超高效液相色谱-串联质谱法测定动物源性食品中硝基咪唑类药物及其代谢物的残留量的研究

目的建立超高效液相色谱-串联质谱法测定动物源性食品中硝基咪唑类药物及其代谢物的分析方法。方法试样经三氯乙酸溶液提取, MCX固相萃取小柱净化, 5%的甲醇水(V/V)溶液复溶。电喷雾正离子模式电离,多反应监测模式检测,基质匹配内标法定量。结果硝基咪唑及其代谢物在0.25～50 ng/mL范围内线性关系良好,相关系数均大于0.9915,加标回收率为73.5%～120.4%;相对标准偏差在2.4%～13.4%之间,定量限为0.1～0.5μg/kg。结论本方法简便、灵敏,适用于动物源性食品中硝基咪唑类药物及其代谢物残留的定性、定量分析。     

超高效液相色谱-串联质谱法快速检测水产品中硝基呋喃类代谢物残留研究

以水产品中的硝基呋喃类代谢物残留为研究对象,建立超高效液相色谱-串联质谱(UPLC-MS/MS)测定水产品中硝基呋喃类代谢物残留分析方法。结果显示:硝基呋喃类代谢物在1. 0～100. 0 ng/mL的范围内线性关系良好,相对回收率为86. 2%～108%,相对标准偏差为3. 4%～9. 6%,检出限为0. 25μg/kg,定量限为0. 5μg/kg。与以往采用的超高效液相色谱-串联质谱方法相比,新建方法操作简单、快速、准确,是定量检测水产品中硝基呋喃类代谢物残留的有效技术手段。     

固相支撑液液萃取-平行蒸发前处理技术测定动物源性食品中4种硝基呋喃类代谢物

硝基呋喃类药物的检测常以其代谢物为目标物,建立了鸡肉、蜂蜜、牛奶中呋喃唑酮代谢物(AOZ)、呋喃它酮代谢物(AMOZ)、呋喃妥因代谢物(AHD)和呋喃西林代谢物(SEM)检测的超高效液相色谱串联质谱确证方法,硝基呋喃代谢物经衍生化后,采用硅藻土固相支撑液液萃取和平行蒸发联用前处理技术进行净化和富集衍生物,超高效1.7μm C18柱用于分离4种待测物,同位素内标法定量。AOZ和AMOZ为最低检测限为0.1μg/kg,AHD和SEM为0.25μg/kg。3个不同添加水平时该方法回收率为85.6%～104.3%,相对标准偏差(RSD)为3.2%～9.5%,通过对实际样品进行测定,结果表明该方法能简单、快速、准确地测定动物源性食品中4种硝基呋喃类代谢物。     

液相色谱-串联质谱法同时检测鱼中氯霉素类和硝基咪唑类药物残留

本实验建立了同时检测鱼肉中3种氯霉素类和5种硝基咪唑类药物残留的液相色谱-串联质谱方法。采用乙酸乙酯提取,提取液浓缩后纯水定容,正己烷脱脂,在优化的液相色谱条件下,3种氯霉素类和5种硝基咪唑类药物在8 min内实现良好分离。氯霉素类检出限均为0.1 μg/kg,甲硝唑检出限为0.5 μg/kg,其他硝基咪唑类均为1.0 μg/kg。在线性范围(氯霉素类0.5～50.0 μg/L,硝基咪唑类2.0～100.0 μg/L)内,相关性良好,相关系数r>0.996 0,空白基质3个添加水平的平均回收率为82.3%～109.0%,相对标准偏差(n=6)为3.6%～12.0%。本方法经济、快速、简单和高效,能同时满足鱼肉中3种氯霉素类和5种硝基咪唑类药物残留的检测要求。     

高效液相色谱串联质谱法测定牛奶中左旋咪唑的残留量

目的建立高效液相色谱串联质谱法测定牛奶中左旋咪唑的残留量。方法牛奶样品用碱性乙酸乙酯提取,经振荡、离心、旋转蒸发后,再经盐酸提取,上清液经MCX固相萃取柱净化,氨化甲醇洗脱,氮气吹干,乙腈水定容,过0.22μm有机滤膜,高效液相色谱-串联质谱测定,多反应监测(multiple reaction monitoring,MRM),外标法定量。结果左旋咪唑在0～20ng/mL的浓度范围内线性关系良好,相关系数为0.995,牛奶中左旋咪唑检出限为0.4μg/kg,加标回收率为82.33%～104.49%,相对标准偏差均小于7%。结论该方法前处理简便快速,灵敏度高,适用于牛奶中左旋咪唑残留量的检测。     

超高效液相色谱-串联质谱法测定鸡肉中羟基甲硝唑和羟甲基甲硝咪唑残留量

本文建立了高效液相色谱-串联质谱法检测鸡肉中两种硝基咪唑代谢产物——羟基甲硝唑和羟甲基甲硝咪唑的分析方法。样品经乙腈提取,正己烷除脂,Retain-CX固相萃取柱净化,以0.1%甲酸水溶液和乙腈作为流动相梯度洗脱,C18色谱柱分离,正离子模式电喷雾电离,多反应监测(MRM)测定鸡肉中羟基甲硝唑和羟甲基甲硝咪唑含量。在5.0～200ng/mL范围内,两种代谢物的线性关系良好,相关系数(r2)大于0.997,检出限为0.13～0.16μg/kg,定量限为0.43～0.53μg/kg,在1.0μg/kg、5.0μg/kg、10μg/kg这3个加标浓度下的回收率为76.0%～109.8%,相对标准偏差为2.7%～14.5%(n=6)。这说明,该方法准确、高效,适用于鸡肉中羟基甲硝唑和羟甲基甲硝咪唑的检测。     

超高效液相色谱-串联质谱法测定保健食品中90种那非类药物

建立高效液相色谱-串联质谱检测保健食品中90种那非类药物的分析方法。样品经甲醇直接提取,用Waters Acquity BEH C18柱(2.1 mm×100 mm,2.5μm)分离,以0.1%甲酸溶液和乙腈为流动相进行梯度洗脱,多反应模式监测,外标法定量。结果表明:90种那非类药物在0.2～50 ng/mL质量浓度范围内线性关系良好,相关系数大于0.995;检出限范围为2.5～25.0μg/kg;定量限范围为5.0～50.0μg/kg;加标水平为5.0～500μg/kg时,回收率范围为78.0%～109.9%;相对标准偏差小于10%;此方法简便快速、选择性强、灵敏度高,可用于保健食品中90种那非类药物的测定。     

超高效液相色谱串联质谱同时测定豆芽、豆干、火锅底料中喹诺酮类、磺胺类、硝基咪唑类、四环素类42种抗生素药物

目的 建立并优化同时测定豆芽、豆干、火锅底料中喹诺酮类、磺胺类、硝基咪唑类、四环素类共42种抗生素的超高效液相色谱串联质谱检测方法。方法 样品经70%乙腈-水(含0.1%甲酸)提取后,经PRiME HLB净化,采用Agilent Eclipse Plus C₁₈柱(150 mm×3.0 mm,1.8μm)进行分离,以0.2%甲酸乙腈和0.2%甲酸水为流动相梯度洗脱,采用电喷雾离子源正离子动态多反应监测模式测定,外标法定量。结果 豆芽、豆干、火锅底料基质中喹诺酮类、磺胺类、硝基咪唑类药物的线性范围为2～80 ng/mL,方法检出限均为5μg/kg;四环素类药物的线性范围为10～400 ng/mL,方法检出限均为25μg/kg;相关系数均大于0.997。42种抗生素在三个加标水平下平均回收率为85.4%～119.3%,相对标准偏差(n=6) 0.4%～13.4%。结论 该方法应用范围广、操作简便,灵敏度高,可对豆芽、豆干、火锅底料中喹诺酮类、磺胺类、硝基咪唑类、四环素类多种抗生素药物的浓度进行快速筛查。     

通过式固相萃取-超高效液相色谱串联质谱法快速测定中兽药制剂中４种硝基咪唑类药物

目的建立通过式固相萃取-超高效液相色谱串联质谱法(ultra performance liquid chromatographytandem mass spectrometry,UPLC-MS/MS)同时快速测定中兽药制剂中4种硝基咪唑类药物的方法。方法样品(2.0 g)经乙醇超声提取,采用PRiME HLB固相萃取柱净化,以0.1%甲酸溶液和乙腈为流动相,ACQUITY BEH C18色谱柱分离,电喷雾正离子扫描,多反应监测模式进行液相色谱串联质谱检测。结果 4种目标化合物在1～100 ng/mL范围内线性良好,相关系数r~20.999。在3个加标水平(25、50和250μg/kg)下,4种化合物的平均回收率范围为70.0%～93.8%,相对标准偏差范围为1.2%～13.0%。方法的检出限为10μg/kg;定量限为25μg/kg。结论该方法操作简便、灵敏度高,可满足中兽药制剂中硝基咪唑类药物的监测需求。     

猪肉中硝基咪唑类药物残留快速测定方法

该试验旨在建立高效液相色谱-串联质谱法快速测定猪肉中硝基咪唑类药物残留。样品用乙腈(含0.2%甲酸)提取,然后经过净化处理,目标物在液相系统进行洗脱分离,并使用质谱电喷雾电离源正扫描模式进行检测。优化了色谱流动相条件以及样品提取液的净化处理方式,在优化条件下, 4种硝基咪唑类药物在1.0～25 ng/m L浓度范围内表现出较好的线性关系,相关系数≥0.991;在3个水平(0.25, 0.5和2.5μg/kg)的加标试验中,回收率范围和相应的标准偏差(n=6)分别为:76.7%～105.6%, RSD≤13.9%; 84.0%～107.1%, RSD≤4.2%; 87.8%～102.0%, RSD≤2.5%。该方法具有良好的准确度和精密度,且检出限较低(0.25μg/kg),能够满足日常快速检验的需求。     

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