纺织品中小分子醛的液相色谱串联质谱法测定

建立了纺织品中微量甲醛、乙醛、丙醛、丁醛和戊醛的高效液相色谱串联质谱测定方法.以2.0％磷酸为溶剂,以超声波辅助技术进行萃取,采用2,4-二硝基苯肼(DNPH)衍生,衍生物在BEH C18色谱柱(75 mm×2.0 mm,2.2μm)上以甲醇-0.05％甲酸为流动相,采用梯度洗脱分离,电喷雾电离(ESI)正离子多反应监...     

基于2种衍生化方法对牛乳中寡糖的高效液相色谱-质谱联用分析

利用Sep-Pak C_(18)柱和石墨化碳柱对已脱脂和除去蛋白质的牛乳进行分离纯化,并采用1-苯基-3-甲基-5-唑啉酮(3-methyl-1-phenyl-2-pyrazolin-5-one,PMP)和2-氨基吖啶酮(2-aminoacridone,AMAC),2种衍生化试剂对其进行衍生化处理,通过高效液相色谱进行优化,AMAC衍生化的结果(约有67个峰)明显优于PMP衍生化的结果(约20个峰),最终确定AMAC为最佳衍生化试剂,并利用最终优化好的高效液相色谱条件,采用高效液相色谱-串联离子阱飞行时间质谱对牛乳中寡糖进行测定,最终测得7种乳寡糖并获得该7种乳寡糖的单糖组成。     

基于UPLC-Orbitrap-HRMS技术的苎麻籽乙醇提取物中主要化学成分分析与鉴定

应用超高效液相色谱-离子阱-超高分辨率质谱技术对苎麻籽乙醇提取物主要化学成分进行了分析与鉴定.高效液相色谱条件为Agilent 5TC-C18色谱柱(4.6 mm×250 mm,5μm)、0.2％甲酸水溶液-乙腈作为流动相梯度洗脱.质谱条件为电喷雾离子源(ESI),离子阱质量分析器(orbitrap),喷雾电压3500...     

花蛤中糖胺聚糖的分离与结构鉴定

目的:以花蛤为提取原料,用多酶水解法提取花蛤中糖胺聚糖,利用红外光谱法对提取物中的硫酸软骨素的结构进行分析。采用超高效液相色谱与电喷雾-质谱联用技术对糖胺聚糖类组分进行研究。方法:色谱柱ACQUITY UPLC BEH Amide(2.1 mm×100 mm,1.7μm);保护柱ACQUITY UPLC BEH Amide Van Guard(2.1 mm×5 mm,1.7μm);流动相乙腈-水(体积分数0.2%冰醋酸)的体积比为75∶25;流速0.1 m L/min;进样20μL。结果:超高效液相色谱-电喷雾-质谱法可快速定性分离糖胺聚糖组分。结论:本实验为糖胺聚糖化合物的结构鉴定提供了一种有效的分析方法。     

高效液相色谱-电喷雾质谱法测定浒苔中的叶黄素

建立反相高效液相色谱- 电喷雾电离质谱法(RP-HPLC-DAD-ESI-MS)定性、定量测定绿潮藻浒苔中叶黄素的新方法。浒苔样品经超声辅助提取后,采用RP-HPLC-DAD-ESI-MS 联用技术对其进行分离鉴定,HPLC 采用Eclipse XDB-C18(150mm × 4.6mm,5μm)色谱柱,以含0.2% 乙酸的甲醇溶液- 水为流动相,线性梯度洗脱,检测波长450nm。在选定的最佳仪器条件下,叶黄素与浒苔中的其他化合物分离良好,叶黄素在0.10～20.0mg/L 质量浓度范围内具有良好的线性关系(R2=0.9994),能对浒苔提取液中的叶黄素进行准确定量;采用电喷雾质谱联用分析能快速获得叶黄素的分子量信息,可为浒苔中叶黄素的快速鉴别提供依据。     

HPLC-DAD-ESI-MS技术分离鉴定啤酒中异α-酸顺/反异构体

建立了1种采用高效液相法测定啤酒中异α-酸顺/反异构体的方法。样品通过异辛烷液液萃取获得,然后使用Purospher STAR RP_(18)(4.6 mm×250 mm,5μm)色谱柱,在甲醇-乙酸铵缓冲液作为流动相条件下等梯度分离,分离在50 min内完成。依据ESI-MS的选择性,使用高效液相色谱-二极管阵列检测器-电喷雾质谱联用(HPLC-DAD-ESI-MS)操作区分各化合物。根据保留时间、UV和MS图谱鉴定各目的蜂。该方法准确可靠,最低检测限0.21 mg/L。     

UPLC和Q-Exactive高分辨质谱仪联用鉴定大黄鱼中的甘油三酯分子组成

应用超高效液相色谱和电喷雾/四极杆-静电场轨道阱的质谱联用技术,分析大黄鱼脂肪中甘油三酯的组成。采用Hypersil Gold C_(18)柱(150mm×4.6mm,2.1μm),流动相为82%甲醇(含0.1%甲酸)溶液和18%异丙醇溶液,混合后添加0.05%乙酸铵溶液,以等度洗脱方式分离大黄鱼脂肪中的甘油三酯组分,柱后流出液采用电喷雾离子源,以正离子模式采集一级质谱分子离子和二级质谱的碎片离子信息,然后与Lipidblast数据库中甘油三酯信息进行比对。研究结果显示,超高效液相色谱和Q-Exactive高分辨质谱仪联用技术快速、准确鉴定出大黄鱼脂质中含有28种甘油三酯。PoOL、Po SO、PPO、PPoO、PSO、MPO、POL、PoSA8种甘油三酯占总量的87.87%以上,其中PoOL(C_(16:1)、C_(18:1)、C_(18:2))相对含量最丰富,占35.261%。     

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<正>高效液相色谱-四极杆/离子阱质谱确证测定面粉及面制品中氨基脲采用高效液相色谱-四极杆/离子阱质谱(HPLC-QTRAP-MS)建立了面粉及面制品中氨基脲的确证及测定方法。样品采用盐酸(HCl)提取,在超声辅助下与衍生剂邻硝基苯甲醛反应。衍生产物在中性条件下经PLS固相萃取柱净化、乙酸乙酯洗脱,经Shim-Pack XR-ODSⅢC18柱(2.0 mm×50 mm,     

β-环糊精与麦芽糊精对扇贝粉风味物质及氨基酸含量的影响

为开发优质扇贝粉,研究了β-环糊精与麦芽糊精对扇贝粉风味物质及氨基酸(amino acid,AA)含量的影响.采用顶空固相微萃取(HS-SPME)与气相色谱-质谱联用(GC-MS)技术,鉴定了不加β-环糊精与麦芽糊精(处理1)和添加β-环糊精与麦芽糊精(比例为1:8)(处理2)的2种扇贝粉风味物质,采用高效液相色谱(HPLC)法测定了2种扇贝粉从含量.处理1和处理2的扇贝粉分别含有71种和88种风味物质,分别含有208.78mg/g和140.26mg/g的氨基酸.添加β-环糊精与麦芽糊精的扇贝粉风味成分含量和种类显著多于未添加β-环糊精与麦芽糊精的,而添加了β-环糊精与麦芽糊精的扇贝粉AA含量低于未添加β-环糊精与麦芽糊精的扇贝粉AA含量,而麦芽糊精的添加有助于提高集粉率.     

高效液相色谱-串联质谱法测定乳制品中高氯酸盐

目的建立乳制品中高氯酸盐的高效液相色谱-串联质谱定量分析检测方法。方法样品采用1%乙酸-乙腈溶液(1∶2,V/V)提取,C18固相萃取柱净化,在IC-Pak~(TM) Anion HR色谱柱(4.6 mm×75 mm,6μm)上,以乙腈-乙酸铵溶液(60∶40,V/V)作为流动相,等度分离。采用液相色谱-质谱联用技术-电喷雾离子源多反应监测模式检测,内标法定量。结果高氯酸盐在0.1~10.0μg/L范围内具有良好的线性关系,牛奶和奶粉的定量限分别为1.0和3.0μg/kg;在三个添加水平下回收率范围在87.6%~122.0%之间,相对标准偏差(RSD)范围为2.0%~10.0%。结论本方法灵敏、准确,适用于乳制品中高氯酸盐的分析测定,具有较好的实际应用价值。     

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.