基质固相分散-高效液相色谱法同时测定烟草中的有机酸

研究了用基质固相分散-高效液相色谱法测定烟草中有机酸的方法。将烟草样品与石墨化碳黑球(W/W,1:4)充分研磨后装柱,用热水洗脱,洗脱液中的有机酸用高效液相色谱测定。以ZORBAX Stable Bound(4.6×50mm,1.8μm)快速分离柱为固定相,0.01mol/LNaH₂PO₄(pH2.98)和乙腈(体积比为98:2)为流动相,流速为2.0mL/min,柱温25℃,检测波长210nm。方法回收率为94%~98%;相对标准偏差为2.1%~3.0%;检出限为80~200μg/L。色谱分离时间不超过3.0min。用于实际样品分析,结果令人满意。      

高效液相色谱法同时测定常见水果中的四种有机酸

采用反相高效液相色谱法分别对芦柑、鸭梨、富士苹果和脐橙中的四种有机酸(酒石酸、苹果酸、柠檬酸和琥珀酸)进行了分析,色谱柱为VP-ODS,C18(150mm×4.6mm),以0.02 mol/L KH2PO4(pH=3.0)为流动相,流速为1mL/min,柱温为30℃,紫外检测波长为215nm,探讨了pH及其它条件对色谱分离的影响.四种有机酸的回收率为96.1%～112.9%,线性相关系数r＞0.999,准确、高效地测定了芦柑、鸭梨、富士苹果和脐橙中的有机酸含量.     

RP-HPLC法测定荔枝酒中的有机酸

建立一种快速测定荔枝酒中有机酸的反相高效液相色谱法.优化色谱条件为:Eclipse Plus C18反相柱(4.6×250mm,5μm),0.01 mol/L NH4H2PO4(pH=2.7)作为流动相,检测波长210nm,流速1.0mL/min,柱温30℃.在此条件下9种有机酸得到良好分离,所需时间只需9min.该方法具有良好的线性相关性(R＞0.9900),RSD为0.25%～1.21%(n=3),加标回收率为93.64%～101.80%.荔枝酒中有机酸含量在309mg/L～3299mg/L之间,随着储藏年份的增长,各种有机酸含量呈不同变化,发酵型与配制型荔枝酒中的有机酸组成和量比关系存在差异,形成不同荔枝酒独特的风味.     

反相HPLC法同时测定烟草中的6种有机酸

建立了用反相高效液相色谱法同时快速测定烟草中柠檬酸、苹果酸和草酸等6种有机酸的方法。采用的色谱柱为Hypersil C18(250mm×4.6mm,5μm),流动相0.01mol/L NaH2PO4(pH2.98)和无水甲醇(体积比为98∶2),流速为1.0mL/min,柱温25℃,检测波长210nm。有机酸的回收率为98.2%~104.3%;相对标准偏差为0.61%~3.38%;检出限0.04~0.53μg/mL,分析时间不超过7min。并分析了4种转光地膜和普通地膜覆盖的K326初烤烟叶中这6种有机酸的含量。     

高效液相色谱法同时测定果醋饮品中7种有机酸的含量

目的建立高效液相色谱法同时测定果醋饮品中的7种有机酸(柠檬酸、苹果酸、乳酸、酒石酸、富马酸、丁二酸及乙酸)含量。方法样品经稀释后过0.45μm水相滤膜,采用Welch Ultimate AQ-C18色谱柱(4.6 mm×250 mm, 5μm)分离,以0.1%磷酸和甲醇(97:3, V:V)为流动相进行等度洗脱,柱温为40℃,流速为0.5 mL/min,在波长210 nm处进行检测,外标法定量。结果 7种有机酸在12 min内完全分离,相关系数均在0.997以上,检出限为0.12～0.4mg/L,加标回收率为95.4%～101.5%,相对标准偏差为1.19%～3.59%。结论该方法适用于果醋饮品中7种有机酸含量的测定。     

基于新型立体结构的色谱固定相的高效液相色谱法检测分离7种有机酸

目的制备新型立体结构色谱固定相并开发新的高效液相色谱法(high performance liquid chromatography,HPLC)分离7种有机酸的方法。方法采用新型立体结构固定相对7种有机酸进行分离,以5%甲醇-95%10 mmol/L甲酸铵(pH=3.0)水溶液作为流动相进行等度洗脱;流速为1.0 mL/min;柱温:40℃;紫外检测波长:220 nm;进样体积:10μL,采用HPLC进行检测。结果制备了新型立体结构固定相,具有与常规C_(18)固定相相似的疏水作用,8 min内完全分离7种有机酸,且分离效果较好。结论本方法具有保留增强、快速及分离效果好等优势,可用于多种有机酸的分离测定。     

固相萃取-高效液相色谱法测定红糖中有机酸

建立可同时测定红糖中酒石酸、丙酮酸、乙酸、柠檬酸、琥珀酸、没食子酸以及乌头酸含量的固相萃取-高效液相色谱法。结果发现当检测器为二极管阵列紫外-可见光检测器,检测波长210 nm,XBridge C8色谱柱(250 mm×4.6 mm,5μm),柱温为35℃,流动相为0.1%磷酸∶乙腈溶液=99∶1,流速为0.7 mL/min,红糖中的7种有机酸能在15 min内均达到基线分离。检测限分别在0.005 2 mg/kg～0.77 mg/kg之间,标准曲线相关系数为0.999 6～1.000,精密性试验相对标准偏差值为1.1%～3.0%,样品的回收率在82.1%～108.6%之间。由此可见,此方法适用于快速测定红糖中7种有机酸含量。     

高效液相色谱法测定沙棘汁中7种有机酸

建立高效液相色谱法同时测定沙棘汁中7种有机酸的方法。其测定条件为以0.05mol/L KH2PO4溶液(用20%磷酸调节pH2.70)作为流动相,Sepax GP-C18为色谱柱、流速0.6mL/min、柱温30℃、紫外检测波长210nm。结果表明:7种有机酸能够得到很好的分离,各有机酸的线性相关系数r大于0.9925,回收率在93.7%～103.2%之间,相对标准偏差均小于4.0%。     

高效液相色谱法测定秘鲁鱿鱼肌肉中的有机酸

研究建立了高效液相色谱(HPLC)同时测定秘鲁鱿鱼肌肉中多种有机酸的方法。有机酸的分离采用Atlantis T3色谱柱(4.6 mm×150 mm,5μm),流动相为0.08 mol/L KH_2PO_4(pH 3.00),流速0.5 mL/min,柱温30℃,检测波长210 nm。丙酮酸、苹果酸、α-酮戊二酸、乳酸、乙酸、柠檬酸、富马酸、丁二酸、丙酸等9种有机酸均能够得到很好的分离,其相关系数均在0.999以上,相对标准偏差为0.03%~0.37%,有机酸的回收率为94.5%~105%。     

反相高效液相色谱法测定荔枝肉中10种有机酸

提出了一种利用高效液相色谱同时分析荔枝肉中10种有机酸的方法.在ZORBAX Eclipse Plus C18(4.6×250 mm,5 μm)色谱柱上,0.01mol/L磷酸氢二铵溶液(pH3.00)作为流动相,流速为1.00mL/min,紫外检测波长为213nm,柱温20℃时,能较好地分离和检测荔枝肉中的10种有机酸.该方法回收率为91.6%～109.3%,相对标准偏差为0.14%～1.72%,具有较好的准确度和精密度,方法简便,可应用于水果等的有机酸检测.     

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.     

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