基于NiO@Pt-离子液体/玻碳电极传感器检测肉制品中的亚硝酸盐

目的 制备了新型的NiO@Pt-AVIMBF₄/GCE传感器对肉制品中的亚硝酸盐进行快速分析。方法 在氧化镍纳米材料(Nickel oxide nanomaterials, NiO)基础上合成了NiO@铂纳米材料(Platinum nanomaterials, Pt),并复合1-乙烯基-3氨丙基咪唑四氟硼酸盐(APVIMBF₄)离子液体,制备了新型的NiO@Pt-AVIMBF₄,采用玻碳电极(Glassy carbon electrode, GCE)构建新型的NiO@Pt-AVIMBF₄/GCE传感器,通过对NiO@Pt-AVIMBF₄、静置时间等条件的优化,确定NiO@Pt-AVIMBF₄/GCE的最佳检测条件,对肉制品中的亚硝酸盐进行定量分析。结果 研究发现,NiO@Pt-AVIMBF₄具有良好的导电性、催化性和生物相容性能有效提高传感器的灵敏度,亚硝酸盐浓度与氧化峰电流在0.1~1100 μmol/L呈线性关系, R^₂=0.998,检出限0.019 μmol/L (S/N=3)且对实际样品的检测结果与国标规定方法检测结果一致。NiO@Pt-AVIMBF4/GCE重复性、重现性、稳定性良好,而且对常见干扰物质具有很好地抗干扰能力。结论 制备的NiO@Pt-AVIMBF₄/GCE简便、快捷,实用性强可应用于亚硝酸盐的快速定量分析。     

基于新型金属有机框架模拟酶的电化学检测食品胆固醇体系的构建

基于金属有机框架具有模拟酶的特性,构建实时检测胆固醇电化学传感器。采用自组装的方法制备出新型的复合金属有机框架模拟酶(Fe₃O₄@Au/MOF)纳米粒子,其兼具了Fe₃O₄磁性粒子的可回收特点以及金纳米粒子的加速电子转移等优点。并利用红外光谱、透射电子显微镜以及X射线光电子能谱对制备成功的Fe₃O₄@Au/MOF的结构和形貌进行表征。借助Fe₃O₄@Au/MOF的类过氧化物酶双重催化性能使胆固醇氧化为胆甾烯三酮和H₂O₂,而H₂O₂在其进一步的催化下产生的具有氧化活性的羟基自由基可促进3,3′,5,5′-四甲基联苯胺发生氧化还原反应,进而增加了体系中电荷的移动。根据电信号的响应情况, 从而实现对胆固醇的快速定性和高效定量的检测。研究结果表明,采用循环伏安法测得优化检测体系为:反应温度为 50℃,Fe₃O₄@Au/MOF 添加量为0.0125g,扫描速率为0.10V/s,缓冲溶液pH=4；当胆固醇浓度处于0.001~1.500mmol/L时呈现良好的线性关系,线性回归方程为y=20.6401x+4.7722,R²=0.9956,最低检测限为2.7μmol/L；且检测体系具有良好的回收率和抗干扰性,在食品分析和生化分析等方面具有良好的应用前景。     

基于Fe3O4@C/\[BSMIM\]HSO4/GCE传感器检测铅离子

目的：采用Fe₃O₄@C/\[BSMIM\]HSO₄/GCE对水中的铅离子进行定量分析。方法：在四氧化三铁（Fe₃O₄）的基础上,制备了具有核壳结构的Fe₃O₄@C纳米复合材料,并复合1-甲基-3-丁磺酸基咪唑硫酸氢盐 （\[BSMIM\]HSO₄）离子液体,以玻碳电极（Glassy carbon electrode,GCE）为载体,制备了Fe₃O₄@C/\[BSMIM\]HSO₄/GCE,并利用其对饮用水中铅离子进行定量分析。结果：Fe₃O₄@C具有良好的导电性和分散性,Fe₃O₄@C/\[BSMIM\]HSO₄/GCE具有较好的电化学稳定性和电催化活性。利用Fe₃O₄@C/\[BSMIM\]HSO₄/GCE对饮用水中铅离子进行定量分析,铅离子浓度与峰电流在0.1～80.0 μg/L内呈良好的线性关系,R²=0.999 5,检出限为0.038 μg/L （S/N=3）,检出限较低,其加标回收率在97.60%～100.93%,回收效果较好,准确度较高。且该传感器重复性较好,连续差分脉冲扫描10次其相对标准偏差为2.446%。结论：该方法简单、快捷、可靠,为饮用水中铅离子的检测分析提供了一种新的解决方案。     

基于掺杂型石墨烯量子点构建关—开型电化学发光传感器连续检测Fe3+和F-

目的：研究石墨烯量子点的电化学发光性能。方法：制备发光强度高、性能稳定的氮硫掺杂石墨烯量子点（NS-GQDs）,并构建关—开型电化学发光（ECL）传感器以实现对Fe³⁺和F-的连续检测。结果：在0.1~460.0 μmol/L范围内,Fe³⁺浓度与ECL猝灭值呈良好的线性关系,检出限为0.028 μmol/L;在1~5 600 μmol/L范围内,F^-浓度与ECL恢复值呈良好的线性关系,检出限为0.62 μmol/L。结论：NS-GQDs ECL信号的猝灭和恢复具有较好的可逆性,可应用于饮用水中Fe³⁺和F^-的连续检测。     

碱木质素碳点的制备及对Fe3+检测性能研究

以碱木质素（Alkali lignin,AL）为碳源、乙二胺（Ethanediamine,EDA）为钝化剂、双氧水（H₂O₂）为氧化剂,利用简单、绿色、高效的水热法制备碱木质素碳点（ALE-CDs）。以荧光性能为指标,通过单因素实验优选出ALE-CDs的最佳制备工艺。结果表明,ALE-CDs表面存在大量的羟基（—OH）、羧基（—COOH）和氨基（—NH₂）等官能团,在水中具有优良的分散性和稳定性,荧光量子产率及寿命分别为19.20%和6.03 ns。利用ALE-CDs为荧光探针检测不同金属离子,发现ALE-CDs对Fe³⁺表现出较好的选择性,荧光强度与Fe³⁺浓度（0~50 μmol/L）呈良好的线性关系,Fe³⁺检出限约为1.66 μmol/L。     

磺胺二甲嘧啶间接竞争化学发光酶免疫分析法的建立及应用

建立一种更加灵敏的磺胺二甲嘧啶(SM₂)免疫学检测方法。方法 本研究制备抗SM₂单克隆抗体(SM₂-mAb),用于建立SM₂间接竞争化学发光酶免疫分析法(SM₂-CLEIA),并检测主要动物食品中SM₂残留。结果 本研究制备的SM₂-mAb为IgG_2b亚类,亲和常数为0.12×10⁷ L/mol;SM₂-CLEIA曲线在0.1～1 000 μg/L之间呈现良好的线性关系,相关系数r²=0.990 4,半数抑制浓度(IC₅₀)为4.006 μg/L,检测限为0.174 μg/L,添加回收率为94.41%～104.40%,批内和批间变异系数分别为3.07%和8.22%,与磺胺脒等药物无交叉反应,与SM₂-ELISA试剂盒的阴阳性符合率为100%。结论 建立了灵敏、特异、准确、检测范围宽的SM₂-CLEIA检测方法。     

体外模拟人肠道微生物对葡萄酒花色苷稳定性的影响

目的 研究miR-499a-5p对过氧化氢(H₂O₂)诱导的心肌细胞H9c2增殖、凋亡的影响,并探讨其作用机制。方法 用细胞计数试剂盒(CCK-8)检测不同浓度H₂O₂(100、200、400、800 μmol/L)处理6 h的H9c2细胞的存活率,筛选400 μmol/L H₂O₂处理的H9c2细胞作为模型组。将模型组细胞分为miR-NC组、miR-499a-5p组、si-NC组、si-APC组、miR-499a-5p+pcDNA组、miR-499a-5p+pcDNA-APC组,用流式细胞术、免疫印迹(Western blot)、酶联免疫吸附试验(ELISA)检测各组细胞的存活率、凋亡率、活性氧(ROS)、超氧化物歧化酶(SOD)、丙二醛(MDA)及增殖凋亡相关蛋白增殖细胞核抗原(PCNA)、细胞周期蛋白依靠性激酶抑制剂(P21)、B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关的X基因(Bax)的表达。结果 H₂O₂(100、200、400、800 μmol/L)呈浓度依赖性抑制H9c2细胞的存活,最适浓度为400 μmol/L。模型组细胞中miR-499a-5p表达显著降低,APC表达显著升高;过表达miR-499a-5p、抑制APC均可明显减轻H₂O₂诱导的H9c2细胞的增殖抑制、凋亡促进和氧化应激作用,并且miR-499a-5p还可靶向抑制APC。过表达APC逆转了miR-499a-5p对H₂O₂诱导的心肌细胞损伤。结论 miR-499a-5p可调控H₂O₂诱导的心肌细胞增殖、凋亡和氧化应激,其机制与靶向抑制APC有关,将可为氧化应激引起的心肌细胞损伤的治疗提供新靶点。     

基于Pd/MWCNTs/玻碳电极的电化学传感器检测水样中的羟胺

目的 采用Pd/MWCNTs纳米复合材料修饰玻碳电极构建电化学传感器,检测养殖水样及水产饲料中羟胺（NH2OH）的含量。方法 采用乙二醇还原法制备Pd纳米颗粒负载于碳纳米管上制备Pd/MWCNTs纳米材料,运用XRD(X-ray diffraction)和TEM (transmission electron microscopy) 手段对材料进行表征,构建基于Pd/MWCNTs/GCE的电化学传感器检测羟胺。 结果 在优化的工作条件下,Pd/MWCNTs纳米复合材料修饰电极检测羟胺线性检测范围2.0 μmol/L-1.4 mmol/L,检测下限达0.60 μmmol/L (S/N = 3),灵敏度为61.48 μA/mmol/L,是MWCNTs修饰电极检测灵敏度的10倍左右。结论 复合材料制备的传感器检测羟胺具有灵敏度高、线性范围宽、检测下限低的特点,可用于抗氧化剂羟胺的检测。     

基于柔性集成三电极和智能手机的便携传感器快速检测磺胺甲噁唑

目的 制备一种对磺胺甲噁唑(Sulfamethoxazole,SMZ)有检测性能的柔性集成三电极,构建基于智能手机和柔性电极的便携式传感方法,使其能用于现场快速检测牛奶样品中的磺胺类残留。方法 以聚酰亚胺(Polyimide,PI)薄膜为基底,采用激光诱导刻蚀技术制备激光诱导多孔石墨烯(Laser-induced porous graphene,LIPG)柔性集成三电极。以LIPG为工作电极和对电极、以滴涂Ag/AgCl油墨的LIPG为参比电极;将制备好的LIPG柔性集成三电极插入mini电化学工作站接口,mini工作站与智能手机蓝牙连接,构建智能便携式传感器。在浓度为50 μmol/L的SMZ溶液中采用循环伏安法(Cyclic Voltammetry,CV)和差分脉冲伏安法(Differential Pulse Voltammetry,DPV)对比研究SMZ在LIPG电极上的电化学行为;研究了LIPG电极的有效面积、重现性、稳定性及抗干扰能力等。结果 本方法制备的LIPG三电极具有较好的重现性、稳定性和抗干扰性。在8.75 – 55.0 μmol/L的浓度范围内,SMZ浓度与峰电流呈现出良好的线性关系,R₂^为0.9985,检出限为2.87 μmol/L。实际样品添加回收率在99.0% – 100.5%之间,相对标准偏差(Relative standard deviation,RSD)分别为2.49%和0.77%。结论 本研究制备的LIPG柔性集成三电极可以替代传统刚性三电极构建智能便携式传感方法。以智能手机为操作界面,不仅携带方便、操作简便,而且响应速度快,适用于现场快速检测。     

仿刺参精、卵多肽体外抗氧化及对H2O2诱导巨噬细胞氧化损伤的保护作用

目的 为研究仿刺参精、卵多肽体外抗氧化及对H₂O₂诱导巨噬细胞氧化损伤的保护作用。方法 采用切向流超滤法对多肽进行分级制备,通过测定清除1,1-二苯基-2-苦基苯肼自由基(DPPH.)、羟基自由基(.OH)和超氧阴离子自由基(O_2^-.)的能力来评价体外抗氧化活性,并对多肽的相对分子质量(Mr)、氨基酸(AA)组成及氧化稳定性进行检测分析,通过构建氧化损伤细胞模型,考察多肽对H₂O₂诱导RAW 264.7巨噬细胞氧化损伤的保护作用。结果 仿刺参精、卵多肽均具有较强的清除DPPH.、.OH和O_2^-.能力,并且在一定范围内呈现量效关系,Mr<1×10^₃ Da的多肽AJS1和AJE1抗氧化活性表现更强,两者Mr 95.56%和91.89%在1×10^₃ Da以内,疏水性AA和酸性AA比例均较高,并具有极佳的耐盐性和热稳定性,但在贮存和加工过程中仍要注意过酸环境和金属离子对氧化稳定性的影响。所有多肽组对巨噬细胞不存在毒性影响,并且多肽质量浓度为200、400 μg/mL时均对H₂O₂损伤的RAW 264.7巨噬细胞体现出显著的保护作用(P<0.05)。结论 仿刺参精、卵多肽具有良好的体外抗氧化和对氧化损伤细胞的保护作用,具有开发为功能性食品、医药和化妆品等的潜力。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press