Detection of amoxicillin residues in egg extract with a molecularly imprinted polymer on gold microchip using surface plasmon resonance and quartz crystal microbalance methods

In this study, surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) sensors were prepared for the detection of amoxicillin from the commercial and local chicken eggs by using molecular imprinting technique. Amoxicillin imprinted poly(hydroxyethyl methacrylate-methacrylic acid) polymeric film was synthesized onto the surface of the SPR and QCM chips by ultra violet polymerization to determine lower concentrations of amoxicillin. Ellipsometry, contact angle analysis, and atomic force microscopy measurements were used for the surface morphology of the polymeric film layer. The ellipsometric thickness of AMOX imprinted and nonimprinted SPR and QCM chip surfaces were measured as 35 ± 0.9 nm, 32.89 ± 1.9 nm, 30 ± 0.6 nm, and 28 ± 0.22 nm, respectively. Contact angles of bare gold surfaces, AMOX imprinted SPR and QCM chip surfaces were measured to be as 82.3° ± 0.15, 79.2° ± 0.14, 75.01° ± 1.07, and 69.11° ± 0.89, respectively. The range of linearity was measured as 0.1 to 10 ng/mL for amoxicillin imprinted SPR and QCM sensors. The maximum residue limit of AMOX in eggs is at 10 µg/kg in accordance with the “Positive List System for Agricultural Chemical Residues in Foods.” The response time for the test, including adsorption, desorption, and regeneration, was approximately 45 min. The limit of detections for SPR and QCM sensors were found to be 0.0005 and 0.0023 ng/mL, respectively. The reusabilities of amoxicillin imprinted SPR and QCM sensors were observed by the equilibration-binding-regeneration. Validation studies of the AMOX imprinted SPR and QCM sensors were performed by liquid chromatography-tandem mass spectrometry.     

人工模拟抗体在食品快速检测中的应斥及目前存在的问题

人工模拟抗体通过对天然的抗体以仿生学的模仿而人工合成的对目标分子具有特异性的分子识别能力的元件。人工模拟抗体是通过功能单体和交联荆对模板分子进行分子印迹而制备得到。因而，人工模拟抗体也叫分子印迹聚合体。由于分子印迹聚合体的活性的稳定性和低廉的价格，因此，在食品的快速检测上得到了应用，如兽药残留、农药残留、微生物的快速检测。但是，由于它一种新型的分子识别材料，存在的一些问题，如对大分子物质的识别不稳定等，还有待于进一步的改善。     

分子印迹技术在食品安全检测领域的应用进展

分子印迹技术所制备的分子印迹聚合物具有预定性、特异识别性、实用性、良好稳定性等特点,因此在食品安全检测领域得到广泛的应用。文章综述分子印迹技术的基本概念和原理,以及在食品农药残留、兽药残留、重金属污染、添加剂和生物性污染等方面检测应用的研究进展,比较分子印迹技术与传统固相萃取法所具有的优势,同时还分析分子印迹技术在食品安全检测领域中的问题和发展方向。     

Extraction and detection of morin from Sanghuangporus lonicericola by magnetic molecularly imprinted polymers coupled with HPLC analysis

In this study, morin magnetic molecularly imprinted polymers (Morin-MMIPs) were synthesized based on magnetic nanoparticles and surface molecularly imprinted technology with superparamagnetism and extraction selectivity. The polymers allowed the separating of morin from complex matrices in the presence of an external magnetic field with no need for centrifugation or filtration. The microstructure of the polymers was characterized by scanning electron microscopy and transmission electron microscopy. Meanwhile, the functional group and magnetic properties of the polymers were characterized using Fourier transform infrared spectroscopy (FT-IR) and magnetic vibration meter (VSM). The maximum adsorption capacity of MMIPs was 3.24 mg/g, which was 2.55 times higher than that of MNIPs (1.27 mg/g). Morin was quantified by HPLC-DAD, which showed good linearity in the concentration range of 0.05–60 µg/ml with the correlation coefficient R² = 0.9993. The limit of detection (LOD) was 0.08 µg/ml, and the spiked recoveries were 87.5–106.8%. The calculation of the adsorption isotherm and kinetic model revealed the adsorption mechanisms, and the adsorption process was consistent with the Langmuir adsorption isotherm and pseudo-secondary kinetic models. Likewise, the material has been successfully used to extract and separate morin from food samples. The method reported in this paper has the advantages of fast adsorption speed, high selectivity, and environmental friendliness. It provided a reliable method for the separation and detection of morin or other natural products.     

BOOK REVIEWS

Book Reviews in this Article:
FOOD FOR HEALTH IN THE PACIFIC RIM . Edited by J.R. Whitaker, N.F. Haard, C.F. Shoemaker and R.P. Singh. 1999. Food and Nutrition Press, Inc., Trumbull, CT. 611 pp. Hardcover. $140. ISBN:0917678-46-X.
STARCHES . David J. Thomas and William A. Atwell. Eagan Press Handbook Series. Eagan Press, St. Paul, Minn. 1999. ISBN 0-891127-01-2. Softcover. 94 pp. $59.
FISH SMOKING & DRYING: PRODUCTION AND QUALITY . Edited by Peter E. Doe. Technomic Publishing, Lancaster, Pennsylvania, 1998. 250 pages, 6 × 9 format, Hardbound, ISBN: 1-56676-668-0, $89.95.
LIPID OXIDATION . Edited by Edwin N. Frankel. The Oily Press Ltd., Dundee. 1998. 300 pp. ISBN 0951417193. Hardcover. $76.
SOURCE BOOK OF ENZYMES . John Stephen White and Dorothy Chong White. 1997. CRC Press LLC, Boca Raton, FL. 1306 pp. Hardcover. $99.95. ISBN 08493-9470-8.
NUTRICINES, FOOD COMPONENTS IN HEALTH AND NUTRITION . Clifford A. Adams. Nottingham University Press, Nottingham. 1999. ISBN 1-89767-90-5. 128 pp. Paperback. Illustrated. $19.50.     

分子印迹固相萃取技术及其在食品分析中的应用

分子印迹固相萃取(Molecularly Imprinted Solid Phase Extraction,MISPE)是一种重要的样品预处理技术,它具有选择性高、稳定性好和适用性广等特点。文章综述了分子印迹聚合物(MIPs)的制备原理、方法及其特点,MISPE的操作模式以及近几年该技术在食品中真菌毒素、农兽药残留、非法添加物质和环境污染物方面的应用。同时,对该技术在食品污染物分析中应用所存在的问题与今后的发展方面进行了展望。     

基于金属有机框架的农产品中农兽药残吸附萃取技术研究进展

农产品中农兽药物的残留是食品安全领域的主要问题之一,有必要对这些药物残留进行含量检测并严格限量。目前的吸附萃取材料如沸石、多壁碳纳米管等存在吸附量少、孔隙易堵塞的问题。金属有机框架（Metal-organic Frameworks,MOFs）因具有可调节孔隙、分级结构、巨大的孔体积和表面积、优异的吸附性能和可回收等特点而被逐渐应用于吸附萃取农产品中的农兽药残。本文综述了MOFs作为吸附剂吸附萃取农产品中农兽药残的应用现状,并分别从农、兽药种类的角度出发就MOFs的吸附应用进行了系统阐述,综合分析了MOFs的优异吸附性能。文章为MOFs吸附萃取农兽药残技术的进一步发展提供参考,为食品安全检测提供了技术借鉴。     

Synthesis and Evaluation of Molecularly Imprinted Polymers (MIP) with Affinity for the Polypeptide Nisin

The method of hierarchical imprinting was used for the first time in order to synthesize polymers with a high affinity for nisin. The concept of this approach is demonstrated by filling the pores of silica particles, which contain immobilized peptidic templates, with a mixture of monomers/initiator, followed by polymerization and subsequent dissolution of the silica template. This method leaves imprinted polymers with binding sites located at the surface that are capable of recognizing larger molecules with the same immobilized epitope. The results of the high-performance liquid chromatography analyses illustrate that the highest retention factors and imprinting factors of nisin on nisin C-terminal analogously imprinted polymers could be obtained with acetonitrile/water mixtures containing more than 80% water. Furthermore, nisin was strongly retained on polymers that were imprinted with a longer amino acid sequence because of better sterical accessibility of the binding sites for the C terminus of nisin. The retention of nisin (k = 21.65) under aqueous elution conditions results from selective ionic interactions and hydrophobic interactions. Furthermore, the polymers exhibited selectivity for the template Lys-Ala and the structurally related dipeptide Ala-Lys. The results of the present work show that these hierarchically imprinted polymers could be used for the chromatographic separation of the polypeptide nisin in aqueous solutions.     

Synthesis and utilisation of molecular imprinting polymer for clean-up of propachlor in food and environmental media

The molecularly imprinted polymers (MIPs) are used as the base material of solid phase extraction (SPE) for the separation and concentration of the propachlor herbicide (Prop) in different environmental matrix. Accordingly, we prepared MIPs on the surface of modified silica gel using propachlor as a template, acrylamide (AA) as functional monomers, ethylene glycol dimethacrylate (EGDMA) as a cross-linker and 2,2-azo-bis-isobutyronitrile (AIBN) as an initiator. The MIP structure was characterised using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Synthesised MIPs had a specific ability to detect the template Prop. The high selectivity solid phase extraction cartridges of molecularly imprinted polymers (MISPE) containing MIP Prop particles were prepared. The optimised Prop-MISPE procedure was developed for enrichment or clean-up of propachlor residues in water, soil and rice samples. Concentrations of propachlor in the samples were analysed by high performance liquid chromatography. Overall, the newly developed technique provides an analytical platform to quantify the trace amount of propachlor residues in multi or complex environmental and food media.     

BOOK REVIEWS

NUTRACEUTICALS: DESIGNER FOODS III GARLIC, SOY AND LICORICE . Paul A. Lachance, editor
THE CONCISE ENCYCLOPEDIA OF FOODS & NUTRITION . 2ND EDITION. Audrey H. Ensminger, M.E. Ensminger, James E. Konlande and John R.K. Robson, editors. 1995. CRC Press, Inc., 2000 Corporate Blvd., N. W., Boca Raton, Florida 33431 USA. 1184 pages. ISBN: 0–8493–4455–7. $139.00
TRACE ELEMENTS IN HUMAN NUTRITION AND HEALTH . WHO Expert Committee on Trace Elements in Food, Editorial Committee. 1996.
HANDBOOK OF FOOD ENGINEERING PRACTICE . Kenneth J. Valentas, Enrique Rotstein and R. Paul Singh, editors.
THE PESTICIDE MANUAL, INCORPORATING THE AGROCHEMICALS HANDBOOK, TENTH EDITION . Clive Tomlin, editor. 1994.
AGAINST THE GODS: THE REMARKABLE STORY OF RISK . Peter L. Bernstein. 1996.
PROCESSING VEGETABLES - SCIENCE AND TECHNOLOGY . Durward S. Smith, Jerry N. Cash, Wai-Kit Nip and Y.H. Hui, editors.
HANDBOOK OF BIOSENSORS AND ELECTRONIC NOSES-MEDICINE, FOOD, AND THE ENVIRONMENT . Erika Kress-Rogers, editor.
THE 9-POINT HEDONIC SCALE-DR. DAVID R. PERYAM'S EARLY PAPERS ON THE MOST WIDELY USED SENSORY SCALE IN THE WORLD . 1998.
WHEAT CHEMISTRY AND UTILIZATION . Hugh J. Cornell and Albert W. Hovelling. 1998.     

2015—2019年欧盟食品和饲料快速预警系统对华食品农兽药残留通报的数据分析

以2015年至2019年欧盟食品和饲料快速预警系统(rapid alert system for foodand feed, RASFF) 通报数据为基础, 对华通报的食品中农药兽药残留数据进行分析, 反映我国出口食品的质量安全状况。通过不同通报类型、通报国家、通报项目、采取措施等多维度数据对比进行了对华通报食品农兽药安全状况分析。结果显示农药残留依旧是制约我国农产品出口贸易的主要因素,不合格农药残留食品涉及的食品品种呈现出多元化的趋势,高剧毒农药的使用屡见不鲜。应通过制定完善的标准、治理种植养殖环境、强化监督管理等多措并举,降低出口贸易风险。     

合成印迹聚合物的新方法及在食品安全中的应用

分子印迹聚合物是一种具有专一识别作用的聚合物,具有预定型、识别性和实用性的特点,因此被广泛地应用在食品安全、农残分析和药物控制等方面。制备分子印迹聚合物除了本体聚合法、原位聚合法、悬浮聚合法、表面印迹等传统方法之外,还有原子转移自由基聚合法、可逆加成-断裂链转移自由基聚合等新方法。原子转移自由基聚合法、可逆加成-断裂链转移自由基聚合从化学角度实现了对自由基活性及其链增长反应的控制,具有高聚合物链端可控和修饰密度高等优点,为分子印迹聚合物的合成提供了有效的方法。本文重点综述了分子印迹聚合物传统合成方法、原子转移自由基方法和可逆加成-断裂链转移自由基聚合法及其在食品安全中的应用。     

QuEChERS法在食品有机污染物检测中的研究进展

食品中的农药残留、真菌毒素、兽药残留等有机污染物是危害食品安全的主要因素之一,因此,建立食品中多种有机污染物的高效提取和净化方法对于快速了解食品中有机污染物含量、保障食品安全具有十分重要的意义。本文在介绍QuEChERS(quick,easy,cheap,effective,rugged and safe)法及其近年来在食品有机污染物检测中的应用基础上,对其在应用过程中存在的问题进行了系统分析,提出该方法优化的一般思路,并展望了该方法在食品有机污染物检测中的未来发展趋势。     

Development of a Direct Competitive Biomimetic Enzyme-Linked Immunosorbent Assay Based on a Hydrophilic Molecularly Imprinted Membrane for the Determination of Trichlorfon Residues in Vegetables

In recent years, there has been an increasing demand on the determination of trace trichlorfon residues in fresh vegetables. In this study, a sensitive direct competitive biomimetic enzyme-linked immunosorbent assay (BELISA) method was developed for the determination of trichlorfon based on a hydrophilic imprinted membrane, which was directly synthesized on the well surface of MaxiSorp polystyrene 96-well plate through bulk polymerization technology. This novel imprinted membrane was characterized with high binding ability and specificity. Under the optimal conditions, the sensitivity (IC₅₀, half maximal inhibitory concentration) and the limit of detection (LOD, IC₁₅) of this method were 6800 ± 60 μg/L and 6.8 ± 0.20 μg/L, respectively. This BELISA method had been applied to the determination of trichlorfon with good recoveries ranging from 106.0 to 110.5%, and the results were correlated with that obtained by the gas chromatography method. Moreover, this method was applied to quantitative detection of trichlorfon residues in the leek samples.     

Maximum Residue Levels of Veterinary Medicines in Relation to Food Safety: European Community Legislation and Ethical Aspects

Residues of veterinary medicinal products, as defined by the European Union, are “pharmacologically active substances (whether active principles, excipients or degradation products) and their metabolites which remain in foodstuffs obtained from animals to which the veterinary medicinal product in question has been administered”. The policy for Maximum Residue Limit (MRL) setting is focused on a high protection level for the consumer. MRL can be set when risk assessment shows no risk for the consumer. An MRL is the maximum concentration of residue following administration of a veterinary medicine which is legally permitted or acceptable in food under the laws of the EU. The responsibility for keeping residues under the MRL lies with veterinarians and farmers, using licensed animal medicines. Violative residues of veterinary medicines can occur as a result of improper use of a licensed product or through the illegal use of an unlicensed substance. Consequently, it became clear that prudent use of not only antimicrobials used for treatment and prevention of disease but also those used for growth promotion (e.g. β-agonists or steroid hormones) in farm animals is an integral part of good veterinary practice. In the following an overview of the European Community legislation on the studies required for residues is given. Ethical aspects are also considered. Received: March 6, 2008; accepted: March 17, 2008     

磁性表面分子印迹聚合物对食品中苏丹红Ⅰ的检测

本文研究了一种对苏丹红Ⅰ的检测的新方法,即磁性表面分子印迹技术。主要是以包裹二氧化硅的磁性纳米颗粒为载体,在其表面合成对苏丹红Ⅰ有特异性识别的磁性表面分子印迹聚合物。利用紫外分光光度计、红外光谱分析仪及透射电子显微镜对于所制备的苏丹红Ⅰ磁性分子印迹聚合物的磁性、形态学功能、吸附性能和特异性进行检测。实验结果表明该磁性表面分子印迹聚合物的印迹位点位于磁性载体的表层,提高与目标物质的结合能力。在外磁场条件下,磁性表面分子印迹聚合物能够轻松地达到吸附平衡并实现磁分离,降低非特异性吸附,从而提高对苏丹红Ⅰ的吸附量和选择性。最后对辣椒中含有的苏丹红Ⅰ进行了回收率检测,回收率达到80%以上。说明采用磁性表面分子印迹法对食品中苏丹红Ⅰ可快速、高效的检测。     

分子印迹技术在食品中兽药残留分析中的应用

分子印迹技术以其高度的专一性和选择性广泛应用于食品安全检测和分析领域。由于食品基质复杂,传统的兽药残留检测前处理技术难度大、用时长,将分子印迹技术应用于食品中兽药残留检测技术中,很好地解决了上述问题。本文综述了分子印迹技术在食品中兽药残留分析中样品前处理技术、色谱分离技术、快速检测技术三方面的应用,对不同种类的兽药残留在检测过程中利用分子印迹技术的情况进行了分类和总结,对分子印迹技术在兽药残留分析过程中存在的问题和应用前景进行了归纳和展望。     

磁性分子印迹聚合物在天然活性物质分离纯化中的研究进展

磁性分子印迹聚合物是将磁性纳米粒子与分子印迹聚合物组装而成的一类新型分离材料,具有选择性高、易分离和易再生的特点,可被用于食品、药品检测前处理以及天然活性物质的分离纯化等领域。本文介绍了磁性分子印迹技术的制备原理和方法,重点综述了近5年（2017～2022）磁性分子印迹聚合物在多酚类、生物碱、有机酸、萜类以及生物大分子化合物等天然活性物质的分离纯化方面的研究进展,并针对当前分离纯化领域的研究难点进行了讨论,以期为高值化、低含量的天然活性成分的富集、纯化及其分析检测提供研究参考。     

分子印迹技术在动物源性食品安全检测中的应用

动物源性食品中的兽药残留对环境和公众的健康构成的潜在危害越来越受到重视。分子印迹技术(MIT)具有优越的识别性和选择性,在食品安全检测中具有重要的研究潜力。本文综述了分子印迹技术的产生与发展、分子印迹的原理及其在兽药残留检测中的应用,并对该技术的应用前景进行了展望。     

A Fast, Simple, and Reliable High-Performance Liquid Chromatography (HPLC) Method for Determining Abamectin Residues in Vegetables and Fruits

This paper describes a simplified high-performance liquid chromatography method without clean-up step for the determination of abamectin residue in non-fatty vegetables and fruits. The abamectin residues were extracted efficiently with acetonitrile assisting by ultrasound and then directly derivatized without requiring the clean-up step. Results showed that the developed method has good sensitivity and selectivity for determining the abamectin residues in vegetables and fruits. Limits of detection and limits of quantification were 0.0005 and 0.002 μg/g, respectively. The recoveries ranged from 83.2% to 123.7% with satisfactory precision (RSD < 16.7%) and bias (−16.8 ∼ 23.7%). The proposed method was successfully applied to analyze the real commercial samples.