三聚氰胺分子印迹聚合物的制备及奶制品中三聚氰胺的分离

采用分子印迹技术,以三聚氰胺为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了对三聚氰胺具有较好选择性的分子印迹聚合物.通过静态平衡结合实验研究了该聚合物的结合能力和选择性能,与化学组成相同的相应非印迹聚合物相比,三聚氰胺的分子印迹聚合物对三聚氰胺有较高的吸附性能和选择性.以该分子印迹聚合物为固相萃取材料填充固相萃取小柱,可以从奶粉、纯牛奶等奶制品中选择性地分离、富集三聚氰胺,并有效地去除奶制品中的复杂基质,取得了良好的效果.对奶粉和液态奶提取液的加标回收率分别为91% ～103%、93% ～98%,相对标准偏差(n=3)分别为7.9%和1.1%.该分子印迹聚合物还有望用于其它奶制品的分析.     

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。     

分子印迹聚合物在复杂体系分离中的应用研究进展

分子印迹聚合物的高选择性使其在复杂体系样品的净化富集中具有很强的应用潜力通过文献综述了分子印迹聚合物在固相提取中的应用．介绍了目前各种印迹聚合物制备方法,提出了在样品净化富集中选择淋洗条件需要考虑的问题及分子印迹聚合物在复杂体系分离中应用的发展前景。     

己烯雌酚印迹分子聚合物合成及其在残留分析中的应用

以己烯雌酚（Diethylstilbestrol,DES）为模板分子,α-甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,合成己烯雌酚分子印迹聚合物;以该聚合物为填料制成固相萃取小柱,应用于己烯雌酚残留分析的样品前处理,并比较了该固相萃取小柱与C18固相萃取小柱对DES保留行为的差异。通过选择不同浓度的甲醇水溶液,己烯雌酚达到理想的分离纯化效果;对加标鸡肉样进行了含量测定,回收率可达95％以上。     

吡哌酸分子印迹聚合物的分子识别

采用分子印迹技术合成了吡哌酸分子印迹聚合物。运用平衡结合实验研究了聚合物的吸附特性和选择性识别能力。Scatchard分析表明,在本文所研究的浓度范围内,聚合物中形成了两类不同的结合位点。吡哌酸分子印迹聚合物对吡哌酸呈现较高的选择识别特性,可作为固相萃取剂,在人血清吡哌酸的分析中对样品进行了有效的提取和净化。     

分子印迹基质固相分散-液相色谱法测定牛奶中的氯霉素残留

以对模板分子具有较强识别特性的分子印迹聚合物为基质固相分散吸附剂, 提取牛奶中痕量氯霉素, 最后用HPLC法测定. 研究了氯霉素分子印迹聚合物对样品中氯霉素的提取和净化效果, 在优化条件下, 方法的检出限为0.15 ng/mL, 定量限为0.50 ng/mL. 不同氯霉素添加量的回收率大于93.2%, RSD＜5.9%. 方法适用于牛奶中氯霉素残留的测定.     

应用介孔分子印迹聚合物萃取粮食中的乙酰甲胺磷

以乙酰甲胺磷为模板分子,3-氨基丙基三乙氧基硅烷(APTES)为功能单体,表面活性剂正十二烷胺(DDA)为介孔模板剂,正硅酸乙酯为交联剂,采用溶胶凝胶技术制备乙酰甲胺磷介孔分子印迹聚合物(MIP),并对其进行了表征。Scatchard分析表明,该聚合物对乙酰甲胺磷有两种结合方式,最大表观结合量Q_(max1)=47.03 mg/g,Q_(max2)=90.31 mg/g;平衡解离常数k_(d1)=57.14 mg/L,k_(d2)=188.68 mg/L。吸附动力学测定结果显示,其对乙酰甲胺磷的吸附符合准二级动力学模型;吸附热力学测定结果显示其吸附为放热过程。将该聚合物用于基质固相分散萃取(MSPD)粮食中乙酰甲胺磷,最佳条件为:聚合物与样品的质量比为1∶1,研磨时间为8 min,淋洗剂为乙醇-水(2∶1,体积比),洗脱剂为乙腈-乙酸溶液(19∶1,体积比)。所得洗脱液采用高效液相色谱法检测,测得乙酰甲胺磷的线性范围为0.03～0.3μg/g,检出限为0.015μg/g,回收率为92.5%～97.1%,相对标准偏差为2.9%～3.7%。该方法兼具介孔分子印迹技术的高选择性如和MSPD技术的快速分离性,为乙酰甲胺磷残留分析提供了新思路。     

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。     

水溶液悬浮聚合法制备妥拉苏林分子印迹聚合物微球及其性能研究

以药物妥拉苏林为印迹分子,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,采用水溶液悬浮聚合方法,制得对妥拉苏林有较好选择识别能力的球形分子印迹聚合物（molecularly imprinted polymer,MIP）。扫描电子显微镜（SEM）照片显示MIP微球粒径为50～200μm,静态平衡吸附实验表明,MIP对妥拉苏林的吸附量是95.28μmol/L,而空白分子印迹聚合物（non-imprinted polymer,NIP）的吸附量是52.66μmol/L,氮气吸附法测得MIP和NIP的比表面积分别为27.17 m^2/g和10.27 m^2/g。将所得的MIP应用于固相萃取（SPE）的固定相,结果表明,该MIP能选择性吸附妥拉苏林,当以结构类似的药物萘甲唑啉为竞争底物时,分离因子可达1.75。MIP用于人尿样的分离和富集时,回收率为99%～114%,相对标准偏差为1.5%～2.5%。     

Recent Advances in Molecularly Imprinted Polymers for Antibiotic Analysis

The abuse and residues of antibiotics have a great impact on the environment and organisms, and their determination has become very important. Due to their low contents, varieties and complex matrices, effective recognition, separation and enrichment are usually required prior to determination. Molecularly imprinted polymers (MIPs), a kind of highly selective polymer prepared via molecular imprinting technology (MIT), are used widely in the analytical detection of antibiotics, as adsorbents of solid-phase extraction (SPE) and as recognition elements of sensors. Herein, recent advances in MIPs for antibiotic residue analysis are reviewed. Firstly, several new preparation techniques of MIPs for detecting antibiotics are briefly introduced, including surface imprinting, nanoimprinting, living/controlled radical polymerization, and multi-template imprinting, multi-functional monomer imprinting and dummy template imprinting. Secondly, several SPE modes based on MIPs are summarized, namely packed SPE, magnetic SPE, dispersive SPE, matrix solid-phase dispersive extraction, solid-phase microextraction, stir-bar sorptive extraction and pipette-tip SPE. Thirdly, the basic principles of MIP-based sensors and three sensing modes, including electrochemical sensing, optical sensing and mass sensing, are also outlined. Fourthly, the research progress on molecularly imprinted SPEs (MISPEs) and MIP-based electrochemical/optical/mass sensors for the detection of various antibiotic residues in environmental and food samples since 2018 are comprehensively reviewed, including sulfonamides, quinolones, β-lactams and so on. Finally, the preparation and application prospects of MIPs for detecting antibiotics are outlined.     

Extraction of matrine from soil with matrix solid‐phase dispersion by molecularly imprinted polymers derived from lignin‐based Pickering emulsions

Molecularly imprinted polymers prepared by Pickering emulsion method with lignin as stable particle were used as dispersants in matrix solid‐phase dispersion, followed by ultra high performance liquid chromatography with tandem mass spectrometry to research the degradation behavior of matrine in soil. The molecularly imprinted polymers have regular morphology and uniform particles. Moreover, the adsorption experiments and the conditions of matrix solid‐phase dispersion were discussed. With the optimal conditions of matrix solid‐phase dispersion, the recoveries of matrine were 95.4–98.2%, relative standard deviations were 0.6–5.1%, and the detection limit was 5 ng/g. Moreover, the degradation behavior of matrine in soil was researched, it indicated the half‐life of matrine was 2.7–3.2 days, and it was an environmentally friendly botanical pesticide. The method was successfully applied to separate and analyze matrine in soil samples can decrease analysis time, save organic solvents, and improve the selectivity.     

Magnetic Molecularly Imprinted Polymer Preconcentration of 4-Chlorophenol with Determination by High-Performance Liquid Chromatography

A novel magnetic dummy molecularly imprinted polymer based on multiwalled carbon nanotubes was prepared with 2-amino-4-chlorophenol as the dummy template for rapid separation and enrichment of 4-chlorophenol in aqueous samples. The magnetic dummy molecularly imprinted polymer was characterized by infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and vibrating sample magnetometry. The saturation adsorption capacity of the magnetic dummy molecularly imprinted polymer toward 4-chlorophenol was up to 54.3?mg?g^?1 at 298?K, which is higher than for previously reported imprinted polymers. The magnetic dummy molecularly imprinted polymers were coupled with high-performance liquid chromatography to isolate and determine 4-chlorophenol in fish bile and river water with the recoveries from 95.8 to 98.9% and 96.6 to 99.1%, respectively.     

加替沙星印迹聚合物微球的合成及特异吸附性能

采用沉淀聚合法制备了加替沙星分子印迹聚合物(MIP)微球, 对其形貌和结构进行表征, 并对聚合反应条件进行优化|采用静态吸附试验研究聚合物对模板分子及其结构类似物的吸附行为和选择性识别特性. 结果表明, 在最佳实验条件下, 40 min印迹聚合物即可达到对底物的吸附平衡|在印迹聚合物中存在两类结合位点, 特异性和非特异性结合位点的最大吸附量分别为363和458 μmol/g|与化学组成相同的非印迹聚合物(NIP)相比, MIP对结构相似的喹诺酮类抗生素具有良好的选择吸附性能|该法制备的MIP微球易于再生, 放置3个月以后, 仍能够对喹诺酮类抗生素进行有效识别.     

以分子印迹聚合物为固定相分离和测定氟喹诺酮类药物

以氧氟沙星作为模板分子合成了分子印迹聚合物,并通过高效液相色谱法研究了印迹聚合物的识别特性。实验结果表明,印迹聚合物对模板分子具有很强的亲和力和特定的选择性。作为色谱固定相,氧氟沙星印迹聚合物和目标分子之间的相互作用除了印迹部分的离子和氢键作用外,也存在非印迹部分的疏水作用。同时研究了色谱条件对氟喹诺酮类药物分离的影响。     

Magnetic Molecularly Imprinted Polymers for the Rapid and Selective Extraction and Detection of Methotrexatein Serum by HPLC-UV Analysis

In this work, novel selective recognition materials, namely magnetic molecularly imprinted polymers (MMIPs), were prepared. The recognition materials were used as pretreatment materials for magnetic molecularly imprinted solid-phase extraction (MSPE) to achieve the efficient adsorption, selective recognition, and rapid magnetic separation of methotrexate (MTX) in the patients’ plasma. This method was combined with high-performance liquid chromatography–ultraviolet detection (HPLC–UV) to achieve accurate and rapid detection of the plasma MTX concentration, providing a new method for the clinical detection and monitoring of the MTX concentration. The MMIPs for the selective adsorption of MTX were prepared by the sol–gel method. The materials were characterized by transmission electron microscopy, Fourier transform-infrared spectrometry, X-ray diffractometry, and X-ray photoelectron spectrometry. The MTX adsorption properties of the MMIPs were evaluated using static, dynamic, and selective adsorption experiments. On this basis, the extraction conditions were optimized systematically. The adsorption capacity of MMIPs for MTX was 39.56 mgg⁻¹, the imprinting factor was 9.40, and the adsorption equilibrium time was 60 min. The optimal extraction conditions were as follows: the amount of MMIP was 100 mg, the loading time was 120 min, the leachate was 8:2 (v/v) water–methanol, the eluent was 4:1 (v/v) methanol–acetic acid, and the elution time was 60 min. MTX was linear in the range of 0.00005–0.25 mg mL⁻¹, and the detection limit was 12.51 ng mL⁻¹. The accuracy of the MSPE–HPLC–UV method for MTX detection was excellent, and the result was consistent with that of a drug concentration analyzer.     

亲水性分子印迹聚合物的制备及其在天麻素分析检测中的应用

以天麻素为模板分子,α-1-烯丙基-2-N-乙酰胺基葡萄糖为新型亲水性功能单体,N,N'-亚甲基双丙烯酰胺为交联剂,合成了对天麻素有高选择性的亲水性分子印迹聚合物(MIPs)。吸附结果表明,MIPs能够特异性识别天麻素。对MIPs吸附剂性能的考察证明,亲水性天麻素MIPs可作为固相萃取(SPE)吸附剂分离纯化天麻素。方法验证实验显示了良好的回收率(90.4%~97.1%)和精密度(3.3%~5.2%,n=5)。该文以新型亲水性功能单体为基础,建立了天麻素的分子印迹固相萃取样品前处理方法。     

Voltammetric Determination of Valaciclovir Using a Molecularly Imprinted Polymer Modified Carbon Paste Electrode

A molecularly imprinted polymer (MIP) was rationally synthesized with the aid of computer based studies. The computational studies were used to screen for the most suitable template to functional monomer molar ratio. Two functional monomers were involved in the study (methacrylic acid and 4‐vinylpyridine). Four MIP ratios were synthesized in accordance with the results of the computational studies and their performance was evaluated using equilibrium rebinding assays. The MIP with the best performance was used as an additive in carbon paste electrodes for the voltammetric determination of valaciclovir (VCV). Following the optimization of voltammetric parameters, a linear response was obtained in the range of 1.0x10⁻⁶–7.0x10⁻⁴ M with a limit of detection at 4.45x10⁻⁷ M. The MIP modified carbon paste electrode was successfully applied for the determination of VCV in pure solutions and dosage form.     

The Ultratrace Determination of Fluoroquinolones in River Water Samples by an Online Solid-Phase Extraction Method Using a Molecularly Imprinted Polymer as a Selective Sorbent

Fluoroquinolones (FQs) are broad-spectrum antibiotics widely used to treat animal and human infections. The use of FQs in these activities has increased the presence of antibiotics in wastewater and food, triggering antimicrobial resistance, which has severe consequences for human health. The detection of antibiotics residues in water and food samples has attracted much attention. Herein, we report the development of a highly sensitive online solid-phase extraction methodology based on a selective molecularly imprinted polymer (MIP) and fluorescent detection (HPLC-FLD) for the determination of FQs in water at low ng L⁻¹ level concentration. Under the optimal conditions, good linearity was obtained ranging from 0.7 to 666 ng L⁻¹ for 7 FQs, achieving limits of detection (LOD) in the low ng L⁻¹ level and excellent precision. Recoveries ranged between 54 and 118% (RSD < 17%) for all the FQs tested. The method was applied to determining FQs in river water. These results demonstrated that the developed method is highly sensitive and selective.