气相色谱-质谱/选择离子监测法分析烟草中的重要香味物质

采用优化的同时蒸馏萃取前处理方法,以乙酸苯乙酯为内标,对烟草中的致香物质进行了气相色谱-质谱/选择离子监测(GC-MS/SIM)分析,准确测定了卷烟中的吡啶、噻唑、吡咯等24种碱性香味成分和糠醛、糠醇、β-紫罗兰酮等34种中性香味成分。结果表明:中性香味成分的回收率为73.05%~97.35%,相对标准偏差(RSD)小于10%,其中20种成分的回收率高于80%;碱性香味成分的回收率为71.49%~98.93%,其中22种成分的RSD小于10%,2-甲基吡嗪和四甲基吡嗪的RSD分别为14.96%和11.81%。     

加料前后烟草中游离及糖苷结合态香味成分的分析研究

对加料前后烟草中游离及糖苷结合态香味成分进行了分析研究。烟末经乙醚萃取和同时蒸馏萃取(SDE)分离得游离香味成分。糖苷成分用甲醇萃取,采用非离子型大孔树脂(AB8,相当于AmberliteXAD-2)吸附,然后用不同选择性溶剂洗脱和溶剂萃取,使糖苷与可溶性糖、氨基酸、有机酸、游离香味成分分离。糖苷集份在弱酸条件下(pH2.5)SDE水解,同时萃取出精苷结合态香味成分。采用毛细管气相色谱(HRcGC)和气相色谱/质谱联用(GC/MS)技术鉴定了25种游离及糖苷结合态香味成分。对加料前后的烟草样品进行了对比分析,结果发现:在所分析的烟草样品中,糠醇、苯乙醇、茄酮、香叶基丙酮、β-紫罗兰酮等成分,游离态含量高于结合态的含量;苯酚、香草醛、巨豆三烯酮等成分,游离态和结合态的含量相当;糠醛、苯甲醛、苯乙酮、异佛尔酮、氧化异佛尔酮、4-乙烯基愈创木酚、大马酮、二氢大马酮等成分,结合态的含量高于游离态含量。加料前后的烟草样品相比,加料后烟草中游离态香味成分呈减少趋势,但结合态含量呈增加趋势。      

微波萃取-GC/MS/MS测定抗菌织物的三氯生含量

以二氯甲烷为萃取溶剂,采用微波辅助萃取技术萃取抗菌织物中的抗菌剂三氯生;萃取液经衍生化处理后进行气相色谱/串联质谱(GC/MS/MS)分析,从而建立了一种测定抗菌织物中三氯生的气相色谱/串联质谱方法.该方法灵敏度高,检出限为0.3 ng/mL( S/N= 10),平均回收率为99.1％～101.2％,精密度为3.0％ ～7.1％.     

β-紫罗兰醇葡糖苷热裂解产物及其在卷烟主流烟气中的释放行为

为了掌握β-紫罗兰醇葡糖苷在卷烟主流烟气中的释放情况,对所合成的β-紫罗兰醇葡糖苷进行了热裂解-气相色谱/质谱(Py-GC/MS)分析,并采用GC/MS考察了裂解产物中香味成分在卷烟主流烟气中的释放情况.结果表明:①β-紫罗兰醇葡糖苷热裂解能生成多种香味成分;②在卷烟燃烧过程中能够有效释放出β-紫罗兰醇、β-紫罗兰酮和巨豆三烯,同时巨豆三烯酮释放量也呈增大趋势;随着添加量的增大,特征香味成分的释放量随之增大;③裂解产物在卷烟主流烟气中的释放具有良好的稳定性和均匀性.     

GC/MS、GC×GC/TOFMS分析烟草半挥发性中性成分比较

为比较气相色谱质谱(GC/MS)与全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)在定性定量方面的差别,考察了色谱柱系统、操作条件(调制周期、柱头压力和初始温度等)对两维分离的影响,建立了烟草半挥发性中性化学成分分析的GC×GC/TOFMS方法,并采用这2种方法分析了云烟85的C3F烟叶的半挥发性中性成分。结果显示①GC/MS法共分离出400多个峰,鉴定出73种成分,而GC×GC/TOFMS法分离出近万个峰,共鉴定出569种成分;②在一维GC中峰形很好的β-大马酮的色谱峰,在GC×GC中经调制后被分离成6种成分1-氧化乙烯基癸烷、1-甲基-4-(2-甲基环氧乙烷基)-7-氧-二环[4,1,0]庚烷、二联苯、β-大马酮、10-乙酰甲基-3-蒈烯和正十四烷。因此,GC×GC/TOFMS分离能力更强,定性定量结果更可靠,更适合复杂体系的分离分析。     

基质固相分散-气相色谱-串联质谱法测定焙烤食品中氨基甲酸乙酯

建立了焙烤食品中氨基甲酸乙酯的基质固相分散-气相色谱-串联质谱联用(MSPD-GC/MS/MS)的测定方法,样品经硅藻土吸附后转入层析柱中进行基质固相分散萃取,用正己烷洗脱非极性成分,再用二氯甲烷洗脱目标物,采用DB-225MS毛细管柱分离样品,气相色谱-串联质谱法测定氨基甲酸乙酯的含量。结果表明,该方法标准曲线线性良好,线性范围为5～500μg/L,相关系数r=0.9997,方法检出限2.5μg/kg,标准加入5～100μg/kg的平均回收率为95.40%～98.00%。该方法具有操作简便、可靠、灵敏度高、定量准确等优点,可用于焙烤食品中的氨基甲酸乙酯检测。     

顶空固相微萃取-气相色谱-质谱测定百香果香气条件的优化

对使用固相微萃取-气相色谱-质谱联用仪分析百香果香气成分的关键因素进行了讨论,分析各因素对不同相对分子质量化合物萃取效果的影响.通过优化,获得最佳萃取条件,即:5 mL果汁中加入3 g氯化钠,使用50/30μm的DVB/CAR/PDMS纤维头50℃下萃取20 min.将最佳条件下所得谱图与标准谱图比对,共鉴定出39种化合物,占峰面积总和的92.52%,表明采用固相微萃取-气相色谱-质谱联用仪可对百香果主要香气成分进行快速、准确地定性与定量分析.     

四氮杂杯[2]芳烃[2]三嗪键合硅胶固相萃取/HPLC-MS/MS法测定家兔血浆中的TSNAs

为了准确测定家兔血浆中的烟草特有N-亚硝胺(TSNAs),制备了四氮杂杯[2]芳烃[2]三嗪键合硅胶(NCS)固相萃取柱,并通过对NCS固相萃取、色谱及质谱条件的优化,建立了测定家兔血浆中的N-亚硝基降烟碱(NNN)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇(NNAL)、N-亚硝基新烟草碱(NAT)和N-亚硝基假木贼碱(NAB)5种TSNAs的NCS固相萃取/HPLC-MS/MS方法.结果表明:NCS固相萃取柱对家兔血浆中5种TSNAs的萃取效率优于商品化的C18固相萃取柱;5种TSNAs的检测限为0.0092～0.0590 ng/mL,回收率和相对标准偏差(RSD)分别为90.1％～113.3％和0.95％～7.22％.该方法简单、准确,适合于家兔血浆中TSNAs的检测.     

姜油树脂中主要活性成分的GC/MS检测条件研究

针对姜油树脂中烯类和酚类物质的特点,调整气相色谱-质谱联用方法的测试条件,获得了适于超临界CO2萃取的姜油树脂成分分析的GC/MS测试方法.在选定的检测条件下,可分析姜油树脂中主要的活性成分,检出物30多种.其中烯类主要成分α-姜黄烯(3.69％)、姜烯(17.11％)、α-法尼烯(2.28％)、β-没药烯(5.12％)和β-倍半水芹烯(7.77％)等倍半萜类化合物的分离效果好.姜辣素类的主要物质姜酚(7.70％)在检测过程中受热部分分解形成姜酮(30.36％)等热解产物,因此须同时计量分解和未分解部分.     

云晓养生保健醋香味成分的GC-MS分析

采用同时蒸馏萃取(SDE)提取云晓养生保健醋的挥发性香味物质,利用气相色谱-质谱联用仪(GC-MS)对其挥发性香味成分进行分离和鉴定,确认了其中的43种成分,占总质量分数的98.371%.并用面积归一化法测定了各种成分的质量分数,其主要成分为醋酸(45.591%)、3-羟基丁酮(24.408%)、糠醛(21.522%)、吡嗪类物质(1.072%)、乳酸乙酯(1.031%)和β-苯乙醇(0.473%)等.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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