磁性分子印迹固相萃取食品中的四环素类抗生素残留

采用表面分子印迹技术合成对四环素类抗生素具有特异性吸附性能的Fe3O4@Si O2@MIP核壳型纳米复合材料,经磁分离固相萃取-高效液相色谱(MSPE-HPLC)技术,同时测定样品中3种四环素类抗生素的残留。用扫描电镜(SEM)、透射电镜(TEM)和红外色谱(FT-IR)对其表征。该方法对于四环素、土霉素、金霉素的检出限分别为9.61、7.84、11.93μg/kg,且在线性范围内线性关系良好。最大吸附量为56.28 mg/g。该方法的平均加标回收率在93.71%~100.88%之间,变异系数1.54%~7.44%。与非分子印迹聚合物相比,Fe3O4@Si O2@MIP分子印迹聚合物的吸附特异性较强。     

基于分子印迹整体柱的在线固相萃取-液相色谱联用测定奶粉中四环素类兽药残留

目的建立高交联结构的分子印迹整体柱(molecularly imprinted polymer monolithic column,MIP-MC)制备方法,利用在线固相萃取与液相色谱联用技术检测奶粉样品中四环素类兽药残留。方法在不锈钢色谱柱中,以土霉素为模板,甲基丙烯酸和甲基丙烯酸羟乙酯为功能单体,乙二醇二甲基丙烯酸酯和双季戊四醇六丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,在丙酮-甲醇-十二醇混合溶剂中,制备了分子印迹整体柱。将整体柱与液相色谱联用,在线固相萃取奶粉中的四环素类兽药残留。结果在最佳在线固相萃取条件下,获得了较高的富集因子(19.3)和净化效果。四环素类在0.05、0.25和0.5 mg/kg 3个加标水平下,回收率为84.2%~103.4%,相对标准偏差为1.37%~4.87%,方法检出限(S/N=3)和定量限(S/N=10)分别为8.48~11.74?g/kg和28.24~39.09?g/kg。结论该在线固相萃取方法简单快速、灵敏性高、选择性好,适用于奶粉中四环素类抗生素残留的测定。     

液相色谱-串联质谱法测定鸡蛋中的喹诺酮类和四环素类抗生素

应用液相色谱-串联质谱法技术,建立鸡肉中喹诺酮类和四环素类抗生素的检测方法,并对宁夏地区市售鸡蛋进行分析。鸡蛋样品经EDTA-Mcllvaine缓冲溶液超声提取,玻璃纤维滤膜过滤,HLB固相萃取柱净化,乙腈-0.1%甲酸水溶液为流动相,用Waters Atlantis T₃色谱柱分离,以电喷雾正离子模式进行质谱测定。三个加标水平下喹诺酮类抗生素回收率为80.0%~114.0%,相对标准偏差小于12.0%,检出限(S/N=3)为0.2 μg/kg,定量限(S/N=10)为0.8 μg/kg;四环素类抗生素的平均回收率为84.5%~110.0%,相对标准偏差小于12.0%,检出限(S/N=3)为0.2 μg/kg,定量限(S/N=10)为0.8 μg/kg。该方法操作快速简单、重现性好,可用于鸡蛋中喹诺酮类和四环素类抗生素的检测。     

高效液相色谱-串联质谱法测定能力验证肉粉中四环素类抗生素残留量

目的优化肉粉样品中四环素类药物的高效液相色谱-串联质谱检测方法。方法采用80%乙腈-水溶液提取肉粉样品中的四环素类药物,Prime HLB固相萃取小柱净化,洗脱液用氮气吹至近干,用10%乙腈水溶液(含0.2%甲酸)溶解,采用多反应监测正离子模式(multiple reaction monitoring, MRM)进行高效液相色谱-串联质谱仪测定。结果与国标方法GB/T 21317-2007(HLB固相小柱萃取法)相比,4种药物的线性范围均在5～200μg/L时线性良好(r 0.99),回收率差异不显著(P0.05)。实验室方法测得的含量分别为:四环素113.93μg/kg,金霉素68.16μg/kg,多西环素155.73μg/kg,土霉素未检出;回收率为四环素94.5%,金霉素95.2%,多西环素104.7%,土霉素97.8%。测得四环素、金霉素、多西环素、土霉素线性相关系数r分别为:0.9995、0.9998、0.9989、0.9997。结论本实验室方法简单快速,回收率高,重现性好,适用于熟肉制品中四环素类药物的多残留检测。     

超高效液相色谱-电喷雾串联质谱法同时测定生菜中四环素类抗生素及其代谢产物

目的建立超高效液相色谱-电喷雾串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)测定生菜中9种四环素类抗生素及其代谢产物的残留分析方法。方法生菜样品采用EDTA-Mcllvaine缓冲液与乙腈混合溶液提取,HLB固相萃取小柱净化,色谱分离选择ACQUITY UPLC BEH C18色谱柱,以乙腈和0.2%甲酸水溶液为流动相进行梯度洗脱,得到的分离效果较好。质谱采用电喷雾正离子电离、多反应监测模式检测。结果在0.01~0.5 mg/L范围内线性相关系数r2均大于0.99。仪器检出限为1.085~15.780μg/kg,方法的定量限为3.617~42.526μg/kg。在4个添加水平0.01、0.05、0.1和0.5 mg/kg下,除脱水四环素和差向脱水四环素(其回收率40%)外,其余四环素类抗生素及代谢产物在蔬菜中的添加回收率在为63.4%~101.3%,相对标准偏差为2.52%~12.56%。结论该方法灵敏度高,净化效果好,可以用于蔬菜中四环素类抗生素及其代谢产物的残留分析。     

高效液相色谱测定加工肉制品中四环素族抗生素的含量

建立一种采用高效液相色谱(HPLC)测定加工肉制品中四环素、土霉素和金霉素三种四环素族抗生素残留量的新方法。样品经体积分数0.5%的高氯酸溶液提取后,采用HLB固相萃取柱净化,用高效液相色谱C18柱分离,乙腈-甲醇-草酸作为流动相,流速为1.0 m L/min,梯度洗脱,紫外检测波长为275 nm,外标法峰面积定量。3种四环素质量浓度在10~100μg/L范围内均有较好的线性关系,回归系数R2均0.99,方法检出限为20μg/kg,回收率范围为93.5%~97.4%,相对标准偏差小于15%(n=8)。该法简单,灵敏度高,重复性好,适用于动物源性食品中四环素族组份残留的测定。     

高效液相色谱法和高效液相色谱-串联质谱法测定水产品中的四环素类残留量

目的 建立高效液相色谱法定量测定水产品中四环素类残留量,同时采用高效液相色谱-串联质谱法进行定性确证和定量检测。方法 具体优化了缓冲提取液浓度、固相萃取柱类型、色谱条件选择等测定环节。样品经柠檬酸缓冲液提取,固相萃取柱净化后,以液相色谱-紫外检测器进行定量检测,同时也可通过高效液相色谱-串联质谱仪进行定性和定量。结果 在10~200 ng/mL范围内线性良好(r>0.999),四环素类目标物在10、50、100 μg/kg 3个水平上进行加标回收试验,回收率为76.0%~94.5%,相对标准偏差为3.9%~7.4%,高效液相色谱法检出限为5 μg/kg,液相色谱-串联质谱法检出限为1 μg/kg。结论 该方法简便、稳定、准确,适合测定水产品中的四环素类残留量。     

特种黑鸡鸡肉四环素类药残检测及调查研究

针对四川乐山特种黑鸡鸡肉中四环素类兽药检测,得到采用Mcllivaine-Na_2EDTA缓冲溶液提取样品,Cleanert~PEP-2小柱净化;高效液相色谱法测定:色谱柱为Eclipse C_(18)(4.6 mm×100 mm,3.5μm);流动相:A相-甲醇,B相-0.01 mol/L草酸水溶液,C相-乙腈;柱温:40℃;进样量:100μL;检测波长:355 nm。方法标准曲线相关系数均大于0.995,四种抗生素最低检出限(LOD,S/N=3)分别为52,24,48和44μg/kg;定量限分别为84,80,88和84μg/kg。加标回收率均大于90%(加标浓度范围40~800μg/kg),RSD%均小于5%,方法准确可靠。以该方法调查养殖黑鸡四环素类抗生素残留,得到5个来自规模化养殖场黑鸡鸡肉样品四环素类兽药残留全低于100μg/kg限量[1];9个来自散养户的黑鸡样品,有6个样品1种四环素类兽药少量超限(超限量低于50%)。     

高效液相色谱串联质谱法同时测定9种龙虾中氨基糖苷类和四环素类抗生素残留

建立了龙虾中6种氨基糖苷类和3种四环素类抗生素残留的高效液相色谱串联质谱(HPLC-MS/MS)同时检测方法。样品中抗生素采用5%三氯乙酸-磷酸盐溶液提取,经超声萃取、固相萃取柱净化,C_(18)色谱柱分离,对样品前处理条件、液相色谱分离条件和质谱检测条件进行了优化。通过实际样品添加回收率实验,链霉素、双氢链霉素、四环素、金霉素和土霉素定量检出限均为5μg/kg,庆大霉素、卡那霉素、新霉素和妥布霉素定量检出限均为50μg/kg,9种抗生素三个添加水平下,龙虾样品加标回收率在66.1%~107.9%,相对标准偏差在0.7%~9.7%。结果表明,该方法准确、高效,适用于龙虾中6种氨基糖苷类和3种四环素类药物残留的同时检测和确证。     

固相萃取-超高效液相色谱串联质谱法测定牛奶中6种头孢菌素类抗生素

目的建立固相萃取超高效液相色谱串联质谱(SPE-UPLC-MS/MS)同时检测牛奶中6种头孢菌素类抗生素含量的方法。方法样品经0.05 mol/L的磷酸氢二钾缓冲溶液提取,HLB固相萃取柱净化,液相色谱串联质谱法测定,采用多反应监测模式进行定性和定量分析。结果 6种头孢菌素类抗生素的检出限(S/N=3)和定量限(S/N=10)范围分别为0.05~0.4μg/kg和0.1~1.6μg/kg。样品加标回收率范围为66.3%~110.0%。结论该方法便捷、快速、高效,能够满足牛奶中头孢菌素类抗生素的检测。     

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