微波消解-原子荧光光谱法测定云南食用玫瑰中重金属元素

建立基于微波消解和原子荧光光谱法测定云南食用玫瑰中重金属含量的方法,考察并优化微波消解和仪器测定条件,对云南某市食用玫瑰中重金属As、Pb、Hg含量进行测定。结果表明:As、Pb、Hg元素的浓度分别在1.0μg/L～100μg/L、1.0μg/L～80μg/L、0.4μg/L～10μg/L之间呈良好线性关系,检出限分别为0.005 3、0.022 7、0.007 9μg/L,加标回收率可达90.2%～107.5%,相对标准偏差(relative standard deviate,RSD)5.0%。云南某市6个村食用玫瑰重金属As、Pb、Hg的含量分别为0.016 mg/kg～0.113 mg/kg、0.225 mg/kg～0.308 mg/kg、0.000 2 mg/kg～0.001 2 mg/kg之间,同食品安全国家标准对照,发现食用玫瑰中Pb含量存在超标情况。     

自动石墨消解-电感耦合等离子体质谱法监测干制水产品中的铅、砷、铝、铬、铁、铜

为建立同时检测干制水产品中铅、砷、铝、铬、铁、铜金属残留的电感耦合等离子体质谱(Inductively coupled plasma mass spectrometry,ICP-MS)方法。选择自动石墨消解仪对样品进行消解,消解完全后,利用ICP-MS对样液进行检测,内标法定量分析。结果显示:铅、砷、铝、铬、铁、铜元素浓度在0. 25～25μg/L范围内线性良好,相关系数(R2)均大于0. 990;检测限:铅0. 02μg/L、砷0. 08μg/L、铝0. 12μg/L、铬0. 10μg/L、铁0. 03μg/L、铜0. 05μg/L;加标回收率在84. 0%～108. 4%之间;方法重复性RSD(n=6)低于10%。该方法操作简单、准确度高、检测限低、重复性好,可以用于干制水产品中的金属元素检测。     

LC-ESI-MS/MS测定白酒中7种甜味剂的方法研究

建立使用液相色谱-质谱联用仪测定白酒中7种甜味剂含量的分析方法。分析条件:分析柱为Agilent ZORBAX RX-C18,流动相为0.02 mol/L乙酸铵水溶液+0.1%乙酸溶液和甲醇溶液采用梯度洗脱。结果表明,该方法在14 min内完成,安赛蜜、糖精钠、甜蜜素和阿力甜在10～200μg/L的范围内线性关系良好(相关系数r=0.999),检出限是10μg/L、定量限是20μg/L;阿斯巴甜、纽甜在50～1000μg/L的范围内线性关系良好(相关系数r=0.999),检出限是50μg/L、定量限是100μg/L;三氯蔗糖在40～800μg/L的范围内线性关系良好(相关系数r=0.999),检出限是40μg/L、定量限是80μg/L。样品中添加不同浓度的甜味剂时,回收率均在85%～105%范围内,相对偏差小于2%(n=12)。该方法样品处理简单,其线性范围内、相关性、灵敏度和精密度均符合白酒中甜味剂检测方法的要求。     

流动注射法在线同时测定水中硝酸盐氮和亚硝酸盐氮

将镀铜镉柱应用于流动注射(FIA),通过三通阀自动控制,实现了水中硝酸盐氮和亚硝酸盐氮的同时测定。在盐酸介质中,亚硝酸盐与磺胺发生重氮化,然后与N-(1-萘基)-乙二胺盐酸盐相偶合,形成玫瑰红色的偶氮染料,在530nm处有较大吸收,硝酸盐被镉柱在线还原为亚硝酸盐后同法测定。硝酸盐和亚硝酸盐的测定范围分别为2～50μg/L、20～1000μg/L,检出限分别为0.33μg/L和0.66μg/L,精密度RSD为0.73%和1.48%,测定频率为16样/h。实际水样中硝酸盐和亚硝酸盐的测定取得了满意的效果,加标回收率均在95.3%～111.0%之间。该方法简单、快速、重现性好,可应用于实际检测。     

液相色谱-串联质谱联用法测定酱油中T-2毒素残留

目的:研究以液相色谱-串联质谱联用法测定酱油中T-2毒素含量的方法。方法:液相色谱-串联质谱法。用乙腈-0.1%甲酸溶液提取酱油,经C18净化,电喷雾正离子多反应监测(MRM)模式检测。结果:T-2毒素在1～25μg/L的系列浓度范围呈线性相关,酱油中T-2毒素的检测限为2.0μg/kg,定量限为5.0μg/kg,在2～20μg/kg的添加浓度范围内平均回收率为85.5%～98.2%。结论:该方法灵敏度高,重现性好,可作为酱油中T-2毒素残留量检测方法。     

反相高效液相色谱法对猪肉组织中恩诺沙星和环丙沙星残留量检测的改进

利用配有荧光检测器的高效液相色谱同时分析动物组织中恩诺沙星及其代谢产物环丙沙星的含量.研究结果表明:环丙沙星、恩诺沙星的质量浓度在2μg/L～100μg/L范围内呈线性关系,相关系数分别为0.9993和0.9991,该方法中恩诺沙星和环丙沙星的最低定量限均为2μg/Kg(S/N=10),恩诺沙星的回收率为85%～90%,环丙沙星的回收率为92%～99%.     

微流控芯片联用高效液相色谱-荧光检测器同时测定肉类食品中4种磺胺类药物残留

目的 建立一种使用微流控芯片进行肉类食品前处理,并结合高效液相色谱-荧光检测器(high performance liquid chromatography-fluorescence detector, HPLC-FLD)同时测定肉类食品中4种磺胺残留的方法。方法 样品先用乙酸乙酯提取后,在微流控芯片中用2 mol/L盐酸溶液反萃取和正己烷脱脂,收集盐酸流出液100μL,与0.5 g/mL醋酸钠溶液按照1:1(V:V)混合,加入0.2 g/L荧光胺50μL进行衍生化反应,采用岛津ODS-3色谱柱进行分离,流动相为乙腈-2%乙酸水溶液。结果 4种磺胺完全分离且在0.01～1.00mg/L呈良好的线性关系,在50、100、200μg/kg3个添加水平下,平均回收率为72.1%～91.6%,相对标准偏差为4.7%～13.6%,方法检出限为1～5μg/kg。结论 该方法具有快速、方便、经济、除脂效果好、环保等优点,适合肉类食品中4种磺胺类药物残留分析,并且提供了一个新的样品前处理思路。     

生鲜牛乳中莱克多巴胺的测定

在生鲜牛乳中莱克多巴胺的检测限为2μg/kg,本方法在2μg/kg～10μg/kg添加浓度水平上回收率为60%～120%,本方法与仪器技术分析相比具有操作简便、快速、准确度和灵敏度高,样品加标率回收效果好、检出限低、试剂盒稳定性好、重现性好等特点。     

石墨炉原子吸收测定生态纺织品中可萃取痕量镉

纺织品萃取汗液中的痕量镉是生态纺织品的重点限制项目。文章采用石墨炉原子吸收光谱法(GFAAS)直接测定生态纺织品萃取汗液中的痕量镉,对NH4H2PO4、NH4NO3、Pd(NO3)2、Mg(NO3)2的单个或混合基体改进剂进行筛选,并对基体改进剂用量及石墨炉工作条件进行优化试验。结果表明,加入7μL的50g/LNH4NO3与10g/LNH4H2PO4(V:V=1:1)混合基体改进剂,可以有效地降低背景信号,消除基体干扰,提高测量的灵敏度。镉浓度在0.5μg/L～5.0μg/L时,线性关系良好,精密度为1.79%～3.89%,方法检出限为0.05μg/L,加标回收率为87.5%～104.5%。     

超高效液相色谱-高分辨质谱法测定牛奶中7种有机磷酸酯类阻燃剂

目的 建立牛奶中7种有机磷酸酯类(OPEs)阻燃剂的超高效液相色谱-高分辨质谱分析方法。方法 基于乙腈-冷冻诱导液液萃取技术提取、净化和富集样品,以甲醇-水作为流动相,梯度洗脱程序,HSS T3色谱柱(2.1 mm×100 mm,1.8μm)分离,高分辨质谱靶向单一离子监测模式测定,内标法定量。结果 7种OPEs在0.2～20μg/L范围内呈良好的线性关系(R²>0.99),方法检出限为0.01～0.21μg/L,定量限为0.04～1.72μg/L,3个不同加标水平的回收率为88.4%～118%,相对标准偏差为1.15%～7.15%。结论 该方法操作简便,重复性好,灵敏度高,可应用于牛奶中OPEs的痕量检测。     

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