分子印迹固相萃取膜-高效液相色谱法检测粮谷中的三唑类杀菌剂

本文建立了同时分离检测粮谷样品中4种三唑类杀菌剂的分子印迹固相萃取膜-高效液相色谱法。采用自制的联苯三唑醇分子印迹固相萃取膜对粮谷中的联苯三唑醇、三唑酮、烯唑醇和戊唑醇残留进行分离富集,并采用高效液相色谱法测定其在粮谷样品中的残留。试验对淋洗剂、洗脱剂的种类和用量以及检测条件进行了优化。以5 m L水为淋洗剂,3 m L甲醇为洗脱剂,使用C18色谱柱,以甲醇-水(体积比为82:18)溶液为流动相,紫外检测波长为210 nm,外标法定量。结果表明,4种杀菌剂平均回收率在84.2%~98.1%之间,相对标准偏差(RSDs)在1.2%~2.7%之间(n=5)。该分子印迹固相萃取膜不仅对样品净化效果好,而且对4种杀菌剂特异吸附能力强。该方法能高效、快速、灵敏检测粮谷样品中三唑类杀菌剂。     

基于Fe3O4@MIL-100(Fe)@Ag NPs的三唑磷SERS检测方法

针对在农产品中简便、快速地检测农药三唑磷残留问题，建立基于磁纳米、金属有机框架和Ag纳米颗粒(Ag NPs)的核-壳-卫星纳米结构表面增强拉曼光谱(surface-enhanced Raman scattering,SERS)基底，并应用在有机磷农药三唑磷的灵敏检测。通过低温循环自组装法和银镜循环制备了由MIL-100(Fe)包覆的Fe₃O₄，并在表面原位负载Ag NPs组成的核-壳-卫星纳米结构的Fe₃O₄@MIL-100(Fe)@Ag NPs基底。对苹果中的三唑磷残留进行SERS传感，三唑磷特征峰强度对数值与质量浓度对数值的线性检测范围为0.05～10 mg/L，线性方程为Y=0.573 8X+2.804(R²=0.980)，检出限低至11.9μg/L。在加标量为2、5、10 mg/L时，该方法的回收率为90.07%～103.27%。表明制备的SERS基底在食品农残中的检测领域具有巨大潜力。     

联苯三唑醇磁性分子印迹聚合物的制备及其在食品检测中的应用

采用表面印迹技术,以表面接枝硅烷偶联剂KH570的Fe₃O₄@SiO₂微球为磁性载体,联苯三唑醇为模板分子,建立制备联苯三唑醇磁性分子印迹聚合物(magnetic molecularly imprinted polymer,MMIP)的方法。采用红外光谱、透射电子显微镜、磁响应性能测定等方法对优化条件下制备的聚合物进行表征;通过静态吸附实验考察聚合物对模板分子的吸附能力;并以该聚合物作为固相萃取材料,对小米、小麦等样品中的目标物质进行固相萃取,同时使样品得以净化,并采用高效液相色谱法对样品中目标物进行检测。结果表明,制备的核-壳结构联苯三唑醇MMIP对联苯三唑醇和其结构类似物具有分子识别能力,所建检测方法的线性关系好(r≥0.999 6),检出限为0.01～0.02μg/mL,平均回收率在87.7%～104.3%之间,相对标准偏差为1.39%～3.46%(n=5)。该MMIP适用于食品中三唑类农药的快速分离和净化,其检测方法能选择性地快速分析食品中三唑类农药残留量。     

脐橙果皮中三唑磷农药残留的表面增强拉曼光谱快速检测研究

采用表面增强拉曼光谱技术结合化学计量方法快速分析脐橙果皮中的三唑磷农药残留。利用乙腈快速提取脐橙果皮的提取液,采用石墨化碳、C18和PSA去除果皮提取液中色素等物质的干扰。以脐橙果皮提取液为基质,配制不同浓度的三唑磷农药溶液,进行拉曼信号采集,得到的拉曼特征峰与三唑磷标准溶液的特征峰基本一致。建立脐橙果皮中三唑磷农药残留的偏最小二乘法预测模型,结果表明,以脐橙果皮提取液为基质的三唑磷溶液最低检测浓度为0.8 mg/L;模型对预测集样本的预测均方根误差为1.60 mg/L,相关系数为0.9669。再利用该方法检测脐橙中实际所含三唑磷农药残留,其模型对样本的预测值与真实值的相对误差绝对值在0.08%~5.98%之间,预测回收率为94.36%~104.36%,模型预测能力和重现性良好。     

基于SERS技术的脐橙果肉中三唑磷农药残留快速检测研究

采用表面增强拉曼光谱（SERS）技术结合快速溶剂前处理方法建立脐橙果肉中三唑磷农药的快速检测方法。以脐橙果肉为空白对照,利用快速溶剂前处理方法对脐橙果肉进行提取,对不同浓度的以脐橙果肉提取液为基质的三唑磷溶液进行SERS检测。结果表明,以脐橙果肉提取液为基质的三唑磷溶液最低检测浓度为0.5mg/L;选择乙腈为内标物,以三唑磷1409cm-1特征峰与乙腈2257cm-1特征峰强度比值作为相对强度,其相对强度与三唑磷溶液浓度在0.5²0mg/L范围内具有良好的线性关系,相关系数（R2）为0.9919;预测误差在0.12mg/L以下,预测回收率为98.1%¹02.5%,说明模型具有较好的预测效果,本文所建立的方法是准确可靠的。      

搅拌棒萃取-气相色谱法检测大蒜及蒜粉中三唑磷残留

建立了搅拌棒萃取-气相色谱法检测大蒜及蒜粉中三唑磷农药残留。样品经搅拌棒萃取,解析液解析后,上机检测。采用Rtx-1701(30 m×0.25 mm×0.25 m)色谱柱分离,在程序升温的模式下检测,外标法定量。结果表明,三唑磷农药在质量浓度1.5~200μg/L范围内线性关系良好,相关系数r=0.998 3,方法的定量限为1.5μg/kg。在不同添加水平下,其平均回收率为71%~97%,变异系数为5.8%~10.8%。该方法简便、快捷,适用于大蒜及蒜粉中三唑磷的检测。     

混合三模板分子印迹固相萃取柱应用于粮谷中三唑类农药的检测

建立了采用混合三模板分子印迹固相萃取-高效液相色谱法分离检测粮谷样品中3种三唑类杀菌剂残留的方法。以联苯三唑醇、腈菌唑、烯唑醇为混合模板分子,采用本体聚合法合成了具有高选择性的混合三模板分子印迹聚合物,以该聚合物为填料制备混合三模板分子印迹固相萃取柱,并结合高效液相色谱法检测粮谷中联苯三唑醇、腈菌唑、烯唑醇残留。结果表明,以20 mL水为淋洗剂,15 mL甲醇为洗脱剂,并在最佳色谱条件下,联苯三唑醇、腈菌唑、烯唑醇的平均回收率分别为74.0%~82.4%、79.0%~86.2%、77.5%~85.1%,相对标准偏差(RSD)≤4.4%,该混合三模板分子印迹聚合物对3种杀菌剂具有特异性吸附能力,该分析方法可用于样品中三唑类杀菌剂残留的分离检测。     

三唑磷在稻米中的残留及其加工影响与膳食暴露评估

采用田间喷药、室内模拟加工和气相色谱检测的方法,研究三唑磷在稻米中的残留,蒸煮的影响及其膳食暴露评估。研究结果表明,三唑磷在稻米中的残留量与喷药剂量、次数和间隔期有关,如在推荐剂量时,三唑磷在糙米和精米中的残留量范围分别是0.020~0.214mg/kg和0.007~0.074mg/kg;而1.5倍剂量时,分别为0.041~1.404mg/kg和0.01~0.075mg/kg。淘洗、电饭煲、微波炉和高压锅蒸煮能够降低稻米中三唑磷残留量,与糙米原料的残留量差异显著(p<0.05)。不同蒸煮方式间的影响差异性不显著(p>0.05)。一般是低龄人的膳食风险商高于年龄大的,男性膳食风险商范围为2.71%~68.24%,而女性为2.55%~71.67%。考虑到淘洗和蒸煮因素,风险商降低6.6%~34.1%。糙米中三唑磷残留量高于精米的,各处理间隔期为60d时的残留量低于国家标准(0.05mg/kg)。淘洗和蒸煮能够降低稻米中三唑磷残留量。通过稻米膳食摄入三唑磷的风险商在安全范围内。     

基于新型磁性固相萃取材料结合高效液相色谱法检测食品中碱性橙Ⅱ和柠檬黄

以Fe3O4/P(St-4-VP)为磁性固相萃取材料,建立高效液相色谱法测定腐竹中碱性橙Ⅱ和苦荞茶中柠檬黄的分析方法。方法 通过溶液pH、吸附时间、吸附方式、吸附剂用量和材料组成配比5个因素,优化了Fe3O4/P(St-4-VP)对色素的最佳吸附条件。通过等温吸附实验探究了Fe3O4/P(St-4-VP)的吸附模型。在优化的吸附条件下,结合高效液相色谱法定量分析了腐竹中的碱性橙Ⅱ和苦荞茶中的柠檬黄。结果 Fe3O4/P(St-4-VP)对色素的最佳吸附pH：碱性橙Ⅱ为pH 7.0,柠檬黄为pH 3.0;最佳吸附时间、吸附方式、吸附剂用量和材料组成配比分别为5 min、振荡吸附、1.0 mg和Fe3O4:P(St-4-VP) (m:m)=2:1。Fe3O4/P(St-4-VP)对碱性橙Ⅱ和柠檬黄的吸附过程均符合Langmuir等温吸附模型,最大吸附载量分别为116.5 ?g/mg和183.8 ?g/mg。将该材料应用于腐竹中碱性橙Ⅱ和苦荞茶中柠檬黄的检测,加标回收率为94.26%~101.04%,相对标准偏差为1.12%~3.35% (n=6)。结论 Fe3O4/P(St-4-VP)对碱性橙Ⅱ和柠檬黄色素有较好的吸附性,可快速将色素从样品中分离,洗脱方便可回收,可用于腐竹中碱性橙Ⅱ和苦荞茶中柠檬黄的检测。     

Fe3O4@COF磁性共价有机框架材料的制备及吸附多溴联苯醚性能研究

目的 在室温下合成了核壳结构磁性共价有机骨架,结合磁性固相萃取用于水样中多溴二苯醚的吸附。方法 通过透射电子显微镜、扫描电子显微镜、傅里叶变换红外光谱、X射线衍射和振动样品磁强计对制备的材料进行了表征。结果 表明Fe3O4@COF磁性纳米材料具有良好的结晶度,磁性纳米颗粒表面包裹22μm左右厚的COF材料,在吸附多溴二苯醚上具有良好的动力学性能,吸附量可达32.87mg/g。结论 Fe3O4@COF磁性纳米材料是一种优异的吸附剂,可用于多溴联苯醚的吸附。     

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