L-肉碱分子表面印迹聚合物的制备及其识别性能研究

以L-肉碱(L-carnitine)作为印迹模板分子,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,采用硅胶表面分子印迹技术合成了L-肉碱分子印迹聚合物(MIP)和非印迹聚合物(NMIP).通过紫外光谱研究了MAA与L-肉碱之间的结合作用.利用IR和SEM测试分别对产物进行了结构表征和表面形貌观察,说明分子印迹聚合物成功接枝到了硅胶表面.吸附动力学实验结果表明,MIP对L-肉碱有较好的识别性和吸附性;Scatchard分析表明该印迹聚合物中存在着一类等价的结合位点,最大表观结合量为71.00μmol/g,离解常数Kd=2.76×10-4mol/L;选择性吸附实验结果表明,MIP对L-肉碱的吸附结合量高于其D型异构体和其他类似物;拆分实验结果表明,MIP对DL-肉碱的拆分有一定作用.     

香豆素分子模板聚合物的合成与性能研究

以香豆素为模板分子, α-甲基丙烯酸(MAA)、丙烯酰胺(MA)、2-乙烯基吡啶(2-VP)和4-乙烯基吡啶(4-VP)为功能单体, 二甲基丙烯酸乙二醇酯(EGDMA)为交联剂, 利用分子模板技术分别在甲苯、甲醇、氯仿和乙腈溶剂中合成了一系列香豆素分子模板聚合物(MTP), 研究了聚合体系组成对模板聚合物吸附特性的影响. 结果表明, 在所合成的模板聚合物中, 以MAA为功能单体, 乙腈为致孔溶剂, 以1∶4∶30的摩尔比加入模板分子、MAA及EGDMA时制备的模板聚合物吸附容量高、印迹效果和选择性好. 此模板聚合物有作为白芷样品中香豆素吸附分离材料的应用前景.     

林可霉素分子印迹聚合物的制备及吸附性能研究

以林可霉素(LIN)为模板,利用分子模拟方法模拟丙烯酰胺(AM)、甲基丙烯酸(MAA)、2-乙烯基吡啶(2-VP)和4-乙烯基吡啶(4-VP)4种常见的功能单体与模板分子的结合能,结果表明4-VP结合能最强为-98.25 kJ/mol。用悬浮聚合法制备林可霉素分子印迹聚合物(MIP)并对其性能进行评价。使用气相色谱检测各功能单体制备的印迹聚合物的吸附量,结果4-VP制备的印迹聚合物吸附量最大为102.8μmol/g,分子模拟结果与吸附试验结果一致,表明分子模拟可以为功能单体选择提供依据。采用静态吸附试验和动态吸附试验对印迹聚合物吸附性能表征,并进行了Scatchard模型分析。结果印迹因子为2.54,并且在150 min内较快地达到吸附平衡,表明林可霉素分子印迹聚合物具有较高的选择吸附性,可用于林可霉素的富集。     

克百威分子印迹聚合物的合成及其性能评价

以克百威为模板分子,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,采用沉淀聚合的方法制备了克百威分子印迹聚合物。通过红外光谱分析得到模板和功能单体的最佳配比为n(carbofuran)∶n(MAA)=1∶6。印迹聚合物的红外光谱测定结果表明,聚合物中存在与模板分子相互作用的特征基团;从印迹聚合物的扫描电镜图观察到分子印迹聚合物(MIP)与空白聚合物(NIP)的表面形态不同,可推论MIP存在与模板分子相互识别的结合位点。通过静态平衡结合法研究了模板分子聚合物的吸附能力、结合动力学和选择特性。结果表明,与非印迹聚合物相比,印迹聚合物对克百威具有较强的吸附特性和很好的专一选择性,3h后基本达到最大吸附量。采用固相萃取柱预处理样品,用高效液相色谱法测定自来水中10、50、100mg/L克百威的加标回收率为94%～117%,相对标准偏差(n=3)为2.5%～4.7%。     

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。     

介孔印迹聚合物的制备及固相萃取黄花蒿中的青蒿素

制备了一种基于分子印迹聚合物(MIP)的固相萃取填料,用于中草药黄花蒿中青蒿素(ARS)的分离纯化。采用青蒿素为模板分子,丙烯酰胺(AM)、甲基丙烯酸(MAA)为双功能单体,介孔材料(MCM-41型)为载体,表面印迹法制备ARS分子印迹聚合物。通过傅里叶变换红外光谱(FTIR)、透射电镜(TEM)、N_2吸附(BET)法对聚合物进行了表征,聚合物具有规则的形貌,较大的比表面积;动力学吸附和选择性吸附实验对MIP的吸附性能进行评价,结果表明,聚合物对青蒿素具有较高的吸附量(102.25 mg/g);能够快速达到吸附平衡(35 min);该聚合物为青蒿素的分离、富集提供一种新材料。     

非诺贝特印迹聚合物的制备与性能研究

以非诺贝特(FNB)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FNB分子印迹聚合物(MIP)。IR和SEM表征的结果显示:FNB分子印迹聚合物中存在与模板分子相互作用的特征基团,与空白聚合物(NIP)的表面形态显著不同,说明MIP存在与模板分子相互识别的结合位点。采用静态平衡结合方法和Scatchard模型评价了FNB分子印迹聚合物的结合特性和识别机理,并考察了其选择性吸附能力。结果表明,FNB分子印迹聚合物存在能量相异的两类特异性结合位点,对FNB具有高选择吸附特性,饱和吸附量为6.363mg/g。     

青霉素V钾分子印迹聚合物的制备及性能研究

以α-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,偶氮二异丁腈(AIBN)为引发剂,β-内酰胺类抗生素青霉素V钾为模板,制备了分子印迹聚合物(MIP),通过紫外吸收光谱法研究发现模板分子与单体之间产生了氢键相互作用,二者的结合常数为2.889×109L3/mol3,化学配位比为3。通过吸附实验,探讨了印迹聚合物对模板分子的识别特性,结果印迹因子为2.31,最大表观结合量为8.63μg·mg-1,表明MIP对模板青霉素V钾有较强的特异识别性,为进一步将其应用于实际样品中抗生素的残留分析奠定了基础。     

邻苯二甲酸二甲酯印迹吸附材料的水相合成及固相萃取应用

在硅胶表面以邻苯二甲酸二甲酯(DMP)为模板分子,甲基丙烯酰胺(MAM)为功能单体,N,N-亚甲基双丙烯酰胺(MBAA)为交联剂在甲醇/水体系中制备了DMP印迹聚合物。采用紫外光谱法(UV)研究单体与模板间的相互作用,红外光谱分析印迹聚合物的结构特征。用平衡吸附实验方法研究聚合物对DMP的结合性能,Scatchard法分析聚合物的吸附解离常数(Kd)和最大表观吸附容量(Qmax)。对不同底物的选择性实验表明聚合物对模板分子具有良好的亲和性和选择性。将MIP用作固相萃取(SPE)柱填料,对环境水样中的DMP进行富集试验,回收率为90.28-95.25%,相对标准偏差(RSD)为3.52-7.61%。     

氧化石墨烯表面坐果安分子印迹聚合物的合成及其表征

以氧化石墨烯为载体,坐果安为模板分子,α-甲基丙烯酸(MAA)为功能单体,采用表面分子印迹技术制备了坐果安分子印迹聚合物微球。利用紫外光谱和扫描电镜等对聚合物进行表征,研究聚合物的结合和识别特性。通过静态平衡结合法研究了吸附时间、温度、pH和底物初始浓度对其吸附性能的影响,并考察了其重复利用性。通过Scatchard分析研究了聚合物的结合特征,最大表现结合量(Q_(max))为114.902μg/mg,其表明聚合物对坐果安分子具有优良的选择吸附性能和较高的吸附容量。     

Synthesis of molecularly imprinted polymers for the application of selective clean-up vinblastine from Catharanthus roseus extract

Molecularly imprinted polymers (MIPs) are synthetic tailor-made polymers with high selectivity towards a particular substance (template). An MIP using vinblastine (VLB) as the template molecule was synthesized and characterized. The presence of monomer-template complexes in a non-covalent way was confirmed by UV-vis spectrometry analysis. The polymerization was performed using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, and toluene as the porogenic solvent by a thermo-polymerization method. The characterization of the obtained MIP was evaluated by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. It was observed that the morphology of the MIP was more porous and rough, and the surface area had a significant increase compared with that of the non-imprinted polymer (NIP). This MIP was used as the sorbents of solid-phase extraction (SPE) to assess the selectivity of the MIP after optimization of the SPE protocol. VLB was specifically adsorbed on the MIP cartridge, while to vincristine (VCR), the chemical analog of VLB, almost no selective binding appeared. On the basis of the results, Catharanthus roseus extract was applied to the MIP cartridge for investigating its capability to extract VLB from the plant extract, and the capacity of the MIP cartridge was also evaluated. It was shown that the MIP could effectively enrich VLB from C. roseus extract and the recovery amounted to 93.8%. The solvents dissolving the samples had significant influence on the capacity of the MIP cartridge; it was 750 μg/g in toluene, 625 μg/g in chloroform, and 250 μg/g in methanol.     

Optimization of the process parameters of synthesis of vinblastine imprinted polymer

Molecularly imprinted polymers (MIPs) are tailor-made polymers with high selectivity for the template molecule. This selectivity arises from the synthetic procedure followed to prepare the MIP. In this work, the influence of process parameters on the preparation of vinblastine (VLB) imprinted polymers was presented. In the procedure of polymerization, VLB (0.1 mmol) was used as the template molecule and a commonly used initiator, azobisisobutyronitrile (AIBN), was employed to initiate the reaction at 60 °C. The influence of the following parameters was investigated: the moles of functional monomer (MAA, 0.3-1.0 mmol), the moles of cross-linker (EDMA, 1.5-5.0 mmol) and the porogenic solvent (toluene or acetonitrile). A mathematical method of uniform design was applied to optimize these selected parameters in order to increase the selectivity of MIP for template molecule. The experimental data were analyzed to obtain the regression model and the optimal conditions were achieved by optimization with uniform design software. The MIP was synthesized under the optimal conditions that 1.0 mmol of MAA and 5.0 mmol of EDMA copolymerized in toluene in the presence of 0.1 mmol of VLB. After removal of the template molecule, the obtained MIP was then employed as the sorbents of solid-phase extraction (SPE) to separate VLB from Catharanthus roseus extract. The results showed that the polymer exhibited high affinity to the template molecule and could separate and enrich VLB from C. roseus extract effectively. The recovery of VLB on the optimal MIP was 89.00%, which agreed closely with the predicted recovery. Therefore it is possible to further improve the nature of the polymer by optimizing the polymerization parameters with the method of uniform design.     

橄榄醇分子印迹聚合物的制备及评价(英文)

以橄榄醇为模板分子,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,甲苯和十二醇为溶剂,通过本体聚合法制备了橄榄醇分子印迹聚合物。利用平衡结合实验、扫描电镜(SEM)及红外光谱(FTIR)对分子印迹聚合物(MIP)进行了表征,并用该聚合物进行了加标麦麸中橄榄醇的固相萃取(SPE)研究。平衡结合实验表明MIP对模板分子具有更好的识别性。Scatchard分析表明对橄榄醇分子的吸附存在2类不同结合位点,其中高亲和力结合位点和低亲和力结合位点的解离常数分别为0.021和1.002 mmol/L,相应的最大表观结合量分别为18.74和135.9 μmol/g。在优化的固相萃取条件下,MIP固相萃取柱对加标麦麸中橄榄醇的回收率达到97.8%~98.8%,相对标准偏差为2.8%~4.2%(n=5),线性范围为0.1~100 mg/L,检出限(S/N=3)为0.062 mg/L。与非印迹聚合物(NIP)柱及市售聚苯乙烯/二乙烯基苯(PLS)柱相比,MIP柱的选择性更强,回收率更高,纯化效果更好。     

Development of andrographolide molecularly imprinted polymer for solid-phase extraction

A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C(18)-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata (Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9±0.6 μmol/g and 12.1±0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n=5) and 96.0% and 104.2% (RSD 2.9-3.7%, n=5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.     

Selective trace enrichment of acidic pharmaceuticals in real water and sediment samples based on solid-phase extraction using multi-templates molecularly imprinted polymers

A novel multi-templates molecularly imprinted polymer (MIP), using acidic pharmaceuticals mixture (ibuprofen (IBP), naproxen (NPX), ketoprofen (KEP), diclofenac (DFC), and clofibric acid (CA)) as the template, was prepared as solid-phase extraction (SPE) material for the quantitative enrichment of acidic pharmaceuticals in environmental samples and off-line coupled with liquid chromatography–mass spectrometry (LC/MS/MS). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. When 1 L of water sample spiked at 1 μg/L was loaded onto the cartridge, the binding capacity of the MIP cartridge were 48.7 μg/g for KEP, 60.7 μg/g for NPX, 52 μg/g for CA, 61.3 μg/g for DFC and 60.7 μg/g for IBP, respectively, which are higher than those of the commercial single template MIP in organic medium (e.g. toluene) reported in the literature. Recoveries of the five acidic pharmaceuticals extracted from 1 L of real water samples such as lake water and wastewater spiked at 1 μg/L were more than 95%. The recoveries of acidic pharmaceuticals extracted from 10-g sediment sample spiked at the 10 ng/g level were in the range of 77.4–90.6%. To demonstrate the potential of the MIP obtained, a comparison with commercial C18 SPE cartridge was performed. Molecularly imprinted solid-phase extraction (MISPE) cartridge showed higher recoveries than commercial C18 SPE cartridge for acidic pharmaceuticals. These results showed the suitability of the MISPE method for the selective extraction of a group of structurally related compounds such as acidic pharmaceuticals.     

咖啡因分子印迹固相萃取柱的制备及应用

以咖啡因作为模板分子,α-甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,制备了咖啡因分子印迹聚合物(MIP)。与非印迹聚合物(NIP)相比,MIP对咖啡因具有更高的吸附容量和选择性,MIP和NIP对咖啡因的最大静态吸附量分别为28.1和16.5mg/g,相对选择因子为1.25。以咖啡因分子印迹聚合物为固相萃取填料,结合高效液相色谱(HPLC),建立了茶水中咖啡因浓度及人饮茶后血清中咖啡因浓度的检测方法。考察了洗脱剂种类和用量对咖啡因回收率的影响。当萃取柱依次以2mL水活化,水溶液上样,2mL水淋洗,6mL甲醇-乙酸(9∶1,V/V)洗脱,咖啡因在MIP固相萃取柱上的回收率达到97.5%,而在NIP柱上的回收率仅为54.9%。     

Direct determination of ciprofloxacin by mass spectrometry after a two-step solid-phase extraction using a molecularly imprinted polymer

A molecularly imprinted polymer (MIP) has been prepared for the first time with ciprofloxacin (CIPRO) as the template molecule, via a noncovalent synthetic procedure. Prior to its use as a sorbent in SPE, the MIP was evaluated chromatographically to confirm that it was indeed molecularly imprinted. The MIP was then used to extract CIPRO selectively from urine samples by means of a two-step SPE procedure in which a commercial Oasis cartridge and a molecularly imprinted SPE cartridge were combined in series. This approach allowed the matrix compounds present in the samples to be removed effectively. The urine extracts obtained after this two-step SPE procedure was applied were relatively clean compared to the original samples, and this made it possible to inject directly the extracts into a mass spectrometer and thus quantify CIPRO in urine samples at low levels and reduce the time of analysis.     

气相色谱-质谱法测定植物源性食品中残留的联苯菊酯

建立了气相色谱-质谱检测8种植物源性食品中联苯菊酯残留量的方法。粮谷类样品采用乙腈提取、凝胶渗透色谱（GPC）结合Florisil固相萃取柱净化;蔬菜类样品采用乙酸乙酯提取、Florisil固相萃取柱净化,然后采用气相色谱-质谱测定,选择离子监测模式检测。方法的检出限为5 μg/kg（S/N=10）;在0.005～0.5 mg/L范围内呈现良好的线性关系,相关系数为0.9999;在0.005,0.04和0.1 mg/kg 3个添加水平下,联苯菊酯的添加回收率在74%～99%之间,相对标准偏差(RSD)小于13%。该方法灵敏度高,净化效果良好,能有效地消除复杂基质带来的干扰,可以作为日常样品中联苯菊酯残留量的检测和确证方法。     

Solid-phase extraction using molecularly imprinted polymers for selective extraction of a mycotoxin in cereals

The aim of this work was to develop a method for the clean-up of a mycotoxin, i.e. Ochratoxin A (OTA), from cereal extracts employing a new molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) and to compare with an immunoaffinity column. A first series of experiments was carried out in pure solvents to estimate the potential of the imprinted sorbent in terms of selectivity studying the retention of OTA on the MIP and on a non-imprinted polymer using conventional crushed monolith. The selectivity of the MIP was also checked by its application to wheat extracts. Then, after this feasibility study, two different formats of MIP: crushed monolith and micro-beads were evaluated and compared. Therefore an optimization procedure was applied to the selective extraction from wheat using the MIP beads. The whole procedure was validated by applying it to wheat extract spiked by OTA at different concentration levels and then to a certified contaminated wheat sample. Recoveries close to 100% were obtained. The high selectivity brought by the MIP was compared to the selectivity by an immunoaffinity cartridge for the clean-up of the same wheat sample. The study of capacity of both showed a significant higher capacity of the MIP.     

Selective extraction of derivates of p-hydroxy-benzoic acid from plant material by using a molecularly imprinted polymer

Selective SPE of derivates of p-hydroxybenzoic acid (pHBA) from plant extract of Melissa officinalis is presented using a molecularly imprinted polymer (MIP) made with protocatechuic acid (PA) as template molecule. MIP was prepared with acrylamide as functional monomer, ethylene glycol dimethacrylate as crosslinking monomer and ACN as porogen. MIP was evaluated towards six phenolic acids: PA, gallic acid, pHBA, vanillic acid (VA), gentisic acid (GeA) and syringic acid (SyrA), and then steps of molecularly imprinted SPE (MISPE) procedure were optimized. The best specific binding capacity of MIP was obtained for PA in ACN (34.7 microg/g of MIP). Other tested acids were also bound on MIP if they were dissolved in this solvent. ACN was chosen as solvent for sample application. M. officinalis was extracted into methanol/water (4:1, v/v), the extract was then evaporated to dryness and dissolved in ACN before application on MIP. Water and ACN were used as washing solvents and elution of benzoic acids was performed by means of a mixture methanol/acetic acid (9:1, v/v). pHBA, GA, PA and VA were extracted with recoveries of 56.3-82.1% using this MISPE method. GeA was not determined in plant extract.