固相萃取-高效液相色谱法测定酱油中10种防腐剂

文章建立了固相萃取-高效液相色谱法测定酱油中10种防腐剂的检测方法.方法采用90%甲醇提取、沉淀后,滤液经PEP-SPE固相萃取柱净化,采用Plus C18柱:5 μm,250 mm×4.6 mm;流动相:乙腈为0.01 mol/L磷酸二氢钾溶液(pH=4.0)(梯度洗脱).流速:1.0 mL/min,检测波长230 nm和254 nm;柱温30℃;进样量10μL.该方法的检出限在1.0～2.0 mg/L,线性范围1.0～100.0 mg/L,加标回收率72.8%～100.9%之间.相对标准偏差(RSD)0.42%～6.87%(n=4),该方法简单、快速、灵敏度高,并具有良好的精密度与准确度,可作为酱油中检测这10种防腐剂的有效定量方法.     

固相萃取－离子对色谱法测定酱油与黄豆酱中的三聚氰胺

建立了固相萃取-离子对色谱法测定酱油与黄豆酱中的三聚氰胺。样品经甲醇提取,WatersMCX固相萃取柱净化。分析时用InertsillODS-SPC18色谱柱(5μm,4.6×250mm)分离。水(缓冲液:0.01moL/L柠檬酸+0.01moL/L辛烷磺酸钠,pH=3.0)∶乙腈=92∶8(V/V)溶液为流动相,流速1.0mL/min,在紫外波长240nm下检测。三聚氰胺在0.02～2.00mg/L的范围内,有良好的线性关系(r2=0.9999),方法检出限为1.0mg/kg,加标回收率在83.5%～109.3%范围内,相对标准偏差小于5.0%。     

高效液相色谱法测定牛奶及奶粉中免疫球蛋白含量

建立高效液相色谱法(HPLC)测定牛奶及奶粉中免疫球蛋白含量。在磷酸盐缓冲液条件下通过HiTrapTM Protein G HP亲和柱结合免疫球蛋白,甘氨酸盐缓冲液洗脱,用CAPCELL PAK C18色谱柱在流动相为乙腈︰0.1%三氟乙酸(5︰5),流速1.0 mL/min,室温条件下进行分离,检测波长280 nm,进样量10μL。Ig G在5～200μg/m L质量浓度范围内相关系数R2为0.999 6,线性关系良好。牛奶基质检出限为10.0 mg/kg,定量限为30.0 mg/kg;奶粉基质检出限为100 mg/kg,定量限为300 mg/kg。在牛奶基质加标10～100 mg/kg、奶粉基质加标100～1 000 mg/kg时,方法回收率为92.4%～98.0%,相对标准偏差(n=6)为0.914%～1.52%,精密度良好,准确度高,可适用于牛奶及奶粉中IgG含量的测定。     

加压毛细管电色谱测定乳及乳制品中三聚氰胺

研究建立利用加压毛细管电色谱(p CEC)测定乳及乳制品中三聚氰胺的分析方法。样品采用2%三氯乙酸水溶液超声提取,阳离子固相萃取柱(MCX)净化,提取液经C18反相毛细管电色谱柱分离,流动相乙腈-10 mmol/L辛烷磺酸钠溶液(p H 3.0)=15+85,泵流速0.05 m L/min,分离电压-2 k V,紫外检测器240 nm检测。该方法在1.0 mg/kg~100 mg/kg质量浓度范围内线性关系良好(R2=0.999),在牛奶和酸奶中的定量限为2.5 mg/kg,在奶粉中的定量限为10 mg/kg,加标回收率为78.9%~93.5%,相对标准偏差小于5%。     

离子交换色谱-紫外检测法测定乳制品中三聚氰胺

建立离子交换色谱-紫外检测法测定乳制品中三聚氰胺。样品直接用水和乙腈提取,分析时用LC-SCX离子交换色谱柱分离,浓度为0.05 mol/L磷酸二氢钾溶液（pH值为3.0）-乙腈（70∶30）为流动相,流速1.0 mL/min,在紫外波长240 nm下检测。三聚氰胺在0.5～100.0 mg/L的范围内,质量浓度与色谱峰面积呈良好的线性关系（r=0.9999）,最低检出限为1.0 mg/kg,加标回收率在93.8%～102.5%范围内,相对标准偏差（RSD）小于3.5%。该方法简便、快速、准确,能够满足检测要求。     

HPLC示差折光分析法测定人参果蔬发酵饮料中果糖、葡萄糖、蔗糖含量

本研究用HPLC示差折光分析法测定人参果蔬发酵饮料中果糖、葡萄糖、蔗糖的含量。实验采用NH2P-50 4E柱,流动相为乙腈-水(75:25),流速1.0 m L/min,检测器池温度35℃,柱温25℃,进样量10μL。此法相对标准偏差(RSD)为0.85%~0.92%(n=5),加标回收率为96.54%~99.42%,糖类质量浓度在1.0~20 mg/m L内呈现良好的线性关系,相关系数在0.998 3(n=6)以上。该法适用于果蔬饮料制品的糖类测定。     

固相萃取-液相色谱法测定食品中脱氢乙酸

建立了固相萃取-高效液相色谱法测定食品中脱氢乙酸的方法。方法采用C18(5μm,4.6mm×250mmi.d)反向色谱柱,流动相:V(甲醇)∶V(0.02mol/L乙酸铵溶液)=7∶93,流速1.0mL/min,检测波长290nm,柱温30℃,进样量5μL。该方法的检出限在1.5～4.8mg/kg,线性范围0.01～0.08mg/mL,相对标准偏差(RSD)0.95%～2.10%(n=6),加标回收率94.5%～100.4%。该方法简单、快速、灵敏度高,并具有良好的精密度与准确度,可作为食品中检测脱氢乙酸的有效定量方法。     

高效液相色谱法同时测定食品中安赛蜜、苯甲酸、山梨酸、糖精钠以及脱氢乙酸

建立食品中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸等甜味剂和防腐剂的高效液相色谱测定法。方法采用C18(5um,4.6mm×150mmi.d)反相色谱柱,流动相:v(甲醇)∶v(0.02moL/L乙酸铵溶液)=(5∶95),流速1.0mL/min,检测波长230nm,柱温30℃,进样量5μL。样品的检出限1.5～4.4mg/kg,线性范围1～10mg/L,加标回收率95.5%～103.6%,相对标准偏差为0.95%～2.81%(n=6)。该法具有样品预处理简单,灵敏度高,分析时间短等优点,可用于食品样品的直接测定。     

高效液相色谱同时测定植物饮料中7种植物毒素

建立了同时检测植物饮料中原百部碱、香豆素、黄连素、山道年、细辛脑、长叶薄荷酮和芦荟苷A 7种植物毒素含量的高效液相色谱法。试样经HLB固相萃柱富集净化,甲醇洗脱,氮吹浓缩后用流动相起始梯度定容至1.0 mL,经Welch Ultimate XB-C18色谱柱（4.6 mm×150 mm,5 μm）分离,以甲醇-10 mmol/L乙酸铵水溶液（pH=3）为流动相梯度洗脱,通过紫外检测器进行检测。7种植物毒素化合物在0.20～100.00 mg/L范围内线性关系良好,相关系数均＞0.99,方法的检出限分别为0.2～6.5 μg/kg,定量限为0.8～21.6 μg/kg。分别对3种植物饮料样品进行加标回收率实验,回收率为67.1%～104.0%,相对标准偏差（n=6）为1.08%～5.12%。该方法操作简单,具有较高的准确度和精密度,适用于植物饮料中7种植物毒素含量的检测。     

高效液相色谱法同时测定果冻中9种添加剂

建立了果冻中9种添加剂的高效液相色谱测定法。采用ZORBAX Eclipse XDB-C18,以甲醇和乙酸铵为流动相,梯度洗脱,流速为1.0 m L/min,检测波长为230、415、515、630 nm,柱温30℃,采用高效液相色谱DAD检测器进行测定。该方法的检出限介于0.25 mg/L~0.5 mg/L之间,加标回收率95.6%~114.0%,相对标准偏差为1.09%~4.28%(n=4)。     

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