电感耦合等离子体质谱法测定巧克力中的18种元素

采用微波消解处理巧克力样品,建立了电感耦合等离子体质谱(ICP-MS)法测定Na、Mg、P、K、Ca、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Sr、Mo、Pb等18种微量元素的分析方法.样品采用HNO3+H2O2混合酸微波辅助消解,优化了仪器的最佳条件.通过添加标准液进行加标回收,结果表明,所有待测元素的相对标准偏差(RSD)均小于4.60％,回收率在89.60％～106.12％之间.该法准确度高,精密好,并能同时进行多种元素测定等优点,完全能满足样品测定要求,可为巧克力中无机元素的快速检测提供科学依据.     

ICP-OES法测定方便面中微量元素的研究

采用微波辅助消解样品,建立了轴向观测电感耦合等离子体发射光谱(ICP-OES)法同时测定方便面中Na、Mg、Al、K、Ca、Mn、Fe、Cu、Zn、Mo、Cd、Ba等12种微量元素的分析方法。确定了仪器的最佳工作条件,选择了各待测元素合适的分析谱线,采用Y为内标元素消除了测定过程中的干扰。结果表明方法的检出限为0.16～18.15μg/L,采用硬质小麦标准物质NIST 8436进行方法验证,结果准确可信。该法具有准确度高,精密度好等优点,可用于方便面的质量控制和安全评价。     

电感耦合等离子体质谱测定茎瘤芥(榨菜)中无机元素的研究

采用微波消解法处理茎瘤芥样品,建立了电感耦合等离子体质谱(ICP-MS)法同时测定其中Mg、P、K、Ca、Mn、Fe、Ni、Cu、Zn、As、Se、Mo、Cd、Sb、Hg、Pb共16种无机元素含量的分析方法。采用碰撞反应池(CRC)技术消除了多原子离子质谱干扰,以Rh为内标元素校正了质谱分析中基体效应并补偿了信号漂移,研究了不同碰撞/反应气流速对待测元素预估检测限(EDL)的影响。16种待测元素的检出限为0.006~0.20μg/L,利用标准参考物质(GBW10049,大葱)验证了分析方法的准确度和精密度,结果表明,标准物质的分析结果与参考值基本一致,方法可快速、灵敏、准确地测定茎瘤芥中16种无机元素含量。     

电感耦合等离子体质谱法测定玉米和小麦淀粉中无机元素的研究

比较微波消解和石墨消解对电感耦合等离子体质谱(ICP-MS)测定玉米粉和小麦粉中6种元素的影响,确定最佳的样品前处理方法。通过微波消解和石墨消解分别对玉米粉和小麦粉的成分分析标准物质进行消解,用ICP-MS测定其中的6种元素(Pb、Cd、Cr、Al、As、B)的含量,与标准参考值作对比,并测定各元素的回收率。结果表明:微波消解法对样品处理更彻底,测定值更接近参考值,受环境影响小,回收率在90%~105%区间内的达83%。     

土豆中微量元素的质谱分析

对土豆样品采用HNO3+H2O2混合酸消解体系进行微波消解处理制样,用电感耦合等离子体质谱(ICP-MS)法同时测定土豆中Na、Mg、Al、P、K、Ca、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Pb共16种微量元素的含量.详细地研究了样品的前处理条件,选用Rh作内标元素校正基体效应和信号漂移,该方法对16种待测元素的检出限为0.005 ～0.236μg/L,通过添加标准进行加标回收,所有待测元素的回收率在92.20％～109.65％之间,相对标准偏差(RSD)均小于3.18％,结果准确可靠.该法可为土豆中微量元素的快速检测提供科学依据.     

ICP-MS半定量分析法测定食品中39种重金属元素

采用微波消解-电感耦合等离子体质谱法(ICP-MS),建立一种同时测定食品中钙、铁、钾、镁、铝和砷等39种金属元素的半定量检测方法。食品样品经微波消解后,以钪、锗、铟、铼、铋作为标准物质,采用ICP-MS半定量分析法同时测定食品中重金属元素的含量。采用国家标准物质GBW10014(圆白菜)和GBW10024(扇贝)对方法的准确性进行验证,测定值与参考值基本一致,偏差为-29.O%~24.1%,该方法简便、快速、准确度高,能快速测定样品中存在的重金属元素及浓度范围,可应用于食品中重金属元素含量扫描分析,快速测定食品中重金属元素信息,为食品安全评估提供更详细、综合性的科学依据。     

电感耦合等离子体质谱法测定牛初乳粉中痕量硒的干扰探讨

目的 分析样品基体给检测结果造成的增敏效应影响,建立一种能消除待测样品中基体的干扰,从而准确测定痕量硒的电感耦合等离子体质谱的检测方法。方法 样品经硝酸消解后, 采用标准加入法,标准溶液加入的体积不大于待测液体积2%的前提下,在氦气模式下以元素特定质量数定性,以待测元素质谱信号与内标元素质谱信号的强度比与待测元素的浓度成正比进行定量分析。结果 样品基底对硒有增敏效果采用标准加入法能很好消除样品基底干扰,检测5种标准物质的硒含量均在标示值范围内。工作曲线相关系数达到0.998,精密度试验的相对标准偏差为3.2%。结论 该方法相对外标法能更准确对痕量硒进行定量,适合测定基底复杂存在干扰的样品,对相同或相近的样品可以共用相同工作曲线测定硒含量。     

超级微波消解-电感耦合等离子体发射光谱测定小麦中总铝含量

目的比较不同前处理消解方法,建立电感耦合等离子体发射光谱法(inductively coupled plasma optical emission spectrometry,ICP-OES)测定小麦样品中总铝的准确分析方法。方法采用4种样品前处理方法:微波消解(硝酸-双氧水体系)、微波消解(硝酸-氢氟酸-双氧水体系)、微波消解(硝酸-氢氟酸-盐酸体系)、超级微波消解(硝酸-氢氟酸-双氧水体系),消化标准参考物质大米(GBW10045)和玉米粉(GBW10012),采用ICP-OES法测定,同时用添加回收实验验证方法的准确性与可靠性。结果采用超级微波消解方法(硝酸-氢氟酸-双氧水体系)时,标准参考物质的铝含量测定结果在标准参考值范围内,采用其他样品前处理方法时的测定结果远低于参考值范围。该方法在0.04~5.0 mg/L浓度范围内线性关系良好,r=0.9999,方法定量限为2.0 mg/kg,回收率为91%~118%,相对标准偏差(relative standard deviation,RSD)为1.4%~4.5%。结论小麦样品中可能存在铝被硅包裹的现象,采用硝酸-氢氟酸-双氧水体系超级微波消解方式能将其消解完全,使检测结果更加准确,该法可用于小麦样品中总铝的测定。     

食品中铝含量国标测定法的改进

目的通过优化微波消解试剂和微波消解条件,解决国标推荐方法对生物样品消解不彻底的问题,使其能够准确测定食品中铝含量。方法采用国标推荐的微波消解方法和优化后的微波消解方法迚行样品的前处理,消解河南小麦、芹菜、猪肝、大虾和粉丝粉条等标准参考物质,采用电感耦合等离子体发射光谱法测定铝含量。结果采用国标推荐的微波消解前处理方法,试样测定结果进低于参考值。采用优化的微波消解程序(硝酸-氢氟酸体系),标准参考物质的铝含量测定结果较为接近标准参考值。铝含量在0～10.0μg/mL范围内线性关系良好(r=0.9998),标准参考物质中铝含量的回收率为71.9%～110%,相对标准偏差为1.3%～6.3%。结论硝酸-氢氟酸体系与优化的微波消解程序方法能将样品消解更为彻底,使检测结果更加准确,该法可用于食品中铝含量的测定。     

电感耦合等离子体质谱法测定枸杞中16种稀土元素

建立了微波消解-电感耦合等离子质谱法(ICP-MS)测定枸杞中16种稀土元素(La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y和Sc)含量的分析方法。采用微波消解对枸杞样品进行前处理,应用ICP-MS进行测定,以Rh为内标元素对定量结果进行校正。结果表明,该方法线性相关系数大于0.9999,方法检出限范围为0.009~0.821 μg/kg,定量限范围为0.030~2.736 μg/kg,加标回收率(n=6)为86.0%~108.6%,相对标准偏差(RSD)为1.25%~9.14%。选择国家标准物质胡萝卜(GSBW10047)验证方法的可靠性,待测元素测定值与标准值基本一致。该方法具有简单、快速、灵敏、准确、线性范围宽等特点。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.