以羟丙基-β-环糊精为流动相添加剂测定宣木瓜中齐墩果酸与熊果酸

采用高效液相色谱法,在流动相中添加羟丙基-β-环糊精测定宣木瓜中齐墩果酸与熊果酸以提高分离度。色谱条件为色谱柱Kromasil 100-5-C_(18)(250 mm×4.6 mm,5 μm);流动相:甲醇-12 mmol/L HP-β-CD-磷酸-三乙胺(体积比为87:13:0.05:0.1);流速0.8 mL/min;柱温20 ℃;检测波长210 nm;进样量20 μL。结果表明,齐墩果酸在5～500 μg/mL范围内线性关系良好(r=0.9989),平均回收率在(96.53±1.43)%～(97.48±0.36)%,相对标准偏差在0.37%～1.49%;熊果酸在5～500 μg/mL范围内线性关系良好(r=0.9996),平均回收率在(96.89±1.71)%～(98.76±1.17)%,相对标准偏差在1.18%～1.77%。该方法可提高齐墩果酸与熊果酸的分离效果,分离度达到2.74,操作简便、结果准确、重现性好,能够准确测定宣木瓜中齐墩果酸与熊果酸的含量。     

RP-HPLC法测定核桃外果皮中齐墩果酸的含量

建立核桃外果皮中齐墩果酸含量测定的反相高效液相色谱法(RP-HPLC),采用色谱柱为Intersil ODS(150 mm×4.6 mm,5μm);流动相为甲醇:水:冰乙酸(265:35:0.1,V/V);流速0.8 mL/min;进样量20 μL;检测波长为210 nm;柱温30℃.结果表明,齐墩果酸进样量在0.728～7.28 μg(r=0.999 7)范围内呈现良好的线性关系,齐墩果酸平均回收率(n=9)为101.1%,相对标准偏差(RSD)为2.44%.测得核桃外果皮中齐墩果酸含量为2.1 mg/100 g.该方法简便快速,结果可靠准确,重现性和稳定性好.     

反相高效液相色谱测定不同品种皱皮木瓜中齐墩果酸和熊果酸含量

采用反相高效液相色谱法测定鲜皱皮木瓜中齐墩果酸和熊果酸含量,并进行方法学考察.采用Agilent C18 柱(4.6mm×250mm,5μm);流动相:甲醇-1%HAc水溶液(85:15);流速:0.6ml/min;柱温:35℃;检测波长:210nm.齐墩果酸在0.162～6.48 μg范围内线性良好,回归方程为y=512802x 19211(R2=0.9997),平均回收率分别为100.2%,RSD为0.9%(n=6);熊果酸在0.391～15.62μg范围内线性良好,回归方程为y=50865x-5090.4(R2=0.9998),平均回收率为100.0%,RSD为1.1%.该方法简便准确,重现性好,适用于鲜皱皮木瓜中齐墩果酸和熊果酸的定量分析.     

RP-HPLC法测定新疆6种红枣中齐墩果酸和熊果酸的含量

采用反相高效液相色谱法测定新疆不同品种红枣中齐墩果酸和熊果酸的含量。采用Kromasil C18柱(4.6 mm×250 mm,5μm),流动相为甲醇-0.03 mol/L的磷酸二氢钠(磷酸调pH至3.0)(90:10),流速为0.8 mL/min,检测波长为210 nm,柱温25℃。上述色谱条件下红枣中齐墩果酸、熊果酸可完全分离,线性范围分别为齐墩果酸0.4～ 2.0μg(r=0.9998),熊果酸0.448～ 2.24μg(r=0.9999);平均回收率分别为齐墩果酸99.4%,RSD=1.33%,熊果酸99.6%,RSD=1.43%(n=6)。该方法快速、准确、可靠,可用于红枣中齐墩果酸和熊果酸含量的同时测定。     

正交法优选宣木瓜叶齐墩果酸回流提取工艺

试验首次对宣木瓜叶进行TLC定性研究,发现其中含有具有活性的“齐墩果酸”。在此基础上,采用正交法对宣木瓜叶齐墩果酸的回流提取工艺进行优化。研究结果表明,提取最佳工艺条件为:95%乙醇、料液比1∶10、提取时间2h、提取温度60℃。以提取物为基准测得宣木瓜叶中齐墩果酸量为2.86%,而索氏抽提法测得叶中齐墩果酸为3.16%,由此可得,本试验提取效率达90.5%。为宣木瓜叶的综合开发利用提供试验依据。     

高效液相色谱法测定野木瓜中齐墩果酸的含量

采用高效液相色谱法,对野木瓜中齐墩果酸的含量进行了测定.实验表明在色谱柱为Shimpack VP-ODS柱(250 nm×4.6 mm,5 μm)、流动相为乙腈-1.1%乙酸水(94∶6)、流速为0.5 mL/min、检测波长205 nln、柱温为室温、进样量20 μL时,分离检测效果最佳,齐墩果酸含量在0.03～0.15 mg/mL范围内线性关系良好、精密度高、重现性好,回归方程:v=3.81424×10-8x-0.00240239,相关系数r=0.9994.平均加样回收率为100.54%.实验测得野木瓜中齐墩果酸平均含量为0.1055%.     

苦丁茶中熊果酸和齐墩果酸的提取及含量测定

采用甲醇超声提取,高效液相色谱测定苦丁茶中熊果酸及齐墩果酸含量.最佳色谱条件为:Agilent HC-C18(250mm×4.6mm,5μm)色谱柱,流动相V(甲醇):V(水):V(磷酸)=87:13:0.03,流速1.0mI/min,紫外检测波长215nm.通过对不同样品的测定,结果表明:冬青科苦丁茶中熊果酸及齐墩果酸含量较高,而木樨科苦丁荼中基本不舍熊果酸及齐墩果酸,且含量随贮存时间延长而下降.     

RP-HPLC法测定石榴不同部位中熊果酸和齐墩果酸的含量

采用超声技术提取石榴不同部位中熊果酸和齐墩果酸,建立RP-HPLC法测定其含量。色谱柱为KromasilC18柱(250mm×4.6mm,5μm),流动相为甲醇-0.2%磷酸水溶液(87∶13),光电二极管阵列检测器,检测波长210nm,流速0.8mL/min,柱温28℃。熊果酸进样量在0.443~7.088μg,齐墩果酸进样量在0.247~3.952μg时呈现良好的线性关系,相关系数均为0.9999,平均加样回收率分别为98.53%和98.36%,RSD分别为1.3%和1.5%。本方法灵敏、准确,重现性好,可用于石榴不同部位中熊果酸和齐墩果酸含量的测定。     

高效液相色谱法(HPLC)测定山楂片中的熊果酸和齐墩果酸

建立了高效液相色谱同时测定山楂片中熊果酸和齐墩果酸含量的方法。色谱条件：色谱柱Hypersil BDS C18（4.6mm×200mm,5μm）,柱温为25℃,UV检测波长2l0nm,流动相为甲醇-磷酸水溶液（pH=3.0）（85∶15）,流速为0.5mL/min。结果表明：熊果酸和齐墩果酸的线性范围38.0μg/mL～600μg/mL（r=0.9991）和12.5μg/mL～200μg/mL（r=0.9994）,平均回收率分别为99.06%和99.17%,RSD分别为1.43%（n=5）和2.49%（n=5）;该方法简便、准确,适合于山楂片中熊果酸和齐墩果酸含量的测定。     

RP-HPLC法测定紫苏子、白苏子中乌索酸和齐墩果酸含量

采用反相高效液相色谱法测定紫苏子和白苏子中乌索酸和齐墩果酸含量,色谱柱为Kromasil C18柱(250 mm×4.6 mm,5μm),流动相为甲醇—水(87:13),光电二极管阵列检测器,检测波长210 nm,流速0.8 ml/min,柱温28℃。乌索酸进样量在0.10～4.00μg,齐墩果酸进样量在0.05～2.00μg时呈现良好线性关系,平均加样回收率分别为100.6%和98.7%,RSD分别为1.6%和1.2%。方法灵敏、准确,重现性好,可用于乌索酸与齐墩果酸含量测定。     

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