固相萃取-高效液相色谱法测定水产品中的甲基睾酮残留量

建立水产品中甲基睾酮残留量的固相萃取-高效液相色谱测定方法。样品经乙醚振荡提取、蒸发浓缩、正己烷除脂、LC-C18柱净化后吹干定容,以甲醇-0.1%甲酸溶液(75:25,V/V)为流动相经反相高效液相色谱检测定量。方法在7.0～200μg/kg添加范围内的平均回收率为82.0%～86.0%,相对标准偏差均小于7%,定量限为7.0μg/kg。     

高效液相色谱-串联质谱法同时测定鸡肉、 鸡蛋中喹乙醇和卡巴氧及代谢物残留

目的建立高效液相色谱-电喷雾电离串联质谱法测定鸡肉、鸡蛋中喹乙醇、卡巴氧及其代谢物残留量的分析方法。方法组织样品中的卡巴氧和喹乙醇用乙腈-乙酸乙酯(1:1, V:V)溶液提取;代谢物的提取用蛋白酶酶解后经盐酸溶液酸化,采用阴离子交换固相萃取柱净化和富集。分析样品以0.1%甲酸溶液-甲醇进行梯度洗脱,经Waters Xbridge C_(18)色谱柱分离,以液相色谱串联质谱多反应监测(multiple reaction monitoring,MRM)正离子模式进行检测。结果 5种喹喔啉类药物在0.5～50ng/mL浓度范围内线性良好,相关系数r~2为0.9956～0.9988;该方法的检出限和定量限分别为0.1～0.5μg/kg和1.0～2.0μg/kg;鸡蛋和鸡肉样品中,喹乙醇、卡巴氧、脱氧卡巴氧、喹喔啉-2-羧酸和3-甲基喹喔啉-2-羧酸在0.2～2.0μg/kg加标水平的平均回收率为85.1%～108.2%,日内精密度为4.9%～8.7%,日间精密度为6.2%～11.7%。结论该方法简单有效、回收率好、灵敏度高、特异性好,能满足日常检测的需求。     

增强型除脂固相萃取技术结合超高效液相色谱- 串联质谱法测定动物源性食品中五氯酚残留量

目的建立增强型除脂固相萃取技术结合超高效液相色谱-串联质谱法测定动物源性食品中五氯酚残留量的分析方法。方法样品经8%三乙胺乙腈:水(80:20,V:V)提取,经EMR-Lipid固相萃取柱净化,以5 mmol/L乙酸铵溶液(含0.1%甲酸)-甲醇作为流动相, Waters ACQUITY BEH C_(18)(50 mm×2.1 mm, 1.7μm)进行色谱分离,在电喷雾负离子模式下,多反应监测(multiple reaction monitoring,MRM)方式进行测定,基质匹配外标法定量。结果猪肉、猪肝、鱼、河虾、蟹、牛奶等6种基质中五氯酚在0.5～10 ng/mL范围内线性良好,相关系数r0.997,方法检出限范围为0.1～0.3μg/kg,定量限范围为0.3～0.5μg/kg,在1.0、5.0、10.0μg/kg3个浓度水平下6种基质中回收率范围为81%～98%,相对标准偏差范围为1.74%～4.78%之间(n=6)。结论该方法简单快速、准确可靠,经济环保,重复性好,适用于动物源性食品中五氯酚残留量的测定。     

固相萃取-液相色谱-串联质谱法测定禽蛋中五氯酚及其钠盐残留量

研究建立了禽蛋中五氯酚及其钠盐的液相色谱-串联三重四极杆质谱测定方法。样品经体积分数5%三乙胺的乙腈-水溶液(7:3,V/V)提取，混合型阴离子固相萃取柱净化，经ACQUITY UPLC BEH C₁₈(100 mm×2.1 mm,1.7μm)色谱柱分离，以5 mmol/L乙酸铵(含0.1%甲酸)溶液和乙腈作为流动相，进行梯度洗脱，采用多反应监测负离子模式监测，基质匹配标准曲线外标法定量。在该优化条件下，五氯酚及其钠盐在1.0～20 ng/mL浓度范围内线性关系良好，相关系数均大于0.998，检出限为0.5μg/kg，定量限为1.0μg/kg。在不同浓度添加水平下(1.0、2.0、5.0μg/kg)，平均回收率为74.0%～101.3%，相对标准偏差为0.78%～6.56%(n=6)。该方法简单、高效、准确，提取液经冷冻处理后避免了净化时固相萃取柱堵塞情况出现，缩短实验时间，优化后的实验方法适用于禽蛋中五氯酚及其钠盐的残留检测。     

LC-MS/MS测定鸡蛋、鸡肉和蛋糕中氟虫腈及代谢物残留量

建立液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)法测定鸡蛋、鸡肉和蛋糕中氟虫腈及其代谢物残留量的方法。样品经酸性乙腈提取,经Cleanert PEP Plus(60 mg/3 m L)固相萃取柱净化,Agilent Eclipse plus C18色谱柱(2.1 mm×100 mm,1.8μm)分离,以0.1%甲酸乙腈溶液和0.1%甲酸水溶液(含10 mmol/L乙酸铵)为流动相进行梯度洗脱,电喷雾负离子模式电离,多反应监测模式检测,外标法定量。对鸡蛋、鸡肉和蛋糕3种基质效应进行了试验。结果表明1μg/kg～50μg/kg范围内线性关系良好,相关系数R2>0.99。方法的检出限为0.4μg/kg,定量限为1μg/kg。在鸡蛋、鸡肉和蛋糕中分别添加1、2、5μg/kg 3个水平进行加标回收试验,回收率为82.3%～112.5%,相对标准偏差为1.2%～4.5%。该方法具有较高的灵敏度和准确度,适用于鸡蛋、鸡肉和蛋糕中氟虫腈及残留物的测定。     

分散固相萃取结合液相色谱串联质谱法检测牛可食性组织中吡喹酮残留量

目的建立分散固相萃取结合液相色谱串联质谱法检测牛肉、牛脂肪、牛肝和牛肾等可食性组织中的吡喹酮残留量的分析方法。方法取牛组织样品经50%(V:V)乙腈溶液提取,加入无水硫酸镁和氯化钠进行脱水和盐析,正己烷脱脂,高速离心分层后,取适量乙腈层溶液经0.1%(V:V)甲酸稀释后,用酸性氧化铝粉末进行样品净化并以10000r/min离心取上清液,过0.22μm滤膜后上机测定。使用反相色谱柱进行分离,流动相为0.1%甲酸和乙腈溶液,采用梯度程序进行洗脱,三重四极杆质谱进行定性定量分析。结果吡喹酮在2.5～500μg/kg范围内线性关系良好(r0.995),方法的最低检出限为1μg/kg,最低定量限为2.5μg/kg,添加回收率在60%～110%,相对标准偏差(relative standard deviation, RSD)10%。结论该方法具有较好的准确度与精密度,适用于牛可食性组织中吡喹酮残留量的测定。     

超高效液相色谱-串联质谱法测定动物源性食品中的金刚烷胺

目的建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)测定动物源性食品(鸡肉、鸡肝、鸡蛋和牛奶)中金刚烷胺的分析方法。方法样品用0.2%(V:V)甲酸乙腈溶液提取,经Oasis PRiME HLB小柱净化后用Capcell Pak C18 MGIII-H色谱柱分离,以甲醇和0.1%甲酸水溶液(V:V)作为流动相进行梯度洗脱,在多反应监测(multiple reaction monitoring,MRM)模式下进行液相色谱-串联质谱法测定,基质匹配标准溶液外标法定量。结果金刚烷胺在1.0~50.0μg/L范围内线性关系良好(r~2=0.9994)。在添加水平为1.0,5.0和20.0μg/kg时的回收率为76.3%~93.5%,相对标准偏差(relative standard deviation,RSD)在3.4%~8.6%之间,方法的检测限(limit of detection,LOD)为0.2μg/kg,定量限(limit of quantification,LOQ)为1.0μg/kg。结论该法简便、灵敏、准确,适合于动物源性食品中金刚烷胺的快速分析测定。     

固相萃取-同位素稀释超高效液相色谱-串联质谱法测定动物源性食品中24种β2-受体激动剂

目的建立固相萃取-同位素稀释超高效液相色谱/串联质谱法同时测定动物源性食品中24种β2-受体激动剂残留量的检测方法。方法样品经β-葡萄糖苷酸酶水解,过混合阳离子(MCX)固相萃取柱净化。采用乙腈和含有0.1%甲酸的水为流动相,梯度洗脱,质谱(ESI+)采用多离子检测模式(MRM)对24种β2-受体激动剂残留量进行检测。结果该方法各组分的最低定量限为0.1~0.5μg/kg,在0.1~20.0μg/kg浓度下呈现良好的线性关系,加标回收率为72.5%~109.3%。结论该方法操作简便,准确,快速,灵敏,可同时检测24种β2-受体激动剂的残留量。     

高效液相色谱-串联质谱法测定卤肉中3种β-受体激动剂残留

建立卤肉中3种β-受体激动剂(克仑特罗、莱克多巴胺、沙丁胺醇)残留检测的高效液相色谱-串联质谱方法。样品经β-盐酸葡萄糖醛甙酶/芳基硫酯酶水解,MCX固相萃取柱净化,以乙腈-0.1%甲酸溶液作为流动相洗脱,采用电喷雾离子源,多反应监测方式进行采集,外标法定量。结果表明：3种β-受体激动剂在1～100ng/mL质量浓度范围内呈现良好的线性关系,R2均大于0.99,方法检测限均为0.25μg/kg,从0.5、1μg/kg和2μg/kg添加水平检测结果可以看出,方法平均回收率为80%～120%,相对标准偏差为1.0%～10.0%。     

固相萃取-高效液相色谱-串联质谱法测定酱油中4-甲基咪唑

建立固相萃取-高效液相色谱-串联质谱/质谱法(SPE-HPLC-MS/MS)测定酱油中4-甲基咪唑的分析方法。试样经水稀释提取,LC-SCX固相萃取柱净化后,以乙腈和5mmol/L乙酸铵溶液(含0.1%甲酸,V/V)作为流动相,C18色谱柱分离,采用电喷雾离子源,正离子扫描多反应监测(MRM)模式进行检测。4-甲基咪唑在5~500μg/L浓度范围内呈良好线性关系,相关系数(r2)大于0.99,加标回收率为83.6%~95.1%,相对标准偏差为7.3%~8.2%,方法检出限为5μg/kg,定量限为10μg/kg。方法简单快速、准确灵敏,适用于酱油中4-甲基咪唑的测定。     

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