高温GC-MS联用技术在油脂分析中应用

国内对油脂分析,主要是采用气相色谱分离和火焰离子化检测器(FID)检测其中脂肪酸 组成,而对甘油酯分离和检测报道较少;近年来国外许多研究者利用高温气相色谱和质谱联用 (HTGC-MS)等技术对甘油三酯分离和检测进行大量研究。该文对利用HTGC-MS分离和检测 油脂中甘油三酯研究进行综述。     

超临界流体色谱和质谱联用在油脂分析中的应用

对油脂的分析,国内主要是采用气相色谱分离和火焰离子化检测器(FID)检测其中的脂肪酸组成,而对甘油酯的分离和检测报道较少,国外研究者利用色谱和质谱联用技术对甘油三酯的分离和检测做了大量的研究。超临界流体色谱是新近发展起来的分离技术,它保留了气相色谱和液相色谱的优点,但在一些方面更有优势。对超临界流体色谱的分离技术进行了介绍,并对超临界流体色谱和质谱联用(SFC-MS)技术在甘油三酯的分离和检测方面的应用和研究进展进行了综述。超临界流体色谱和质谱联用技术将是未来甘油三酯分离和检测的最佳方法。     

顶空固相微萃取- 气相色谱/质谱法分析霸王花挥发性成分

目的：探索分析霸王花挥发油化学成分的方法。方法：采用聚二甲基硅氧烷萃取头室温顶空微萃取20min、初始柱温60℃、程序升温至250℃、进样口温度250℃的气相色谱条件,EI 离子源、电子能量70eV 的质谱条件进行气相色谱/ 质谱法分析。结果表明：共鉴定出49 种化合物,主要挥发性成分及其含量为倍半萜及其含氧衍生物(27.78%)、脂肪族化合物(25.14%)、酯(14.40%)、2,6- 二叔丁基对甲酚(10.08%)和硅氧烷类化合物(6.27%)。结论：无溶剂的顶空萃取- 气相色谱/ 质谱联用技术可作为霸王花挥发性成分分析的有效方法。     

食用油中甘油三酯聚合物含量测定

氧化甘油三酯和甘油三酯聚合物含量同油脂氧化程度相关联,结合极性组分分离技术和高效体积排阻色谱技术,建立了食用油中甘油三酯聚合物含量测定方法,对天津市常见42种食用油中氧化甘油三酯和甘油三酯聚合物含量进行了测定,结果显示虽然甘油三酯聚合物平均含量接近(1.43%~1.85%),但不同类食用油中甘油三酯二聚物与寡聚物含量比相差较大,以此为基础通过进一步优化方法和扩大样品数据量,所建立的深度氧化劣质食用油鉴别方法,将具有良好的应用前景。     

烟叶热裂解产物的分析研究

为研究烟叶热裂解行为对卷烟烟气成分的影响,采用在线热裂解-气相色谱/质谱联用技术(Py-GC/MS)分析烟叶在氦气氛围中不同温度(300℃,600℃和900℃)下的热裂解产物.将热解产物直接引入气相色谱-质谱仪,用质谱法对裂解产物进行了定性分析,并用面积归一法定量分析.结果表明:300℃,600℃和900℃下的热裂解产物中分别鉴定出45种、110种和124种裂解产物;裂解温度对烟叶产生的裂解产物种类和相对含量都有较大影响,裂解出的致香成分包括酮类、醇类、醛类、酯和内酯类、酸类和氮杂环类等,其相对含量在裂解温度为600℃时达到最大.     

液相色谱在食用油中甘油三酯分析检测中的应用

甘油三酯是食用油的主要组成部分,是人体热量和必需脂肪酸的重要来源。甘油三酯的成分性质不仅会影响食用油脂的理化,也影响其营养价值。基于食用油脂中甘油三酯种类的复杂性,甘油三酯的检测面临巨大的挑战。介绍近几年非水反相液相色谱和银离子液相色谱在甘油三酯检测上的应用。     

文王贡“绵甜型”白酒香气成分分析

以普通浓香型白酒为对照,分别采用气相色谱(GC)直接进样与气相色谱-质谱联用技术(GC-MS)对文王贡"绵甜型"白酒进行定量分析与定性分析。分析结果表明,文王贡"绵甜型"白酒符合浓香型白酒的特征,但又区别于普通浓香型白酒,两者在香气成分含量及各香气成分之间的比例不同,且文王贡"绵甜型"所含高沸点物质较少。     

毛细管气相色谱法分离高效氯氰菊酯异构体

采用DB-1石英毛细管柱(60 m×0.25 mm×0.25μm),ECD电子捕获检测器,在程序升温,进样口温度260℃,检测器温度300℃,不分流进样的条件下,建立了高效氯氰菊酯4个立体异构体的气相色谱分离方法,该分析方法简便、快速、重现性好,分析结果准确、可靠。     

凝胶渗透色谱-气相色谱-质谱法测定食用油中8种邻苯二甲酸酯类增塑剂

建立了凝胶渗透色谱-气相色谱-质谱法测定食用油中8种邻苯二甲酸酯类增塑剂的方法。采用凝胶渗透色谱(GPC)对食用油样品进行二次净化后进行气相色谱-质谱分析。结果表明:该方法的检出限在0.10~0.46μg/kg,定量限为0.35~1.52μg/kg,在2.38~9.52 mg/L范围内呈现良好的线性关系(R~20.99),加标回收率为89%~101%,相对标准偏差(RSD)在2.1%~7.7%之间。该方法可满足食用油中邻苯二甲酸酯类增塑剂的检测要求。     

特丁基对苯二酚(TBHQ)应用与检测

本文综述特丁基对苯二酚(TBHQ)应用与检测。TBHQ对大豆油、鱼油等食用油具有良好抗氧化作用,在油中其抗氧化能力优于叔丁基对羟基茴香醚、2,6-二叔丁基对甲苯和没食子酸丙酯。柠檬酸对TBHQ抗氧化作用具有一定增效作用。在高温环境中(如160℃),TBHQ抗氧化效果不好,要使用微胶囊抗氧剂才能获得较好效果。可采用气相色谱配氢火焰离子化检测器和液相色谱配紫外检测器定量分析TBHQ。     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.