活性自由基聚合法制备多壁碳纳米管表面槲皮素分子印迹聚合物及其应用

为了制备能有效分离富集药草中槲皮素的固相萃取柱,以丙烯酰胺(AM)修饰的碳纳米管为载体,三硫代碳酸酯(DBTTC)为可逆加成-断裂链转移剂(RAFT试剂),槲皮素为模板,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,乙腈为致孔剂,制备了槲皮素分子印迹聚合物,采用红外光谱、扫描电镜和热重分析对印迹材料进行表征,通过高效液相色谱(HPLC)研究聚合物的吸附性能和对底物的特异性识别能力。结果表明,通过活性自由基聚合法合成的多壁碳纳米管表面槲皮素分子印迹聚合具有更好的形态结构和吸附性能,且对槲皮素有很好的特异性识别能力。     

可逆加成-断裂链转移沉淀法制备孔雀石绿分子印迹材料及应用

采用可逆加成-断裂链转移(RAFT)技术结合分子印迹沉淀聚合法,以孔雀石绿(MG)为模板分子,以二苄基三硫代碳酸酯(DBTTC)为RAFT试剂,制备孔雀石绿分子印迹微球。通过电镜表征,考察溶剂及单体/AIBN/DBTTC的比例对聚合物的形貌的影响,并对其吸附性能进行研究。结果表明,优化条件后制得的聚合物微球粒径均一,分散性好,对目标分子有良好的特异识别性,且吸附量高于传统法。将其做为固相萃取填料,结合高效液相色谱法对小龙虾及养殖水中MG进行分离,富集,检测。方法回收率为77.3%~100.6%,RSD5.1%,检出限为0.37μg/L。     

基于活性自由基聚合的槲皮素分子印迹聚合物的合成及在维药祖卡木颗粒活性成分分析中的应用

以二苄基三硫代碳酸酯(DBTTC)为可逆加成-断裂链转移剂(RAFT试剂),槲皮素(Quercetin)为印迹化合物,分别以甲基丙烯酸(MAA)、丙烯酰胺(AM)、丙烯酸(AA)、4-乙烯基吡啶(4-VP)和2-乙烯基吡啶(2-VP)作为功能单体,利用可逆加成-断裂链转移自由基聚合法制备了槲皮素分子印迹聚合物.实验考察了不同的制备条件,利用氮吸附测试及扫描电子显微镜对聚合物的结构进行了测定,采用色谱法对印迹聚合物的识别能力及分离效率进行了评价.研究了聚合条件-聚合物结构-分离效率的关系,探讨了利用活性自由基合成分子印迹聚合物的方法及特点;并将合成的分子印迹聚合物用作固定相,对维药祖卡木颗粒中的槲皮素进行了分离富集.研究结果表明,通过活性自由基聚合法合成的分子印迹聚合物具有更好的形态结构,对目标分子具有很好的吸附效率.     

氨苄西林分子印迹材料的制备及应用

以氨苄西林为模板分子,二苄基三硫代碳酸酯(DBTTC)为链转移试剂,采用可逆加成-断裂链转移(RAFT)沉淀聚合法,制备分子印迹聚合物。通过光谱法和电镜表征,分别对功能单体及交联剂进行选择。采用吸附实验对其性能进行研究。结果表明,以优化条件制得的聚合物微球粒径均一,分散性好,并对氨苄西林具有良好的吸附性能,最大吸附量为55. 7mg·g-1。将其做为固相萃取填料,结合高效液相色谱法对猪肾、牛奶和鸡肉中氨苄西林进行分离检测,回收率为78. 7%～97. 3%,RSD≤4. 1%。     

活性/可控自由基聚合制备奎宁分子印迹微球及识别性能研究

以奎宁分子为模板,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,二硫代四乙基秋兰姆(TED)为活性/可控引发剂,将可逆加成—断裂链转移自由基聚合与沉淀聚合相结合,制备微米级的球形奎宁分子印迹聚合物。并用扫描电镜和激光粒度扫描对聚合物粒子进行表征,结果显示,活性/可控聚合制备的分子印迹聚合物呈均匀的球形,其平均粒径最大可达2.3μm。对不同底物的结合实验表明,与传统沉淀聚合物相比,该分子印迹聚合物表现出更高的络合容量和分子选择性。     

三聚氰胺分子印迹整体柱识别性能的研究

以三聚氰胺(MAM)为模板分子,甲基丙烯酸(MAA)为功能单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,原位聚合法制备了对MAM有很强选择性识别能力的分子印迹整体柱。采用脉冲洗脱法快速筛选MAM的洗脱剂,通过前沿色谱法测定了整体柱对MAM的结合容量。实验表明,所制备的印迹整体柱对MAM有极强亲和作用力,即使在强极性流动相中(甲醇或甲醇-水(V/V=80/20)),MAM在印迹柱上也有强保留,不被洗脱。实验测得结合位点数(Lt)和解离常数(Kd)分别为:印迹柱Lt=2.28×103μmol/g,Kd=2.45×10-5mol/L;空白柱Lt=366μmol/g,Kd=23.7mo/L。该印迹整体柱有望作为固相萃取柱,在线或离线选择性富集样品中的MAM。     

对苯二胺分子印迹聚合物的分子识别特性

以对苯二胺(p-PD)为模板分子,分别以甲基丙烯酸(MAA)和丙烯酰胺(AA)为功能单体,制备了p-PD的印迹聚合物P(MAA)和P(AA),采用色谱法考察了其分子识别特性。结果表明,P(AA)对p-PD无明显的印迹效应;而甲醇为流动相时,P(MAA)能够选择性结合p-PD分子(k′=3.57),对p-PD有显著的印迹效应(印迹因子IF=2.95),P(MAA)柱可以实现p-PD与邻苯二胺(o-PD)和对氨基苯甲酸(p-ABA)的色谱分离。通过光谱实验及HF/6-31G*量化理论计算方法,对比研究了p-PD与MAA和AA之间的相互作用。MAA与p-PD能够形成更稳定的复合物,P(MAA)对p-PD具有更好的分子识别能力。研究表明紫外吸收光谱法和荧光光谱法以及量子化学理论计算法可作为功能单体筛选的有效手段;对于荧光模板分子,荧光光谱法具有简便、灵敏等特点。     

类模板分子印迹整体柱测定甲氧苄啶的研究

利用三聚氰胺(MAM)与甲氧苄啶(TMP)分子中嘧啶环局部结构类似的特性,以三聚氰胺为类模板分子,甲基丙烯酸(MAA)为功能单体,二甲基丙烯酸乙二醇酯(EDMA)为交联剂,原位聚合法制备了对甲氧苄啶(TMP)有识别作用的分子印迹(MIP)整体柱.在优化的色谱条件下,该印迹整体柱对甲氧苄啶显示出选择性识别作用,而对叶酸、...     

选择性富集分离虎杖中白藜芦醇苷的分子印迹聚合物的制备及分子识别性能研究

以白藜芦醇苷(POL)为模板分子,分别以丙烯酰胺(AM)、4-乙烯基吡啶(4-VP)、甲基丙烯酸羟乙酯(HEMA)、甲基丙烯酸(MAA)为功能单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用本体聚合法制备白藜芦醇苷分子印迹聚合物。采用静态平衡结合实验研究了印迹聚合物对模板分子及不同底物的识别性能。结果表明,以丙烯酰胺为功能单体的印迹聚合物(MIP1)对模板分子的识别性能最好,其次是以4-VP为功能单体的聚合物(MIP2),以HEMA为功能单体的聚合物(MIP3)以及以MAA为功能单体的聚合物(MIP4)的分子识别性能较差。表明功能单体与模板分子之间相互作用的强弱对MIP的识别能力有较大的影响。静态平衡结合法以及Scatchard分析法表明,MIP1对模板分子呈现较好的结合能力和选择性,该印迹聚合物中形成了2类不同的结合位点,离解常数分别为7.43×10-5、3.70×10-3mol/L。将MIP1用于虎杖提取物中POL的固相萃取分离,效果良好。     

可逆加成断裂链转移沉淀法制备烯唑醇分子印迹聚合物

以烯唑醇为模板分子，二苄基三硫代酯（DBTTC）为可逆加成一断裂链转移剂，采用RAFT-沉淀聚合方法制备分子印迹聚合物。通过紫外光谱法选择了功能单体,电镜分析对交联剂、DBTTC的用量进行筛选；并通过静态吸附实验、选择吸附实验对聚合物的吸附性能进行了研究，结果表明聚合物最大吸附量为39.60 mg/g，优于传统方法制备的聚合物。将其作为固相萃取填料，结合HPLC法应用于面粉中烯唑醇的富集和检测。检出限为1.92×10-3 mg/kg，定量限为6.41×10-3 mg/kg。     

1-氨基乙内酰脲分子印迹聚合物的制备和吸附性能研究

以1-氨基乙内酰脲(AHD)为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,采用本体聚合方法合成了分子印迹聚合物(M IP),考察了模板分子与功能单体不同比例下制备的M IP对模板分子的吸附性能。通过Scatchard分析,表明该印迹聚合物上存在一类等价的吸附位点,其结合位点的离解常数KD=4.33mmol/L。     

分子印迹整体柱在高效液相色谱和电色谱手性分离中的应用

在常规不锈钢色谱管中以甲基丙烯酸为功能单体,采用原位聚合法制备了(5S,11S)-特罗格尔碱(S-TB)的印迹整体柱。考察了流动相中添加不同量的醋酸和水对分离的影响,结合台阶梯度洗脱模式在S-TB整体柱上实现了对TB消旋体的快速分离。另外,以碱性单体2-二甲基乙基胺甲基丙烯酸酯(DAMA)为功能单体,在毛细管中采用原位聚合法制备了毛细管分子印迹整体柱,用于在毛细管电色谱（CEC）中对消旋体1,1′-联-2-萘酚(BNL)进行手性分离。结果表明,以AMA为功能单体可以制备其他酸性模板的分子印迹聚合物,从而扩大了分子印迹聚合物MIP）在CEC分离中的应用范围。     

三甲氧基苄啶分子印迹整体柱的制备及色谱性能

选择甲基丙烯酸为功能单体\, 甲基丙烯酸乙二醇双酯为交联剂, 制备了三甲氧基苄啶分子印迹整体柱, 对整体柱材料的形貌进行了表征, 并且研究了TMP和5种磺胺类药物在分子印迹整体柱上的色谱行为.     

Syntheses of steroid-based molecularly imprinted polymers and their molecular recognition study with spectrometric detection

Recognition of five steroid compounds, beta-estradiol, ethynylestradiol, estradiolbenzoate, testosterone and methyltestosterone were studied using a synthesized molecularly imprinted polymer (MIP). When beta-estradiol was used as the template molecule, the polymer was synthesized with methacrylic acid (MAA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linking agent through non-covalent interactions. It is found that the kind of porogen solvent and the polymerization conditions greatly affected the binding ability of a MIP to a certain molecule. Releasing of the template was performed by continuous extraction with methanol containing 10% acetic acid in a Soxhlet extractor. Our results indicated that such carefully synthesized MIP showed specific affinity toward beta-estradiol in the adsorption process.     

Carprofen-imprinted monolith prepared by reversible addition–fragmentation chain transfer polymerization in room temperature ionic liquids

To obtain fast separation, ionic liquids were used as porogens first in combination with reversible addition–fragmentation chain transfer (RAFT) polymerization to prepare a new type of molecularly imprinted polymer (MIP) monolith. The imprinted monolithic column was synthesized using a mixture of carprofen (template), 4-vinylpyridine, ethylene glycol dimethacrylate, [BMIM]BF₄, and chain transfer agent (CTA). Some polymerization factors, such as template-monomer molar ratio, the degree of crosslinking, the composition of the porogen, and the content of CTA, on the column efficiency and imprinting effect of the resulting MIP monolith were systematically investigated. Affinity screening of structurally similar compounds with the template can be achieved in 200 s on the MIP monolith due to high column efficiency (up to 12,070 plates/m) and good column permeability. Recognition mechanism of the imprinted monolith was also investigated.     

Metal ion mediated molecularly imprinted polymer for selective capturing antibiotics containing beta-diketone structure

A new molecularly imprinted polymer (MIP) targeting to quinolones (Qs) and tetracyclines (TCs) was synthesized using itaconic acid (ITA) and ciprofloxacin (CIP) as a functional monomer and template molecule, respectively. Factors affecting the overall performance of MIP were investigated, and the results showed that Fe(3+) ion play a vital role in the formation of MIP with high molecular imprinting effect. Meanwhile, the chelating ability of monomer, species of template molecule, as well as the molar ratio of monomer and template also contribute to the performance of the obtained MIP. Cyclic voltammetry verified that, with the participation of Fe(3+) ions, a ternary complex of ITA-Fe(3+)-CIP could be formed before polymerization. Compared with conventional MIP prepared from commonly used monomer, methacrylic acid (MAA), the new MIP show significantly enhanced molecular imprinting effect and higher capacity for specific adsorption of target compounds as revealed by static and dynamic binding experiments. The MIP was successfully used as solid-phase extraction (SPE) adsorbent for enriching a broad spectrum of antibiotics containing beta-diketone structure from surface water sample. HPLC detection showed that high recovery rate (78.6-113.6%) was found in these spiked antibiotics, whereas recovery rate for the non structurally related drugs, epinephrine (EP) and dopamine (DOPA), was very low (4.7-7.6%) on the MIP cartridges. The results demonstrate that the MIP prepared by the strategy proposed in this work, could specifically target to a series of structurally related antibiotics containing beta-diketone structure.     

Molecularly Imprinted Polymer Monolithic Column Separation of Isomers and Analogues of Vanillin by Capillary Electrochromatography

A vanillin imprinted capillary monolithic column was synthesized by in situ polymerization reaction using ethylene-glycol dimethacrylate as cross-linking monomer and methacrylic acid as functional monomer. Under the optimum conditions of capillary electrochromatography, this molecularly imprinted polymer （MIP）-based column showed high selectivity and could recognize not only template molecule vanillin but also positional isomer o-vanillin from their structural analogues.     

Chiral separation of 1,1'-bi-2-naphthol and its analogue on molecular imprinting monolithic columns by HPLC

Two molecular imprinting polymer (MIP) monolithic columns with (S)-(-)-1,1'-bi-2-naphthol and (R)-(+)-5,5',6,6',7,7',8,8'-octahydro-1,1'-bi-2-naphthol as the templating molecules, respectively, have been prepared by in situ polymerization using 4-vinylpyridine and ethylene dimethacrylate as functional monomer and cross-linker, respectively. The columns with good flow-through properties were obtained by changing the molar ratio of the functional monomer and the template molecule. The effects of mobile-phase composition on separation of enantiomers were systematically investigated. The results indicate that hydrophobic interaction in aqueous solution and hydrogen-bonding interaction in ACN between the enantiomers and polymers could play important roles in the retention and resolution. The effects of chromatographic conditions, such as flow rate, column temperature, sample loading, on the enantioseparation were also studied. Further, these two MIP columns show a cross-reactivity.     

Fabrication of the Monolithic Fiber for the Solid Phase Micro‐extraction of Malachite Green

A monolithic fiber of molecularly imprinted polymer (MIP) was prepared by in situ polymerization within the capillary with an inner diameter of 530 µm. It was carried out in 8 min by microwave irradiation using malachite green (MG) as a template molecule, α‐methacrylic acid (MAA) as a functional monomer, acetonitrile (ACN) as a porogenic solvent, ethylene dimethacrylate (EDMA) as a crosslinker, azodiiso‐butyronitrile (AIBN) as a thermal initiator. The resulted MIP fibers were pushed out from the capillary, eluted and inserted in the capillary again, which successfully used for the solid phase microextraction (SPME) procedure. The factors affecting the extraction of MG, such as the molar ratio of template/monomer (MG/MAA), concentration of NaCl, extraction and desorption time, and extraction and desorption solvents were investigated in detail. The selectivity of the MIP fibers was compared using MG analogues crystal violet (CV) and non‐analogue Sudan II. It was also employed for the pretreatment of trace MG in the fish feed followed by high‐performance liquid chromatography (HPLC) detection. Under the optimal conditions, the linear range of MG was 10‐600 μg/L, the detection limit (LOD) was 1.23 μg/L and the recovery of spiked fish feed sample was 88.7～113.9%.