气相色谱-质谱法测定食品中的3-乙酰基-2,5-二甲基噻吩

针对含油脂食品、不含油脂食品分别建立了有效的前处理方法,利用气相色谱-质谱技术,建立了一种简便高效、高灵敏度的检测食品中3-乙酰基-2,5-二甲基噻吩的定性定量分析方法。含油脂食品经甲醇提取后冷冻过滤、不含油脂食品经正己烷提取后离心,以气相色谱-质谱为检测手段,外标法定量。研究结果显示,3-乙酰基-2,5-二甲基噻吩在0.005μg/mL^1μg/mL浓度范围内曲线线性良好,相关系数为0.9999;在不同基质及不同加标浓度下,加标回收率为86.6%~104.6%,相对标准偏差(RSD_S,n=6)为0.9%~1.9%;3-乙酰基-2,5-二甲基噻吩在不同基质中的检出限均可达到0.01mg/kg,定量限达到0.03mg/kg。该方法前处理操作简便、技术难度低,准确度和灵敏度高,抗干扰能力强,定性定量准确并快速的测定出食品中3-乙酰基-2,5-二甲基噻吩的残留量。     

气相色谱-质谱法测定食品中 3-乙酰基-2,5-二甲基呋喃

目的 建立气相色谱-质谱法（gas chromatography mass spectrometry,GC-MS）测定食品中合成香料3-乙酰基-2, 5-二甲基呋喃的方法。方法 样品用正己烷涡旋提取后过滤,含油脂样品采用冷冻过滤技术去除油脂和其他杂质,选用TG-5MS毛细管色谱柱（30 m×0.25 mm,0.25 μm）,载气流速1 mL/min进行分离后进质谱分析。结果 3-乙酰基-2,5-二甲基呋喃在0.005~10 μg/L质量浓度范围内曲线线性良好,相关系数为0.9997;在不同基质及不同加标浓度下,加标回收率为80.79%~103.76%,相对标准偏差（n=6）为1.83%~7.87%;3-乙酰基-2, 5-二甲基呋喃在不同基质中的检出限均可达到1 μg/kg,定量限均可达到3 μg/kg。结论 该方法前处理方便快捷、准确度高、灵敏度好,可以用于食品中3-乙酰基-2, 5-二甲基呋喃含量的快速检测,为合成香料的安全使用和监管提供技术手段。     

气相色谱-质谱法测定食品中3-乙酰基-2,5-二甲基噻吩的含量

本文的目的是建立准确、高效的气相色谱-质谱法测定食品中3-乙酰基-2,5-二甲基噻吩含量的检测方法。样品经正庚烷超声萃取定容后,采用电子轰击电离源(EI)、选择离子监控(SIM)模式进行测定,外标法定量;对前处理中的萃取溶剂、萃取方法、萃取时间进行研究,并对检测方法进行方法学验证。根据不同空白基质的加标回收试验的结果显示,本方法前处理最优条件为使用正庚烷超声萃取15min。3-乙酰基-2,5-二甲基噻吩在0.1~2.0mg/L浓度范围内线性良好,相关系数R~2=0.997;在不同基质及不同加标浓度下,回收率为82.4%~100.8%,相对标准偏差为1.74%~3.90%。3-乙酰基-2,5-二甲基噻吩在不同基质中的检出限均可达到0.05mg/kg,定量限达到0.15mg/kg。故得出结论,本研究通过对前处理条件的研究和检测方法的方法学验证,建立了一种气相色谱-质谱法测定食品中3-乙酰基-2,5-二甲基噻吩含量的检测方法,该方法定性效果好、定量准确,且前处理操作简便、技术难度较低。     

气相色谱-质谱法测定食品基质中四聚乙醛残留量

建立气相色谱-质谱法测定食品基质中四聚乙醛残留量。采用二氯甲烷-丙酮混合溶剂提取,石墨化炭黑/氨基复合固相萃取柱净化,气相色谱-质谱法检测大米、大豆、菠菜、番茄、洋葱、茶叶、苹果、板栗等多种植物源食品基质中四聚乙醛残留的方法。结果表明,该方法定量限为0.01mg/kg,在添加0.01～0.5mg/kg范围内,加标回收率为70.5%～111.7%,相对标准偏差为4.4%～11%。     

微波辅助净化-气相色谱法测定含硫蔬菜中有机磷农药残留

目的 建立微波辅助净化-气相色谱法测定含硫蔬菜中有机磷农药残留的分析方法。方法 样品经微波预处理抑制酶促反应后, 使用乙腈提取、基质分散固相萃取净化、丙酮复溶、有机滤膜过滤后, 采用气相色谱-火焰光度检测器测定。结果 敌敌畏、甲胺磷、氧乐果、乐果、毒死蜱、水胺硫磷在0.01~0.50 μg/mL浓度范围内呈现良好的线性关系, 相关系数均大于0.999, 方法的检出限为0.0002~0.0004 mg/kg, 定量限为0.0008~0.0013 mg/kg; 有机磷农药在香葱、韭菜、白萝卜基质中加标0.002, 0.010, 0.100 mg/kg 浓度水平, 加标回收率为83.2%~104.7%, 相对标准偏差在2.3%~10.2% (n=6)。结论 本方法简便, 抗干扰能力强, 定量准确, 具有良好的重现性和稳定性, 能够有效的检测含硫蔬菜中有机磷农残的含量。     

固相萃取-气质联用法测定食品中富马酸二甲酯

建立一种测定不同食品中富马酸二甲酯含量的快速气相色谱-质谱(GC-MS)方法.不同基质的样品(含脂肪、脂肪酸、色素等干扰物)加入有机溶剂经超声波提取后,采用固相萃取净化,然后经GC-MS定性、定量测定.结果表明,采用乙腈作为提取溶剂所得样品净化完全,无杂质干扰,定量准确.方法的检出限(信噪比S/N=3)为0.020 mg/kg,定量限(信噪比S/N=10)为0.067 mg/kg,不同食品中富马酸二甲酯加标回收率范围为93.9 ％～104.3％,相对标准偏差(RSD)小于1.86％,该方法满足不同食品中富马酸二甲酯检测要求.     

Carrez试剂沉淀-气相色谱法测定复杂基质食品月饼中的甜蜜素

建立了应用Carrez试剂沉淀、亚硝酸酯化和气相色谱、氢火焰离子化检测器测定复杂基质食品月饼中甜蜜素的方法.考察了不同提取方式(高速匀浆、超声和研磨)的提取效率和Carrez试剂用量对甜蜜素测定的影响.试样经高速匀浆提取、Carrez试剂沉淀分离杂质后,在硫酸介质中经亚硝酸酯化,衍生物经气相色谱分离、氢火焰离子化检测器测定.方法的检出限为2mg/kg(S/N=3).在添标水平为0.25、0.50和1.0 mg/g时的平均添加回收率为85.12%～99.38%,相对标准偏差6.44%～8.31%.衍生物的峰面积与样品浓度在0.125～1.0g/L范围内呈良好的线性关系,相关系数为0.9992.该方法仪器设备简单,测定结果准确、可靠,适合复杂基质食品中甜蜜素的测定.     

分散固相萃取-液相色谱-串联质谱法测定植源性油料油脂中67种除草剂

目的 建立分散固相萃取结合液相色谱-串联质谱同时测定油料油脂中 67 种除草剂残留的检测方法。方法 选取花生、大豆、油菜籽、花生油、大豆油及菜籽油为典型基质试样,经 1% 甲酸-乙腈提取,通过乙二胺基-N-丙基和无水 MgSO₄分散固相萃取净化。以甲醇和 5 mmol/L 乙酸铵(含 0. 1% 甲酸)为流动相梯度洗脱,采用 C₁₈色谱柱分离,ESI 离子源正负离子模式同时进行多反应监测(MRM),基质标准曲线外标法定量。结果 基质加标试验结果表明,0. 000 5～0. 08 mg/L 浓度范围内 67 种除草剂线性良好,决定系数(R²)均>0. 992,定量限(LOD)为 0. 005～0. 02 mg/kg。3 个加标水平下(LOD、2LOD、10LOD)的回收率为 62. 3%～118. 1%,RSD(n=6)均<15%。结论 本方法稳定性高、特异性强、灵敏、准确、高效,可以用于油料油脂中多种除草剂残留的定性定量检测。     

气相色谱-氮磷检测器法测定小麦粉及其制品与小麦粉添加剂中的乙酰氧肟酸

建立了气相色谱-氮磷检测器法测定小麦粉及其制品与小麦粉添加剂中非法添加物乙酰氧肟酸(AHA)的分析方法。以小麦粉、小麦粉添加剂、面皮、面条、馒头为研究基质,优化了色谱条件,并通过向5种空白基质进行加标回收实验优化前处理方法。样品经无水乙醇超声和涡旋振荡提取,高速离心、过滤,采用DB-WAX(60 m×0.32 mm, 0.25μm)色谱柱分离,外标法定量。结果表明：AHA溶剂和基质标准曲线在0.60～10.00μg/mL范围内线性关系良好,相关系数均大于0.998,检出限为2 mg/kg,定量限为6 mg/kg;加标回收率为86.19%～109.22%,相对标准偏差(n=6)为1.47%～7.89%。方法适用于小麦粉及其制品与小麦粉添加剂中AHA的测定。     

气相色谱-三重四极杆串联质谱法测定肉制品中7种己二酸酯类物质残留

目的 建立气相色谱-三重四极杆串联质谱法同时测定7种己二酸酯类物质残留量的分析方法,并对肉制品中7种己二酸酯类物质进行筛查。方法 样品经乙腈提取,提取液用Sin Ch ERS-General柱净化,多反应监测模式进行检测,基质匹配曲线外标法定量。结果 采用基质匹配标准曲线定量的方法降低了基质效应,满足定量分析要求。该方法线性关系良好, 7种己二酸酯类物质的线性范围为0.01～0.40 mg/L,相关系数(r2)均大于0.999。在0.04、0.10、0.20mg/kg3个不同加标浓度水平下,7种己二酸酯类物质的回收率为73.5%～117.5%,相对标准偏差(relative standard deviations, RSDs)为0.8%～8.2%。方法检出限为0.01 mg/kg,方法定量限为0.03 mg/kg。对59份肉制品中的7种己二酸酯类物质含量进行检测分析,结果显示,有6份样品检出,其中己二酸二(2-乙基己基)酯的检出浓度为0.071～5.930 mg/kg,双(1-丁基戊基)己二酸酯的检出浓度为0.056～0.480 mg/kg,其他己二酸酯类物质均未检出。结论 该方法前处...     

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