荧光磁性表面分子印迹聚合物对柚皮苷的荧光偏振检测

采用荧光磁性表面分子印迹法对柚皮苷进行荧光偏振检测。该方法以二氧化硅包裹的磁性颗粒为基质,甲基丙烯酸和丙烯酰胺为单体,并用异硫氰酸荧光素标记,得到同时具有荧光和磁性的表面分子印迹聚合物。并采用荧光偏振法和紫外分光光度法对制备的聚合物结合能力进行检测。通过与比较2种检测方法可知荧光偏振法更为灵敏,检出限为0.1?mg/L。最后对番茄酱中含有的柚皮苷进行回收率检测,回收率达到81.3%以上。说明采用荧光磁性表面分子印迹法对食品中柚皮苷可快速、高效地检测。     

分子印迹固相萃取-高效液相色谱法检测鸡肉中的四环素类抗生素残留

采用本体聚合法,以盐酸四环素为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,合成了针对四环素类抗生素具有选择性的分子印迹聚合物。并以此材料作为固相吸附剂与高效液相色谱联用,建立了固相萃取-高效液相色谱技术检测鸡肉中的3种四环素类抗生素痕量残留的方法。实验结果表明,该材料具有较强的吸附性和特异识别性。在0.1 mg/L~1.0 mg/L范围内3种四环素类药物的线性关系良好(R20.99),土霉素、四环素、强力霉素的最低检出限分别为0.13μg/L、0.12μg/L、0.14μg/L,5次重复实验的精密度分别为1.27%、1.31%、1.94%。在鸡肉中添加3个浓度(50μg/kg、100μg/kg、200μg/kg)的四环素类抗生素,回收率分别为88.33%~94.95%、80.94%~88.02%、87.69%~93.08%,RSD分别为2.08%~3.63%、1.46%~2.37%、1.04%~3.03%。这项研究的结果表明目前建立的方法可以用于鸡肉中四环素类抗生素的残留检测。     

Determination of Chlorpyrifos in Rice Based on Magnetic Molecularly Imprinted Polymers Coupled with High-Performance Liquid Chromatography

The magnetic molecularly imprinted polymers (MMIPs) were prepared and used for the selective separation of chlorpyrifos from rice samples. The MMIPs were synthesized by surface-imprinted polymerization, using functionalized Fe₃O₄ particles as magnetic cores, chlorpyrifos as template, methacrylic acid as functional monomer, and trimethylolpropane trimethacrylate as cross-linker. Magnetic particles were characterized by scanning electron microscopy, Fourier-transform infrared spectrometry, physical property measurement system, and thermogravimetric analyzer. Adsorption studies were carried out to investigate the specific binding capacity, kinetics, and recognition specificity. The kinetic property of MMIPs was well fitted to the pseudo-second-order equation. The selective recognition experiment demonstrated that MMIPs had high selectivity towards chlorpyrifos over reference compound. Chlorpyrifos extracted from the rice samples was purified with MMIPs and detected by high-performance liquid chromatography. Under the optimal conditions, the detection limit of chlorpyrifos was 0.0072 μg g^?1. The relative standard deviations of intra- and interday ranging from 2.4 to 4.6 % and from 3.5 % to 7.3 % were obtained, respectively. The recoveries of chlorpyrifos at three different fortified concentrations (0.025, 2.5, and 5 μg g^?1) were in the range of 81.2–92.1 %.     

基于分子印迹富集及HPLC-ICP-MS检测海产品中三丁基锡的研究

本文以甲基丙烯酸为功能单体,三丁基锡为模板分子,二甲基丙烯酸乙二醇酯为交联剂,乙腈为致孔剂,采用分子印迹技术并联合高效液相色谱电感耦合等离子质谱(HPLC-ICP-MS)成功地制备了能特异性识别TBT的MIPs。所合成的MIPS经过选择识别、吸附动力学及再生性能等检测,对三丁基锡具有良好的吸附能力和高选择识别能力。并以分子印迹聚合物作为固相萃取吸附剂分离富集TBT,联合高效液相色谱-电感耦合等离子质谱(HPLC-ICP-MS)检测海水及海产品中的三丁基锡。结果表明,用传统分子印迹聚合物作为吸附剂富集分离,在海水、贻贝和大黄鱼样品中检测限(LOD)分别为0.06μg/L、4.0 ng/g和5.0 ng/g,加标回收率分别是61.5%~84.5%、76.2%~93.9%和74.2%~93.3%,线性范围分别是0.1μg/L~30μg/L、5 ng/g~50 ng/g和5 ng/g~500 ng/g。为海产品中有机锡等有机金属的检测提供方法。     

分子印记聚合物压电模拟生物传感器测定烟草中的绿原酸

为快速准确测定烟草中的绿原酸,基于压电石英晶体传感器灵敏的响应性能,结合分子印记聚合物的特异识别性能,研制出绿原酸分子印记压电体声波模拟生物传感器,还探讨了膜的修饰作用,验证了该传感器的印记效应,优化了实验条件。该法线性范围为5.0×10-8～1.0×10-4mol/L,回收率为96.7%～105.0%,RSD为3.7%,并用该法测定了一些烟草中的绿原酸含量。     

磁纳米分子印迹聚合物的制备及性能

以牛血清白蛋白为模板分子,四氧化三铁磁性纳米粒子为载体,多巴胺为功能单体制备磁纳米分子印迹聚合物。用制备的磁纳米分子印迹聚合物吸附蛋白,并测定对蛋白的吸附容量。结果表明：随着吸附时间的增加,吸附量增加,一段时间后可达到吸附饱和;在其他条件不变的情况下,模板浓度增加,吸附容量相应增加;印迹聚合物及其非印迹聚合物对牛血清白蛋白、人血红蛋白和牛血红蛋白的选择性吸附表明所制备的磁性分子印迹聚合物对牛血清白蛋白具有特异性吸附效果。     

肉类食品中磺胺类磁性纳米微粒的制备及其性能研究

Fe3O4磁性纳米粒子作为一种新型多功能材料,因其独特的磁学特性被广泛应用于材料及生物医学等领域。通过共沉淀法制备Fe3O4磁性纳米粒子,聚乙二醇(PEG)进行改性,通过计算机模拟Fe3O4晶体结构,红外光谱对样品进行分析,并进一步进行流变学、磁光性等性能研究。期望可以将磁纳米粒子与分子印迹技术相结合,制备出用于快速检测肉类食品中磺胺残留的新型磁性分子印迹材料。     

磺胺磁性分子印迹聚合物微球的制备及特性研究

Fe3O4磁性微球是近年发展起来并已广泛应用于生物医学等领域的一种新型多功能材料。本文利用分子印迹技术,制备用于快速检测的磺胺分子磁性印迹高分子聚合材料。在磁性粒子表面进行分子印迹合成的磁性分子印迹聚合物核壳微球(MMIPMs),兼具良好的超顺磁性和高选择吸附性两大优点,具有广阔的应用前景。     

水兼容性分子烙印固相萃取-高效液相色谱法测定鸡肉中氟喹诺酮类药物残留

目的：建立分子烙印固相萃取-高效液相色谱测定鸡肉中氟喹诺酮类药物残留的新方法。方法：以甲基丙烯酸为功能单体,恩诺沙星为模板分子,在强极性溶剂甲醇-水体系中制备分子烙印聚合物,考察和评价分子烙印聚合物的特性。鸡肉样品经乙腈提取浓缩后过分子烙印固相萃取柱,乙腈-三氟乙酸(99:1,V/V)洗脱液由高效液相色谱分离和荧光法检测。结果：高亲合力的结合位点的解离常数为Kd1=7.19×10-5 mol/L,最大表观结合位点数Qmax,1=110.19μmol/g;低亲和力结合位点的解离常数为Kd2=2.44×10-3mol/L,最大表观结合位点数Qmax,2 = 965.51μmol/g。氧氟沙星、诺氟沙星、环丙沙星和恩诺沙星等氟喹诺酮类药物的校准曲线在1.0～500 μg/kg范围内呈良好的线性关系(r≥0.9991),检出限(S/N=3)为0.06～0.09μg/kg,平均回收率为75.4%～86.4%(n=3),相对标准偏差小于6%。结论：以水兼容性分子烙印固相萃取-高效液相色谱法可实现氟喹诺酮药物的有效分离和灵敏测定。     

磁性分子印迹聚合物提取-超高效液相色谱-串联质谱法测定乳及乳制品中的4 种伪蛋白

建立磁性分子印迹聚合物（magnetic molecular imprinted polymers,MMIPs）提取结合超高效液相色谱-串联质谱法测定乳及乳制品中4?种伪蛋白（三聚氰胺、环丙氨嗪、双氰胺和缩二脲）的方法。以缩二脲-13C2和环丙氨嗪-D4为印记分子,Fe3O4为磁性组分,制备具有特异识别性的MMIPs提取样品中的目标化合物,超高效液相色谱-串联质谱法检测。结果表明,4?种化合物在5～200?ng/mL范围内具有良好的线性关系,线性相关系数大于0.999。三聚氰胺、环丙氨嗪、双氰胺和缩二脲在牛奶样品中的检出限分别为0.10、0.02、0.05、0.50?μg/kg,在奶粉样品中的检出限分别为0.25、0.05、0.13、1.25?μg/kg。回收率为80.5%～96.1%,相对标准偏差为1.1%～9.2%。利用本方法对实际样品中4?种化合物进行测定,分析结果显示该方法所得到的数值准确、可靠。     

高效液相紫外法检测肉鸡组织中的阿奇霉素残留

目的：研究建立反相液相色谱法监控肉鸡组织阿奇霉素的残留。方法：采用C18 柱(4.6mm × 250mm,5μm),乙腈- 异丙醇-0.002mol/L 磷酸氢二钠(60:15:25,V/V)为流动相,紫外检测波长210nm,样品用氯仿- 异丙醇(95:5,V/V)提取,氮气流吹干,加流动相溶解后进样。结果：阿奇霉素在0.05～5.0μg/g 范围内与峰面积呈线性相关,r ＞ 0.990;血清中最低检测限为0.02μg/ml,组织最低定量限为0.05μg/g,血清回收率＞ 83%,组织回收率＞ 77%,RSD ＜ 5%。结论：该方法快速、精确、重复性好,符合肉鸡组织中阿奇霉素残留检测的要求。     

Thin-layer Chromatographic Method for Quantification of Sulfonamides in Chicken Meat

The sulfonamides are a widely used group of antimicrobials in veterinary practice especially in developing countries due to their broad spectrum of activity, availability, and low cost. The objective of this study was to establish a thin-layer chromatographic (TLC) method to detect residues of commonly used sulfonamides in Sri Lanka in chicken. The TLC method separated sulfadiazine (SDZ), sulfadoxine (SD), sulfamethazine (SMZ), sulfathiazole (STZ), and sulfaquinoxaline (SQ) on silica gel plates using chloroform: n_butanol (90:10). Sulfonamides densitometric measurements were conducted by derivatising with fluorescamine and scanning the separated bands at 366 nm. The quantity of the sulfonamide in samples was calculated using a standard calibration curve obtained by plotting values of peak area against sulfonamide concentrations at 200, 150, 100, 50, 30, and 25 ng/g. The mean percentage recoveries were 80–120% while the intra-day and inter-day precision was 3–22% and 6–42% respectively. The SD had the highest limit of detection (LOD) and limit of quantification (LOQ) values of 60 and 100 ng/g respectively. The LOD of all the other analytes were 40 ng/g, and STZ had the lowest LOQ values of 50 ng/g. A reliable, inexpensive, simple, liquid-liquid extraction method for the rapid analysis of five sulfonamides at maximum residue limit (MRL) in chicken using TLC was developed.     

磁性分子印迹纳米粒子对四环素的富集分离

以羧基化的Fe_3O_4纳米粒子为载体,四环素为模板分子,采用表面印迹技术制备对四环素具有特异性识别的磁性分子印迹纳米粒子。分别优化磁性分子印迹纳米粒子的制备条件和富集分离四环素的条件,为食品中四环素残留的富集分离及后续检测,提供一种简便快速的方法。结果表明,当模板分子和功能单体的摩尔比为1∶8(总体积为110 mL),羧基化Fe_3O_4纳米粒子的添加量为0.5 g,洗脱液甲醇-乙酸溶液的体积比为8∶2时,所制备的磁性分子印迹纳米粒子吸附性能最佳。应用最优条件制备的磁性分子印迹纳米粒子10 mg,对2 mL 0.08 mg/mL的四环素进行吸附,当反应时间为40 min时,其吸附效率可达94.10%。     

联苯三唑醇分子印迹聚合物的合成及吸附性能研究

制备联苯三唑醇分子印迹聚合物(BMIP)并研究其特异识别能力。以联苯三唑醇为模板分子,α-甲基丙烯酸(MAA)为功能单体,采用本体聚合法合成分子印迹聚合物(MIP)。考察不同致孔剂对模板物质与功能单体相互作用力的影响,以及采用不同比例模板分子与功能单体合成的聚合物对联苯三唑醇的吸附量的影响,通过静态吸附实验研究吸附性能,并进行Scatchard分析。结果表明乙腈和四氢呋喃为致孔剂时,联苯三唑醇的最大吸收波长均发生红移,分别红移了5 nm和6 nm,且吸收峰均增强。由Scatchard分析可知,联苯三唑醇与MAA形成了两类结合位点,其解离常数KD1=3.16 mmol/L、KD2=107.53 mmol/L。四氢呋喃和乙腈更适合用于联苯三唑醇分子印迹聚合物的制备。合成的印迹聚合物对模板分子具有很强的亲和力和良好的识别能力,可以用做联苯三唑醇的分离材料。     

香草醛分子印迹聚合物微球的合成及表征

香草醛作为食品中一种重要的调味剂,可以从热带兰花香荚兰的种子中找到。本文以香草醛(VAN)为模板分子,a-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,二甲基亚砜(DMSO)为溶剂,分别采用沉淀聚合法、悬浮聚合法、本体聚合法制备了香草醛分子印迹聚合物(微球)(MIPs)。通过紫外光谱(UV)、傅里叶变换红外光谱仪(FT-IR)研究了模板分子与功能单体之间的相互作用和最佳配比,利用透射电子显微镜考察了分子印迹聚合物的微观形貌。采用平衡和等温吸附实验对印迹聚合物的吸附性能进行了研究。实验表明,MAA与VAN之间通过氢键相互作用,沉淀聚合法制备的MIPs具有均匀规则的球状结构,且表现出对VAN更好的结合能力,具有较高的特异识别性。     

A Novel Molecularly Imprinted Polymer Based on Carbon Nanotubes for Selective Determination of Dioctyl Phthalate from Beverage Samples Coupled with GC/MS

Phthalates represent a potential risk for humans, since they are ubiquitous environmental contaminants. Efficient extraction and purification procedures are demanded for the detection of low concentration levels of phthalates. In this work, a novel type of molecularly imprinted polymers coated onto the surface of vinyl functionalized multi-walled carbon nanotubes was synthesized and coupled with gas chromatography–mass spectrometry (GC/MS) for the selective separation and determination of dioctyl phthalate (DOP) in beverage samples. The morphology, structure property, and thermostability of the resultant polymers were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The adsorption properties of the prepared polymers were investigated by equilibrium rebinding and competitive experiments. The resultant imprinted nanomaterials exhibited high capacity and favorable selectivity. In addition, the feasibility of the developed method using the obtained imprinted polymers as a solid-phase sorbent coupled with GC/MS for the selective isolation and determination of DOP in different beverage samples was demonstrated. Under optimal conditions, the limit of detection of the proposed method for DOP was 2.3 ng L^?1. DOP spiked at three levels of concentration in beverage samples was extracted and determined through the application of the present method, with recoveries ranging from 88.6 to 93.0 % with relative standard deviations less than 5.6 %.     

香兰素分子印迹微球的制备及识别机理

以香兰素(Van)为模板、甲基丙烯酸(MAA)为功能单体、偶氮二异丁腈(AIBN)为引发剂和乙烯二醇二甲基丙烯酸酯(EDMA)为交联剂,采用沉淀聚合法合成一种新型的对Van有特异识别功能的分子印迹聚合物微球(MIPs)。通过UV、傅里叶变换红外光谱仪(FT-IR)和1H NMR光谱法研究模板与功能单体之间的相互作用和识别机理,采用扫描电镜(SEM)考察MIPs表面形态,通过平衡和等温吸附实验对MIPs和非分子印迹微球(NIPs)吸附性能进行研究。结果表明:MAA与Van之间通过氢键相互作用,MIPs具有表面光滑的规则球状结构,MIPs对Van的吸附和识别能力远高于NIPs,并且在120min后达到吸附平衡状态,Scatchard分析表明在MIPs上形成了均匀的对Van有特异性的结合位点,最大表观吸附量Qmax和平衡离解常数Kd分别为7.357μmol/g和4.243×10-5mol/L;选择性分离、分子印迹固相萃取(MIP-SPE)和HPLC实验分析表明,MIPs对Van具有很好的分离和富集能力。     

Study on a Molecularly Imprinted Solid-Phase Extraction Coupled to Capillary Electrophoresis Method for the Determination of Trace Trichlorfon in Vegetables

How to determine the pesticide residues in vegetable is an urgent problem. In this study, we reported a new method of solid-phase extraction coupled to capillary electrophoresis (SPE–CE) based on a molecularly imprinted polymer (MIP) for determination of trace trichlorfon. The electrophoretic conditions and factors which affected the molecularly imprinted solid-phase extraction were optimized. Under optimal conditions, the linear ranges of the calibration graph were 0.1 μg/L to 10 mg/L. The limit of detection (LOD) and method quantitation limit (MQL) were 4.9 and 16.2 μg/kg, respectively. With a flow rate of 2.5 mL/min for 50 mL loading, an enrichment factor of 160 was obtained. The relative standard deviation (RSD) for five replicate extractions of 0.01 mg/L trichlorfon standard solution was 4.5 %. The blank cucumber, lettuce, and radish samples spiked with trichlorfon at three levels were extracted and determined by this presented method with recoveries ranging from 77.6 to 93.2 %. Moreover, this proposed methodology was successfully applied to the quantitative detection of the trichlorfon residues in the leek samples, and the results were in good agreement with that obtained by the gas chromatography method.     

多环芳烃分子印迹柱-高效液相色谱荧光检测法快速测定烤肉中15 种多环芳烃

建立一种高效液相色谱-荧光检测（high performance liquid chromatography-fluorescence detection,HPLC-FLD）法同时测定烤肉中15 种多环芳烃（polycyclic aromatic hydrocarbons,PAHs）的方法。样品经超声提取,多环芳烃分子印迹柱（molecular imprinting column of PAHs,MIP-PAHs）净化,通过HPLC分离,外标法定量。结果表明：15 种PAHs在质量浓度1～50 ng/mL范围内与色谱峰面积呈良好的线性关系,r＞0.999 5;在5.0、10.0、25.0 μg/kg 3 个加标水平下,平均回收率为71.1%～98.8%,相对标准偏差为1.0%～5.8%;方法检出限（RS/N=3）为0.33～3.30 μg/kg,定量限（RS/N=10）为1.0～10.0 μg/kg。