thermo gravimetric Analysis, Solid Phase Extraction and Solid Phase Micro-Extraction. In addition, adsorption kinetics and thermodynamics were adopted for revealing sorbent temperament.Several experiments were specially designed in the study. Changes in different polymerization stages of TFMAA-co-TRIM was detected by Fourier Transform Infrared Spectroscopy. Two columns loaded with MIPs from various rates of 17β-estradiol vs. trifluoromethyl acrylic acid (1/4 and 1/8) were tandem linked for improving separation characteristics. Recognition principle MIP of TFMAA-co-TRIM for sterol compounds was revealed by thermodynamics means. Elution files for specific adsorption of progesterone and enrichment of sterol compounds were arduously screened out from a mass of chemical reagents.The conclusions were as follows: theνO-H andνC=O IR absorption maxima shifted towards higher wave numbers after imprinting 17β-estradiol on TFMAA-co-TRIM copolymer with the red shift of theνO-H groups being apparent after precipitation polymerization for 16h while that forνC=O groups being observed after polymerization for 24h. A strong interaction between TFMAA and 17β-estradiol was confirmed by the high selectivity for 17β-estradiol, as indicted by the values of the separation factor (α) of isomers of 17β-estradiol/17α-estradiol (2.28) and the imprinted factor (IF) (3.01). Particle diameter of TFMAA-co-TRIM polymer was between 300 nm and 1.5μm, which suited well for solid phase sorbent throughout at low column pressure. The recognition of imprinting TFMAA-co-TRIM polymer for sterol molecules was driven by enthalpy eluted with acetronitile, and low temperature was in favor of the separation of sterol structure analogues on imprinting column. TFMAA-co-TRIM polymer possessed of determinate anti-heat stability, with melting point beginning at 255.84℃, Tp=257.40℃, control TFMAA-co-TRIM polymer and imprinting TFMAA-co-TRIM polymer were respectively decompounded at 267.79℃and 343.11℃, and solid micro-extraction noddle prepared by the special polymerization also showed definite recognition for 17β-estradiol by GC/MS detecting at 270℃. By selection of various washing and elution solvents, elution reagents of close polymerization system were of more advantage in template molecules retention and recognition on molecularly imprinted solid phase extraction (MISPE) column. At a certain extent, progesterone, 17α-estradiol, 17β-estradiol and 4-androstene-3, 17-dione could be intercepted on the MISPE column. Especially, MISPE had high selectivity for progesterone, and imprinting TFMAA-co-TRIM polymer could achieve adsorption balance within 50 min by absorption kinetics test for 17β-estradiol. However, MISPE column showed better selectivity and enrichment property for 17β-estradiol than C18 and CSPE columns according to the data from HPLC and GC/MS analyses. Recovery of 17β-estradiol on MISPE column was up to 85.5% while when prime extracting solution of milk powder was sampled, the recovery of CSPE and C18 columns were 43.7% and 30.7%, respectively. Thus, the imprinting TFMAA-co-TRIM polymer should be used as specific sorbent of sterol judging from the results obtained with a potential predominance as a sensitive material for sensors.更多还原