罗丹明B分子印迹聚合物微球的合成及其在固相萃取中的应用

以罗丹明B为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用沉淀聚合法制备了罗丹明B分子印迹聚合物(MIP)微球,并用扫描电子显微镜表征。 采用紫外分光光度法测定了印迹分子罗丹明B与功能单体丙烯酰胺二者之间的结合常数(K=5.303×103 (mol/L)-1)和化学计量比(n=1)。 考察了沉淀剂的种类和用量对聚合物微球的影响。 将分子印迹聚合物微球应用于固相萃取材料自制固相萃取柱,从加标罗丹明B的红椒粉中萃取罗丹明B。 本文优化了固相萃取条件,高效液相色谱检测表明,在一定的萃取条件下,分子印迹聚合物对加标量为0.479 mg/kg的辣椒中罗丹明B的萃取加标回收率可达91.7％～103.5%。     

核-壳型苏丹红Ⅰ印迹聚合物微球制备及应用研究

以苏丹红Ⅰ为模板分子,苯基-三甲氧基硅烷(PTMOS)为功能单体,乙二醇二甲基丙烯酸酯(EGD-MA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用表面分子印迹技术,在自制的SiO2微球表面成功合成了对苏丹红Ⅰ具有良好选择识别性能的核-壳型印迹聚合物。采用红外光谱和扫描电子显微镜对分子印迹微球进行表征,结果表明该印迹聚合材料壳层厚度约为150 nm;采用静态吸附实验研究印迹材料对模板聚合物的吸附性能和选择特性,结果表明以PTMOS为功能单体的印迹聚合物对苏丹红Ⅰ具有优异的选择吸附性,其分离选择因子为2.62。在吸附过程中,模板分子苏丹红Ⅰ与印迹聚合物形成2种结合位点,2种结合位点的解离常数分别为2.30、10.78 mmol/L,最大表观结合量分别为27.40、128.53μmol/g。将该印迹聚合物作为固相萃取材料,对样品进行固相萃取,结合液相色谱技术成功用于辣椒油中苏丹红Ⅰ的测定。     

分子印迹固相萃取-高效液相色谱法测定食品中苏丹红Ⅰ-Ⅳ

以苏丹红Ⅰ为模板分子,甲基丙烯酸为功能单体合成了苏丹红分子印迹聚合物,作为固相萃取吸附剂,用于食品中苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ的测定。样品经乙腈提取,所得提取液分子印迹固相萃取柱,然后用乙醇-正己烷（1+1）溶液作洗脱剂将苏丹红洗下,收集洗出液供高效液相色谱测定。结果表明:聚合物对印迹分子具有很好的亲和性和特异选择性。方法的线性范围为0.5～15 mg·L^-1,检出限（3S/N）为4μg·kg^-1。以辣椒粉和辣椒酱为基体,在3个浓度水平下做加标回收试验,回收率在70.3%～85.5%之间,测定值的相对标准偏差（n=5）低于6.0%。     

齐多夫定替代模板分子印迹聚合物的制备及其在血清样品固相萃取中的应用

制备了齐多夫定(AZT)替代模板分子印迹聚合物(MIP)用于血清样品的前处理。利用计算机模拟选择最佳单体甲基丙烯酸和交联剂二乙烯基苯,用自制的替代模板(AZT酯化物)制备了AZT的MIP。将替代模板MIP作为固相萃取吸附剂,进行固相萃取并优化萃取条件。确定pH 7的KH2PO4缓冲溶液为上样溶剂,2%(V/V)乙腈/pH 7的KH2PO4缓冲溶液为淋洗剂,甲醇/乙酸(9:1,V/V)作为洗脱剂。渗漏实验结果显示齐多夫定MIP的吸附容量为9.10 mg/g,而非分子印迹聚合物(NIP)的吸附容量仅为1.77 mg/g。以AZT酯化物和拉米夫定为结构类似物,进行吸附实验,发现MIP具有高选择性。本文所制备的替代模板分子印迹聚合物在水溶液体系中表现出了很好的识别能力。血清样品经印迹聚合物固相萃取后,用高效液相色谱法测定,发现MIP萃取柱回收率为99.3%,NIP萃取柱仅为13.2%,说明替代模板MIP可用于血清样品中AZT的选择性分离富集,并可以避免模板渗漏。     

在线分子印迹-化学发光法对食品中苏丹红Ⅰ的测定

以苏丹红Ⅰ作模板分子,用悬浮聚合法制备出微米级苏丹红Ⅰ分子印迹聚合物并将其做成微固相萃取柱,直接安装在流动注射系统的八通阀上,对样品溶液中的苏丹红Ⅰ进行在线分离和富集;经甲醇和甲酸混合洗脱液（体积比2：1）在线洗脱后与酸性高锰酸钾发生化学发光反应。据此建立了在线分子印迹微固相萃取,高锰酸钾氧化苏丹红化学发光测定食品中苏丹红Ⅰ的新方法。结果表明,测定的苏丹红Ⅰ线性范围为1．0×10^-6～7．0×10^-4g／L,方法检出限（3仃）为3×10^-7g／L,11次平行测定1×10^-5g／L苏丹红Ⅰ溶液的化学发光强度相对标准偏差为2．0％。     

加替沙星分子印迹聚合物的制备及其应用

以加替沙星为模板分子,采用溶胶-凝胶分子印迹技术,合成具有分子识别作用的新型有机-无机杂化分子印迹聚合物,对其进行吸附性能研究证明了印迹聚合物对加替沙星的专一吸附性能。以该印迹聚合物为固相萃取材料填充固相萃取柱,优化固相萃取条件,结合超高效液相色谱法,对牛奶样品进行检测。建立了分子印迹固相萃取方法,分离富集并检测牛奶中的加替沙星,其回收率为79.87%,富集倍数为38,高于市售C18柱,具有一定的实际应用价值。     

替米考星分子印迹聚合物的制备及其固相萃取研究

以泰乐菌素为虚拟模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了对替米考星具有高选择性的分子印迹聚合物。考察了二甲基甲酰胺、甲醇、丙酮和氯仿4种致孔剂对合成聚合物性能的影响。通过正交实验优化的聚合配方为:1.0mmol泰乐菌素,8.0mmol甲基丙烯酸,20.0mmol乙二醇二甲基丙烯酸酯,6.0mL氯仿,20.0mg偶氮二异丁腈。研究了将该聚合物作为固相萃取填料分离、富集替米考星的萃取条件和萃取性能。当萃取柱依次用甲醇和水(pH9.0)活化,乙腈溶液上样,甲醇和氯仿分别洗涤,3mL氨化甲醇(95:5,V/V)洗脱时,替米考星在分子印迹固相萃取柱上的回收率达到90%以上,而非分子印迹固相萃取柱的回收率仅为32%。     

苏丹红I分子印迹聚合物的制备及其性能评价

以苏丹红I为模板分子,通过沉淀聚合法制备了一种对苏丹红I具有特异性吸附的分子印迹聚合物。通过选择性评价和前沿色谱实验,评价了致孔剂的选择和用量、功能单体和模板分子的物质的量比对分子印迹聚合物识别性能的影响。实验结果表明: 当以甲醇和乙腈的混合液(体积比为30:10)为致孔剂,甲基丙烯酸(MAA)为功能单体,且功能单体和模板分子的物质的量比为8:1时,分子印迹聚合物的印迹因子为2.32,亲和位点总数(Bt)为0.50 μmol/g;将其作为固相萃取柱填料用于辣椒粉样品中痕量苏丹红I的净化和富集,结果表明: 苏丹红I浓度在10～500 μmol/L范围内时,呈现良好的线性关系(r=0.999);检出限为3.3 μmol/L,加标回收率为95.87%～98.41%,相对标准偏差低于3.1%。该方法有望用于辣椒粉样品中苏丹红I添加剂的常规检测。     

聚合物整体柱固相萃取-高效液相色谱法同时测定食品中6种苏丹染料

以甲基丙烯酸丁酯为单体,乙二醇二甲基丙烯酸酯为交联剂,得到聚合物整体柱固相萃取小柱,将其用作固相萃取介质,结合高效液相色谱,分析测定辣椒粉和番茄酱中6种苏丹染料(对位红,苏丹I-IV和苏丹7B)。方法对6种苏丹染料在0.01~25μg/m L范围内呈良好线性关系,相关系数均高于0.9998。方法检出限为0.25~1.2μg/kg,在5,50和100μg/kg 3个加标浓度的平均回收率为80.5%~107.3%,相对标准偏差在5.3%~11%之间(n=6)。该整体柱对苏丹染料具有良好的净化和富集效果,同时,该萃取柱重现性良好,可以重复使用10次以上。     

尼泊金乙酯分子印迹固相萃取小柱的研制及应用

研制了一种对尼泊金乙酯具有特异性识别性能的分子印迹固相萃取小柱。用本体聚合法制备尼泊金乙酯分子印迹聚合物,通过静态平衡吸附实验及固相萃取实验表征其固相萃取性能,并结合UV法对滴眼液中的尼泊金乙酯进行测定。结果显示,尼泊金乙酯模板聚合物的吸附能力强于空白聚合物;印迹固相萃取柱对尼泊金乙酯标准溶液(0.04mmol/L)一...     

Use of polymeric sorbents for the off-line preconcentration of priority pollutant phenols from water for high-performance liquid chromatographic analysis

The use of porous polymeric minicolumns for the determination of phenols from the U.S. Environmental Priority Pollutant List was studied. For the off-line preconcentration of priority pollutant phenols from water by solid-phase extraction, minicolumns packed with 1,4-di(methacryloyloxymethyl)naphthalene-divinylbenzene copolymer and Amberlite XAD-4 were used. In order to compare the sorption properties of these polymeric sorbents, the recoveries and breakthrough volumes of phenol, p-nitrophenol, 2,4-dinitrophenol, o-chlorophenol, o-nitrophenol, 2,4-dimethylphenol, 4-chloro-m-cresol, 4,6-dinitro-o-cresol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol were studied.     

Development of miniaturized sample preparation with fibrous extraction media

Introducing fine polymeric filaments as the extraction medium, a miniaturized sample preparation technique for micro-column liquid chromatography (micro-LC) has been developed along with the investigation of a reproducible preparation scheme of the extraction capillary. The polymeric filaments were packed longitudinally into either a fused-silica capillary or a polyether ether ketone (PEEK) capillary of appropriate dimensions, and the extraction capillary was installed to the injection valve in micro-LC system. The number of packed filaments should be precisely counted before the packing process to make sure the reproducible preparation of the extraction capillary. With conventional stationary phase materials for open-tubular gas chromatography, polymeric coating to the surface of the filaments was also studied in order to further enhance the extraction performance and selectivity. Coated with the polymeric material suitable for the extraction of particular analyte, a dramatic improvement on the extraction power was obtained. The results suggest that the future possibility of novel tailored fibrous extraction medium with an appropriate coating on it, especially for the analysis of complex sample matrices.     

Surface-initiated molecularly imprinted polymeric column: In situ synthesis and application for semi-preparative separation by high performance liquid chromatography

In this work, we prepared a monolithic and surface initiated molecularly imprinted polymeric (MIP) column for HPLC and explored its application for template separation from plant extract. The silica beads (40-60 μm) were coupled with initiator on the surface and then packed in to a stainless steel HPLC column. The pre-polymerization mixture (the template, functional monomer and crosslinker were emodin, acrylamide and divinylbenzene, respectively) was injected into the column and polymerized by thermal initiation. The prepared MIP column exhibited excellent retention capability and large imprinted factor for template (the retention time and imprinted factor for emodin on MIP column were 16.26 min and 7.21, respectively). Moreover, the emodin-molecularly imprinted polymeric column could be applied to separate emodin from alcohol extract of Rheum palmatum L. at semi-preparative scale and 1.2 mg of emodin was obtained in 4 h.     

Quantitation of hyaluronic acid and chondroitin sulphates in rabbit synovial fluid by high-performance liquid chromatography of oligosaccharides enzymatically derived thereof

A high-performance liquid chromatographic (HPLC) method for quantifying unsaturated hexasaccharide and tetrasaccharide from Streptomyces hyaluronidase enzyme digestion products of hyaluronic acid was developed using a gel-permeation column packed with a sulphated polystyrene-divinylbenzene gel. For the oligosaccharides, the separation was accomplished in less than 7 min with a detection limit of 65 ng. An unsaturated non-sulphated disaccharide prepared from hyaluronic acid (delta Di-HA) and an unsaturated sulphated disaccharide (delta Di-4S) were analyzed by a HPLC method using a combination of two different gel-permeation columns. The separation of the disaccharides required less than 17 min at a flow rate of 0.7 ml/min with detection limits of as little as 4 ng for delta Di-HA and 5 ng for delta Di-4S. Both chromatographic methods were used for assay of a major component of hyaluronic acid and trace amounts of chondroitin sulphates in rabbit synovial fluid. The resulting contents of hyaluronic acid were compared to the values of polymeric hyaluronic acid directly measured by a HPLC method using two gel-permeation columns packed with a poly(hydroxyalkyl methacrylate) gel and the amounts of hyaluronic acid converted from uronic acid content determined by a colorimetric method.     

SYNTHESIS AND CRYSTAL STRUCTURE OF A POLYMERIC 1,2,4,5-BENZENETETRACARBOXYLATO COMPLEX OF Cu(II) WITH IMIDAZOLE,Cu2(C10H2O8)(C3H4N2)6(H2O)4 · 4H2O

Abstract

The title complex, Cu₂(C₁₀H₂O₈)(C₃H₄O₂)₆(H₂O)₄ · 4H₂O, consists of polymeric copper(II) complex anions and discrete copper(II) complex cations. Benzenetetracarboxyl anions bridge copper(II) atoms coordinated to water and imidazole groups to form the anionic polymeric chains along the a axis, while discrete copper(II) complex cations involving four imidazole and two water ligands are packed between parallel polymeric anionic chains, an extensive H-bonding network linking complex cations and anions.     

Chromatographic properties and polarity evaluation of poly(1-trimethylsilyl-1-propyne) and poly(1-phenyl-1-propyne)

The chromatographic properties of poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(1-phenyl-1-propyne) (PPP) were studied by gas chromatography using packed columns. The selectivity and efficiency of columns packed with PTMSP and PPP were compared to the data obtained for columns with other known adsorbents and stationary phases. The McReynolds and Rohrschneider constants, on the basis of which the polarity of the new phases was evaluated, were calculated. The results of the investigation of chromatographic properties allow PTMSP to be brought in line with the polymeric adsorbents Porapak Q, Porapak QS, and Chromosorb 106, while PPP, with the methyphenylsilicon phases SE-52 and OV-3.     

Rapid isolation of omega‐3 long‐chain polyunsaturated fatty acids using monolithic high performance liquid chromatography columns

Eicosapentaenoic and docosahexaenoic acids are important bio‐active fatty acids in fish oils. Monolithic HPLC columns both in the polymeric cation exchange (silver‐ion) and RP formats were compared with corresponding packed columns for the isolation of these acids from tuna oil ethyl esters. Monolithic columns in both formats enabled rapid (typically 5–10 min) separations compared with packed columns (30 min). Polymeric monolithic silver‐ion disc column rapidly furnished mixtures of eicosapentaenoic and docosahexaenoic esters (90% purity) within 5–10 min, but was unable to resolve individual esters. A preparative version of the same column (80 mL bed volume) enabled isolation (>88% purity) of 100 mg quantities of eicosapentaenoic and docosahexaenoic esters from esterified tuna oil within 6 min. Baseline separation of eicosapentaenoic and docosahexaenoic esters was achieved on all RP columns. The results show that there is potential to use polymeric monolithic cation exchange columns for scaled‐up preparation of eicosapentaenoic and docosahexaenoic ester concentrates from fish oils.     

Anion-exchange capillary electrochromatography with indirect UV and direct contactless conductivity detection

Conductivity detection is applied to ion-exchange capillary electrochromatography (IE-CEC) with a packed stationary phase, using a capacitively coupled contactless conductivity detector with detection occurring through the packed bed. Columns were packed with a polymeric latex-agglomerate anion-exchanger (Dionex AS9-SC). A systematic approach was used to determine suitable eluants for IE-CEC separations using simultaneous indirect UV and direct conductivity detection. Salicylate and p-toluenesulfonate were identified as potential eluant competing anions having sufficient eluotropic strength to induce changes in separation selectivity, but salicylate was found to be unsuitable with regard to baseline stability. It was also found for both indirect UV and direct conductivity detection that homogenous column packing was imperative, and monitoring of the baseline could be used to assess the homogeneity of the packed bed. Using a p-toluenesulfonate eluant, the separation of eight common anions was achieved in 2.5 min. Direct conductivity detection was found to be superior to indirect UV detection with regard to both baseline stability and detection sensitivity with detection limits of 4-25 microg/L being obtained. However, the calibration for each anion was not linear over more than one order of magnitude. When using conductivity detection, the concentration of the eluant could be varied over a wider range (2.5-50 mM p-toluenesulfonate) than was the case with indirect UV detection (2.5-10 mM), thereby allowing greater changes in separation selectivity to be achieved. By varying the concentration of p-toluenesulfonate in the eluant, the separation selectivity could be manipulated from being predominantly ion-exchange in nature (2.5 mM) to predominantly electrophoretic in nature (50 mM).     

Repeatability and reproducibility of retention data and band profiles on reversed-phase liquid chromatography columns. V. Results obtained with Vydac 218TP C18 columns

The general goal of this work is to investigate the precision of chromatographic data and to determine which properties of chromatographic columns influence this factor. Chromatographic data were acquired under five different sets of experimental conditions for 30 neutral, acidic and basic test compounds on columns packed with Vydac 218TP C18, a polymeric, wide-pore silica-based stationary phase. Five columns packed with samples from the same batch of this packing material were used to measure the column-to-column reproducibility and six columns packed with material from six different batches to measure the batch-to-batch reproducibility. The parameters studied were the retention time, the retention and separation factors, the hydrophobic and the steric selectivities, the column efficiency, and the tailing factor.     

Solvent-induced self-organization approach for polymeric architectures of micropores,hexagons and spheres based on polyurethanes prepared via novel melt transurethane methodology

Solvent-induced self-organization approach was developed, for the first time, to produce polyurethane microporous templates and higher ordered morphologies such as micro or nanometer-sized polymeric hexagons and spheres. A novel melt transurethane methodology was designed and developed for synthesizing new class of cycloaliphatic polyurethanes under nonisocyanate and solvent-free conditions. In this new process, a diurethane monomer was polycondensed with equimolar amounts of diol in presence of Ti(OBu)₄ as catalyst with the removal of low boiling alcohol from the equilibrium. The hydrogen bonding of the polyurethanes are very unique to their chemical structure and they undergo selective phase-separation process in solution to produce hexagonally packed microporous templates. The increase of water content in the polymer solution enhances the phase-separation process and the micro pores coalesce to isolate the encapsulated polymer matrix into polymeric hexagons or densely packed solid spheres. The concentration-dependent solution FTIR and ¹H NMR of the polyurethanes revealed that the polymers possessing higher H-bonding association constants (K) have greater tendency to undergo solvent-induced self-organization phenomena. The mechanism of solvent-evaporation process indicated that only microporous polyurethanes have tendency to form higher ordered hexagons and spheres whereas others failed to show any new morphology. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2351–2366, 2007