儿茶素活性成分分子印迹聚合物的分子识别特性及固相萃取研究

以表没食子儿茶素没食子酸酯(EGCG)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，合成EGCG分子印迹聚合物。利用该聚合物对EGCG及其异构体和结构类似物进行分子识别特性研究。结果表明：分子印迹聚合物对模板分子具有较高的选择性和识别能力，而空白聚合物却不具备这样的特性。在此基础上，把聚合物用于固相萃取茶叶提取物茶多酚，分离富集其中的儿茶素活性成分单体EGCG，获得了满意的效果。     

分子印迹聚合物固相萃取研究进展

对最新报道的分子印迹聚合物作为固相萃取剂及其在色谱样品前处理方面的应用进行综述和展望,主要包括固相萃取、基质固相分散萃取、固相微萃取、搅拌棒吸附萃取和磁性材料萃取,同时总结了分子印迹聚合物制备技术面临的挑战和问题,提出了可能的解决方案。     

扑热息痛分子印迹聚合物应用于固相萃取的研究

以扑热息痛为印迹分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂合成了棒状的印迹聚合物;把其装于自制的固相萃取柱中,研究了以乙腈和水为溶剂时扑热息痛在柱上的保留行为;通过优化清洗、洗脱条件,使扑热息痛和与其具有相似结构的非那西丁、对叔丁基苯酚在柱上得到了很好的分离;同时也测定了治疗感冒的药物海王银得菲中扑热息痛的含量,其回收率可达94．3％．     

槲皮素分子印迹聚合物的制备及固相萃取性能研究

采用分子印迹技术, 以槲皮素为模板分子, 丙烯酰胺为功能单体, 乙二醇二甲基丙烯酸脂为交联剂, 通过热引发聚合, 制备了槲皮素分子印迹聚合物, 并通过装入固相萃取柱试验了聚合物对槲皮素的选择性能. 结果表明, 该分子印迹聚合物对槲皮素具有高度选择性, 为从天然产物中高效分离富集黄酮活性成分槲皮素提供了一种新材料.     

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%。     

赛庚啶-分子印迹聚合物的制备及其固相萃取研究

以赛庚啶为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,通过优化致孔剂、单体及模板与单体摩尔比等因素,合成了对赛庚啶具有高选择性的分子印迹聚合物,其表面积达24.9 m2/g。制备的印迹聚合物固相萃取小柱(MISPE)依次以甲醇和水活化小柱,水溶液上样,水和甲醇依次洗涤,氨化甲醇(5∶95,V/V)洗脱,赛庚啶在制备MISPE小柱上的回收率为94.0%,而非分子印迹小柱(NISPE)的回收率仅为38.9%;MISPE结合赛庚啶的容量达8.8 mg/g,印迹因子约为2.32。在优化的固相萃取条件下,10 mg/L赛庚啶、阿米替林、磺胺嘧啶和甲氧苄啶混合标准溶液上样,进行选择性实验。以0.05%戊烷磺酸钠溶液和乙腈为流动相,梯度洗脱,在MISPE小柱上,与CYP化学结构差异较大的磺胺嘧啶和甲氧苄啶回收率均小于10%,结构相似的阿米替林回收率达70%,赛庚啶回收率大于90%;4种分析物在NISPE小柱上的回收率均小于30%。制备的MISPE小柱应用于畜禽饮用水样中赛庚啶的分离富集和分析测定,方法回收率为80.5%~97.7%,检出限达0.01 mg/L。     

非那西汀印迹聚合物固相萃取性能研究

研究非那西汀分子印迹聚合物的固相萃取性能。用本体聚合法制备非那西汀分子印迹聚合物,通过静态平衡吸附试验及固相萃取试验,研究其固相萃取性能。非那西汀模板聚合物的吸附能力明显强于空白聚合物。模板聚合物对浓度为0.03mmol/L的非那西汀标准溶液一次性萃取率为74.2%。非那西汀印迹聚合物对非那西汀具有特异性识别性能,可作为固相萃取固定相的应用研究。     

吡虫啉分子印迹聚合物的合成及固相萃取性能研究

采用分子印迹技术,以丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在甲醇溶液中合成了吡虫啉分子印迹聚合物,研究了聚合物的吸附性和选择性,用聚合物固相萃取大蒜中吡虫啉残留量。结果表明,聚合物通过离子键和氢键对模板分子产生了印迹效应,对吡虫啉具有明显的选择性。通过优化淋洗和洗脱条件,对大蒜中的残留吡虫啉富集。     

马拉硫磷分子印迹聚合物的制备及其在固相萃取中的应用

以马拉硫磷为模板分子,采用原位逐步聚合法制备了具有良好识别性能的分子印迹聚合物(MIPs),考察了马拉硫磷、甲基对硫磷、对硫磷及甲胺磷在马拉硫磷聚合物的选择性分离富集特性。用聚合物固相萃取了蜂蜜、蔬菜和天然水中的马拉硫磷。结果表明,聚合物对模板分子产生了印迹效应,对马拉硫磷有明显的选择性。流速为1.0 mL/min,进...     

甲醛分子印迹聚合物的制备、性能及水产品测定

以甲醛为模板分子,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,用氯仿做溶剂,制备了甲醛分子印迹聚合物,并优化了此制备方法,在模板分子、功能单体和交联剂的摩尔比为1:2:20,预聚合时间为4 h,聚合时间为8 h的条件下制备的聚合物对甲醛的特异性吸附能力最好,当甲醛溶液的浓度为2 mmol/L时聚合物对甲醛的吸附量达到了12.40×10^-2 mmol/g。 对市售鱿鱼处理后用高效液相色谱法测定得样品中甲醛的浓度是5.92 mg/Kg,将该样稀释100倍以后甲醛已无法检出,经MIP柱富集后检测计算样品中甲醛浓度为5.76 mg/Kg,表明该聚合物用于样品前处理高效且结果无显著性差异。     

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.     

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...     

Synthesis and application of a molecularly imprinted polymer in the solid-phase extraction of ketoprofen from wastewater

Ketoprofen is a nonsteroidal anti-inflammatory drug widely consumed by humans as it possesses analgesic activities. A selective molecularly imprinted polymer (MIP) for ketoprofen was synthesized and applied as a solid-phase extraction sorbent. MIP was synthesized using 2-vinylpyridine, ethylene glycol dimethacrylate, 1,1′-azobis(cyclohexanecarbonitrile), toluene/acetonitrile (9:1, v/v), and ketoprofen as a functional monomer, cross-linker, initiator, porogenic mixture, and template, respectively. The polymerization was performed at 60 °C for 16 h, and thereafter the temperature was increased to 80 °C for 24 h to achieve a solid monolith polymer. Nonimprinted polymer was synthesized in a similar manner with the omission of ketoprofen. Characterization with thermogravimetric analysis and X-ray diffraction showed that the synthesized polymers were thermally stable and amorphous. Solid-phase extraction cartridges packed with MIP were used with high-performance liquid chromatography for quantitative analysis of ketoprofen in wastewater. The analytical method gave detection limits of 0.23, 0.17, and 0.09 μg/L in wastewater influent, effluent, and deionized water, respectively. The recovery for the wastewater influent and effluent spiked with 5 μg/L of ketoprofen was 68%, whereas 114% was obtained for deionized water. The concentrations of ketoprofen in the influent and effluent samples were in the ranges of 22.5–34.0 and 1.14–5.33 μg/L, respectively. Overall, the analytical method for the analysis of ketoprofen in wastewater was rapid, affordable, accurate, precise, sensitive, and selective.     

Selective solid-phase extraction of amoxicillin and cephalexin from urine samples using a molecularly imprinted polymer

In this paper we describe, for the first time, a molecularly imprinted polymer (MIP) for the antibiotic amoxicillin (AMX), synthesised by a noncovalent molecular imprinting approach and used to extract AMX selectively from urine samples. The MIP was applied as a molecularly selective sorbent in molecularly imprinted SPE (MISPE) in an off-line mode, where it showed useful cross-selectivity for a structurally related antibiotic, cephalexin (CPX). By using a MISPE protocol, the MIP was able to selectively extract both AMX and CFX from 5 mL of water spiked with 10 mg/L with recoveries of 75 and 78% for AMX and CFX, respectively. When applied to real samples (urine) at clinically relevant concentrations, recoveries from 2 mL of human urine spiked with 20 mg/L decreased slightly to 65 and 63% for AMX and CFX, respectively. To demonstrate further the selectivity of the MIP obtained, a comparison with commercially available SPE cartridges was performed. Improvements in the retention of both AMX and CFX on the MIP were obtained relative to the commercially available cartridges, and the MISPE extracts were considerably cleaner, due to molecularly selective analyte binding by the MIP.     

A new molecularly imprinted polymer for selective extraction of cotinine from urine samples by solid-phase extraction

Cotinine, the main metabolite of nicotine in human body, is widely used as a biomarker for assessment of direct or passive exposure to tobacco smoke. A method for molecularly imprinted solid-phase extraction (MISPE) of cotinine from human urine has been investigated. The molecularly imprinted polymer (MIP) with good selectivity and affinity for cotinine was synthesized using cotinine as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. The imprinted polymer was evaluated for use as a SPE sorbent, in tests with aqueous standards, by comparing recovery data obtained using the imprinted form of the polymer and a non-imprinted form (NIP). Extraction from the aqueous solutions resulted in more than 80% recovery. A range of linearity for cotinine between 0.05 and 5 μg mL⁻¹ was obtained by loading 1 mL blank urine samples spiked with cotinine at different concentrations in acetate buffer of pH 9.0, and by using double basic washing and acidic elution. The intra-day coefficient of variation (CV) was below 7% and inter-day CV was below 10%. This investigation has provided a reliable MISPE–HPLC method for determination of cotinine in human urine from both active smokers and passive smokers. Figure     

Multivariate optimization of molecularly imprinted polymer solid-phase extraction applied to parathion determination in different water samples

In this work a parathion selective molecularly imprinted polymer was synthesized and applied as a high selective adsorber material for parathion extraction and determination in aqueous samples. The method was based on the sorption of parathion in the MIP according to simple batch procedure, followed by desorption by using methanol and measurement with square wave voltammetry. Plackett-Burman and Box-Behnken designs were used for optimizing the solid-phase extraction, in order to enhance the recovery percent and improve the pre-concentration factor. By using the screening design, the effect of six various factors on the extraction recovery was investigated. These factors were: pH, stirring rate (rpm), sample volume (V₁), eluent volume (V₂), organic solvent content of the sample (org%) and extraction time (t). The response surface design was carried out considering three main factors of (V₂), (V₁) and (org%) which were found to be main effects. The mathematical model for the recovery percent was obtained as a function of the mentioned main effects. Finally the main effects were adjusted according to the defined desirability function. It was found that the recovery percents more than 95% could be easily obtained by using the optimized method. By using the experimental conditions, obtained in the optimization step, the method allowed parathion selective determination in the linear dynamic range of 0.20-467.4 μg L⁻¹, with detection limit of 49.0 ng L⁻¹ and R.S.D. of 5.7% (n = 5). Parathion content of water samples were successfully analyzed when evaluating potentialities of the developed procedure.     

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.     

Selective enrichment of anti-inflammatory drugs from river water samples by solid-phase extraction with a molecularly imprinted polymer

A molecularly imprinted polymer (MIP) is synthesised by a noncovalent protocol in which ibuprofen was used as a template molecule. The polymer was evaluated chromatographically and it was seen that the MIP showed cross-reactivity. Subsequently, when this polymer was used as sorbent in SPE it was possible to selectively extract a mixture of nonsteroidal anti-inflammatory drugs from aqueous samples when a cleanup step with dichloromethane was performed. The performance of the MIP was evaluated with river water and water from a wastewater treatment plant, and compared with the performance of a commercial Isolute ENV+ sorbent.     

选择性提取单取代磺酰脲除草剂的印迹聚合物的合成及评价

以丙烯酰胺为功能单体合成了新型的单嘧磺隆印迹聚合物,用平衡吸附及液相色谱的方法研究了印迹聚合物对于印迹分子及其结构类似化合物NK#94827的识别特性及亲和能力.研究结果表明,以丙烯酰胺为功能单体得到的印迹聚合物对NK#94827具有较强的识别能力;为印迹聚合物应用于环境样品中NK#94827及其结构类似化合物的分析打下了基础.