离子色谱法测定茶叶中草甘膦的残留

目的建立一种简单、快捷测定茶叶中草甘膦残留量的离子色谱分析方法。方法样品经水提取后使用乙腈沉淀阴离子杂质,离心后取上清液依次过Dionex OnGuardⅡRP柱和Dionex OnGuardⅡAg/H柱,经IonPac AS11-HC离子色谱柱(含AG11-HC保护住)分离,用KOH淋洗液自动发生器(EG)进行梯度淋洗,抑制器采用外加水模式,电导检测器检测。结果草甘膦在0.006~12.5 mg/L范围内线性关系良好(相关系数为0.9998),方法的检出限为0.19 mg/kg,定量限为0.64 mg/kg,回收率为80.7%~98.1%,日内精密度(n=6)为1.8%~3.4%,日间精密度(n=5)小于5%。结论该方法具有净化效果好、定量准确、灵敏快速的特点,适用于茶叶中草甘膦残留的检测确证,能达到GB 2763-2014的检测要求。     

离子色谱法测定婴幼儿配方米粉中硫氰酸钠

建立了一种简单、快捷测定婴幼儿配方米粉中硫氰酸钠的离子色谱分析方法。样品用水提取后使用甲醇沉淀淀粉类杂质,离心后取上清液过On Guard RP柱净化后,经Ion Pac AS16离子色谱柱（含AG16保护住）分离,用KOH淋洗液自动发生器进行梯度淋洗,抑制器采用外加水模式,电导检测器检测。结果表明硫氰酸钠在0.010～10.0 mg/L范围内线性关系良好（相关系数R2为0.999 0）,方法的检出限为0.27 mg/kg,定量限为0.9 mg/kg,回收率为80.5%～98.1%,日内精密度试验相对标准偏差（RSD）（n=5）为1.8%～4.7%,日间精密度试验RSD（n=5）＜5%。将该方法应用于20个样品的检测,其中5个样品检出硫氰酸钠,含量0.95～2.04 mg/kg。该方法具有净化效果好、定量准确、灵敏快速的特点,适用于婴幼儿配方米粉中硫氰酸钠的检测。     

非抑制型电导检测离子排斥色谱法测定江西白酒中的有机酸

建立了非抑制型电导检测离子排斥色谱法分离并测定6种有机酸(草酸、酒石酸、苹果酸、甲酸、琥珀酸、乙酸)的方法.以Ion Pac ICE-AS6色谱柱为分离柱,选用背景较低的稀苯甲酸溶液为淋洗液,考察了淋洗液浓度、流速、色谱柱温度对分离和测定有机酸的影响.通过实验确定最佳的色谱条件为:1.0mmol/L苯甲酸溶液作为淋洗液,流速0.45ml/min,柱温35℃.所测有机酸的检测限为0.0341～0.9045mg/L,相对标准偏差在0.13%～5.12%之间(n=5),回收率为90.75%～108.5%,方法具有较好的准确度和精密度.该法用于江西5个不同生产厂家23个白酒样品中有机酸的测定,结果令人满意.     

离子色谱法测定食品中草铵膦、草甘膦和 氨甲基膦酸的残留

目的建立一种简单、快捷、同时测定食品中草铵膦、草甘膦、氨甲基膦酸残留量的离子色谱分析方法。方法样品用水提取后使用乙腈沉淀氨基酸和蛋白质,离心后取上清液依次过Dionex OnGuardⅡRP柱和Dionex OnGuardⅡAg/H柱,流出液经IonPac AS11-HC离子色谱柱(含AG11-HC保护住)分离,用KOH淋洗液自动发生器(EG)进行梯度淋洗,抑制器采用外加水模式,电导检测器检测。结果结果表明草甘膦和草铵膦在0.02~6.25 mg/L、氨甲基膦酸在2.00~62.5 mg/L范围内线性关系良好,相关系数均大于0.999,Gly、Gluf和AMPA的方法检出限分为0.047、0.033和0.520 mg/kg,定量限分为0.16、0.11和1.73 mg/kg,回收率为80.1%~109%,日内精密度(n=6)为0.91%~12.5%,日间精密度(m=5)小于10.0%。结论该方法具有净化效果好、定量准确、灵敏快速的特点,适用于食品中草铵膦、草甘膦、氨甲基膦酸残留量的检测确证,能达到GB 2763-2014的检测要求。     

离子色谱串联MSQ质谱法测定饲料中的亚硝酸盐

建立了一种测定饲料中亚硝酸盐的离子色谱串联MSQ质谱的分析方法。样品经超声提取后,过Ag柱、Na柱、RP柱除杂质,以AS20 2×250 mm色谱柱分离,用氢氧化钾淋洗液发生器自动淋洗,采用梯度淋洗方式,电导检测器定量,质谱定性。结果表明：方法检出限为0.2 mg/kg,标准品在0.02～ 5.00 mg/kg内呈良好线性关系,相关系数为0.999 7,加标回收率为81.0%～ 102.0%。     

分散固相萃取-气相色谱法同时检测食品塑料 包装材料中7种烷基胺

目的建立了分散固相萃取-气相色谱法(dispersive solid-phase extraction-gas chromatography,dSPE-GC)同时测定食品塑料包装材料中7种有机胺类物质的残留量。方法样品经二氯甲烷超声萃取15 min,采用25 mg C_(18)、25 mg PSA和10 mg MWCNT固相萃取剂对提取液进行净化,采用DB-1701色谱柱进行分离并进行气相色谱测定。同时对固相萃取剂的种类和用量、色谱柱等条件进行了优化。结果 7种烷基胺类物质在1.0~100 mg/L浓度范围内线性关系良好,相关系数为0.9937~0.9996;方法检出限为2.6~5.0 mg/kg;添加水平为5.0、10.0和50 mg/kg时,7种目标物的平均回收率为81.9%~107%,日内精密度(n=6)为1.9%~5.3%;日间精密度(n=5)为4.5%~9.1%。对市售10个塑料包装材料进行测定,其中1个样品检出青霉胺,含量为9.1 mg/kg。结论本方法快速准确,可适用于食品塑料包装材料中烷基胺类物质的测定。     

离子色谱法测定白砂糖中氟的含量

本文建立离子色谱法测定白砂糖中氟含量的方法。采用IonPac AS18阴离子色谱柱分离,氢氧化钾溶液等度淋洗,抑制电导检测。仪器检出限为0.02 mg/L,加标回收率为99.21%～101.1%,相对标准偏差0.82%～1.23%（n=6）。结果表明,方法简便快速准确。     

离子色谱法同时测定奶粉中硝酸盐和多种磷酸盐

为了对硝酸盐和多种磷酸盐的稳定性进行研究,建立了离子色谱同时测定奶粉中硝酸盐和多种磷酸盐的分析方法。以水为提取液,超声辅助提取目标成分,沉淀蛋白,过柱净化,调节样液p H后,用AS11-HC阴离子交换柱进行分离,Na OH溶液梯度淋洗,电导检测器检测。试验结果表明,5种阴离子NO_3~-,P_2O_7~(4-),P_3O_(10)~(5-),P_3O_9~(3-),P_6O_(18)~(6-)分离效果满意,线性关系良好,相关系数为0.999 5~1.000 0,方法检出限为0.04~0.5 mg/kg,平均加标回收率为85.1%~100.5%,相对标准偏差为0.7%~7.6%。该方法灵敏度高,线性良好,精密度高,操作简便,检测时间短。     

离子色谱法测定诺丽果粉中常见有机酸和阴离子含量

采用戴安ICS-5000离子色谱建立了诺丽果粉中14种有机酸和阴离子的分离测定方法。实验利用电导检测器对诺丽果粉中常见有机酸和阴离子进行测定。采用Ion Pac AS11-HC分析柱(带Ion Pac AG11-HC保护柱)为色谱柱,以ASRS 300(4 mm)自循环电抑制模式,KOH作为淋洗液作梯度淋洗,流速为1.0 m L/min,柱温30℃为色谱条件实现诺丽果粉中有机酸和阴离子理想分离。方法拥有良好的线性(r≥0.9988)、检出限(≤0.508 mg/L)、回收率(91.50%~107.22%)和重复性(RSD 0.18%~5.2%,n=8)。诺丽果粉中含有的有机酸和阴离子主要是乳酸、苹果酸、草酸、柠檬酸、氯离子、硫酸根和磷酸根。其中乳酸含量为5.893 mg/g,苹果酸含量为74.631 mg/g,草酸含量为9.631 mg/g,柠檬酸含量为10.826 mg/g,氯离子含量为27.930 mg/g,硫酸根含量为4.226 mg/g,磷酸根含量为7.747 mg/g,丙酮酸含量为3.965 mg/g,其余几种分析组分未检出。该方法准确可靠,可用于诺丽果粉中有机酸和无机阴离子的定性、定量分析。     

离子色谱法测定酒中的有机酸和无机阴离子

建立用离子色谱/电导检测法测定酒类中有机酸和无机阴离子的分析方法。样品经水稀释,经0.45 μm滤膜过滤后直接进样检测;选用Ionpac AS11阴离子交换分离柱,氢氧化钾淋洗液梯度洗脱,流速1.0 mL/min,以抑制电导检测器检测。该方法对11种有机酸和5种无机阴离子具有良好的线性,相关系数在0.9909~0.9997之间;准确度和精密度良好,样品加标回收率在81.0~117.8%之间,RSD小于5.0%;检出限低,在0.015~0.152 mg/L之间。该方法线性范围广,准确性和精密度良好,操作较简便,结果满意,能满足日常检验要求。     

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