QuEChERS-高效液相色谱-串联质谱法测定苹果中丁醚脲及其代谢物残留量

目的建立基于QuEChERS-高效液相色谱-串联质谱测定苹果中的丁醚脲及其代谢物丁醚脲-脲和丁醚脲-甲酰胺残留量的方法。方法样品经乙腈提取后用PSA作为固相分散萃取剂净化除杂,以0.1%甲酸乙腈溶液和0.1%甲酸水溶液(含10 mmol/L甲酸铵)为流动相进行梯度洗脱,高效液相色谱-串联质谱法正离子多反应监测模式(MRM)测定。结果丁醚脲及其代谢物在5~100μg/L的范围内有良好的线性,相关系数(R2)0.999。定量限5μg/kg为以空白苹果为基质,在5、10、50μg/kg三个水平的加标回收率范围在78.3%~103.1%之间,精密度在2.1%~8.2%之间。结论该方法前处理快速简单,可用于对进出口的苹果中丁醚脲及其代谢物的检测。     

QuEChERS-液相色谱-串联质谱法测定茶叶中的丁醚脲

目的:建立茶叶中丁醚脲农药残留检测的液相色谱-串联质谱方法。方法:茶叶样品用乙腈提取后所得提取液经过Qu ECh ERS法净化除去杂质。采用乙腈-水(含0.1%甲酸)流动相体系进行洗脱,C_(18)色谱柱进行色谱分离,电喷雾正离子模式电离,多级反应模式监测,外标法定量。结果:采用GB/T 23205—2008《茶叶中448种农药及相关化学品残留量的测定液相色谱-串联质谱法》检测丁醚脲时回收率低的主要原因是其在前处理过程中发生了分解。采用本实验建立的方法,丁醚脲在1.0~500μg/L质量浓度范围内线性良好(r=0.999 9),定量限为0.01 mg/kg。在0.010、1.0、5.0 mg/kg三个添加量水平的平均加标回收率为83.3%~99.4%,相对标准偏差在1.87%~6.30%之间。结论:本方法操作简便,耗时较短,有效避免了前处理过程中丁醚脲分解对检测结果的影响,适用于茶叶中丁醚脲残留的定性及定量分析。     

超高效液相色谱——串联质谱法测定青梅酒中二甲基黄

建立了用超高效液相色谱-串联质谱测定青梅酒中二甲基黄的方法。该方法以乙酸乙酯提取,以0.1%甲酸-乙腈为流动相,UPLC BEH C18分离,ESI+模式质谱检测,外标法定量。二甲基黄在0.1 μg/L~4.0 μg/L浓度范围内线性关系良好,相关系数r为0.9948,检出限为3 μg/kg,定量限为10 μg/kg。青梅酒在10.0 μg/L、20.0 μg/L、100.0 μg/kg三个加标浓度下,二甲基黄的回收率为71.43%~104.9%,相对标准偏差为3.96%~7.69%。     

PRiME HLB固相萃取-高效液相色谱-串联质谱法同时快速测定鸡蛋中48种兽药残留

建立固相萃取-高效液相色谱-串联质谱同时快速测定鸡蛋中48种兽药残留的分析方法。样品采用90%乙腈水溶液提取,用PRiME HLB小柱净化浓缩后用电喷雾离子源,正负离子扫描,多反应监测模式的高效液相色谱-串联质谱法进行检测,以基质匹配曲线外标法定量。正离子采用CAPCELL PAK C18 MGⅢ-H色谱柱,流动相为0.05%甲酸乙腈和0.1%甲酸水;负离子采用ACQUITY UPLC BEH C18色谱柱,流动相为5 mmol/L乙酸铵和乙腈。结果表明,鸡蛋样品中的48种兽药残留在0.5~50 μg/kg浓度范围内线性关系良好,相关系数(r)为0.9952~1.0000。方法检出限为0.01~0.55 μg/kg,定量限为0.03~1.83 μg/kg,样品回收率在63.3%~111.4%之间,相对标准偏差小于10%(n=3)。本方法操作快速简单,重复性好,灵敏度较高,适用于鸡蛋中48种兽药残留的快速筛查检测。     

高效液相色谱-串联质谱法测定乳和乳制品中19种苯并咪唑类药物及其代谢物残留量

目的 建立高效液相色谱-串联质谱法测定乳和乳制品中19种苯并咪唑类药物及其代谢物残留量的方法。方法 样品采用水-乙腈溶液提取, 氯化钠盐析, 饱和正己烷脱脂净化直接稀释后, 经Atlantis T3 (4.6 mm×100 mm, 3 μm)色谱柱分离, 以乙腈-0.1%甲酸溶液为流动相, 采用电喷雾离子源质谱, 在正离子扫描方式下以多反应监测(multiple response monitoring, MRM)模式检测, 外标法定量。结果 19种苯并咪唑类药物及其代谢物在3个加标水平下的平均回收率为70.7%~110.0%, 相对标准偏差为2.3%~9.9%。在0.2~10 μg/L质量浓度范围内线性关系良好, 定量限为10~80 μg/kg。结论 该方法操作简便, 灵敏度高, 抗干扰能力强, 回收率和重复性良好, 适用于乳和乳制品中苯并咪唑类药物及其代谢物的测定。     

高效液相色谱–串联质谱测定动物源性食品中硝基咪唑类药物及其代谢物残留量

目的 建立高效液相色谱–电喷雾电离串联四级杆质谱测定动物源性食品中甲硝唑(MNZ)、地美硝唑(DMZ)、洛硝哒唑(RNZ)3种硝基咪唑类化合物及2种代谢物羟基甲硝唑MNZOH(甲硝唑代谢物)、1-甲基-5-硝基-2-羟甲基咪唑HMMNI(地美硝唑代谢物)残留量的检测方法。方法 样品采用乙酸乙酯提取, 甲醇和正己烷分配除脂, 再经HLB固相萃取柱净化, 采用高效液相色谱–串联质谱法在选择离子监测(MRM)正离子模式(ESI+)下检测。结果 该方法在0.1~100.0 μg/L范围内具有良好的线性关系, 相关系数r >0.99。在添加水平为0.1、0.5、10.0 μg/kg时, 方法的回收率在61.1 %~108.0 %之间, 相对标准偏差为1.9 %~6.3 % ; 定量下限(S/N=10)为0.1 μg/kg。结论 该方法适合动物源性食品中硝基咪唑类药物及其代谢物残留量的检测。     

分散固相萃取结合HPLC-MS/MS同时测定茶叶中丁醚脲及其降解产物

建立分散固相萃取(QuEChERS)—高效液相色谱—串联质谱(HPLC-MS/MS)法同时测定茶叶中丁醚脲及其降解产物残留量的方法。样品中丁醚脲及其降解产物用乙腈提取,提取液经过分散固相萃取法(QuEChERS)净化后,采用C_(18)色谱柱分离,以0.1%乙酸水溶液和乙腈为流动相,梯度洗脱,在电喷雾离子源正离子模式下采用质谱多反应监测(MRM)模式检测,外标法定量。结果表明,丁醚脲的定量限为0.01mg/kg,丁醚脲—甲酰胺的定量限为0.005mg/kg、丁醚脲—脲的定量限为0.003mg/kg。在3个浓度水平下平均回收率为62.2%~99.6%;相对标准偏差(RSD%)为1.3%~9.4%。该方法能同时对茶叶中丁醚脲及其降解产物进行定性、定量检测,方法简单、快速,准确度、灵敏度高,且减少了前处理过程中丁醚脲的分解。可同时对茶叶中丁醚脲及其降解产物进行定性、定量检测,满足残留检测的需要。     

通过式固相萃取净化-超高效液相色谱-串联质谱法快速测定禽肉中利巴韦林的残留量

建立了通过式固相萃取净化-超高效液相色谱-串联质谱法快速测定禽肉中利巴韦林残留量的方法。样品在37 ℃经酸性磷酸酯酶酶解,乙腈提取,EMR-Lipid固相萃取柱净化,以乙腈和0.1%甲酸水（含5 mmol/L甲酸铵）为流动相,经过BEH Z-HILIC色谱柱（100 mm×2.1 mm,1.7 μm）分离,经串联质谱仪,在电喷雾正离子模式下以多反应监测（MRM）模式测定,同位素内标法定量。对前处理条件、液相条件和质谱参数进行了系统的考察。该方法在0.05~5 μg/L质量浓度范围内线性关系良好,定量限（LOQ）为2.0 μg/kg。在2.0、4.0、20 μg/kg添加水平下,回收率为94.5%~112.0%,相对标准偏差（n=6）为1.4%~3.2%。该方法相比标准方法前处理简单、快速,适用于禽肉中利巴韦林残留的批量分析。     

超高效液相-串联质谱法研究银杏叶提取物提取过程中咖啡因的转移规律

目的:研究银杏叶提取物提取过程中咖啡因的转移规律,采用超高效液相色谱-串联质谱法测定咖啡因含量。方法:色谱柱为ACQUITY UPLC BEH C18(2.1 mm×50 mm,2.7 μm),流动相采用0.1%甲酸溶液和0.1%甲酸乙腈溶液梯度洗脱进行,流速0.3 mL/min,进样量5 μL,柱温30℃,运行时间5 min。质谱参数采用电喷雾离子源(ESI),检测方式采用多反应监测和正离子模式扫描,并进行定量分析。结果:通过优化检测方法,加标回收率在95.23%~102.49%之间,检出限为5 μg/kg,定量限为15 μg/kg。结论:建立的超高效液相色谱-串联质谱检测咖啡因含量方法操作简便,灵敏度高。研究发现,银杏叶中天然存在咖啡因,且不同产地银杏叶中咖啡因含量不同,可能和银杏生长的气候和地域有关系。银杏叶提取生产加工时,原料中约35%的咖啡因会转移至提取物中。     

超高效液相色谱-四极杆/静电场轨道阱高分辨率质谱法测定鸡肉中8种喹噁啉类药物及其代谢产物

目的 建立超高效液相色谱串联四极杆/静电场轨道离子阱高分辨率质谱法同步测定鸡肉中8种喹噁啉类药物及其代谢物的分析方法。方法 鸡肉样品分别经过1%甲酸乙腈提取5种喹噁啉类原药和1 mol/L盐酸溶液提取3种代谢物, 超声、振荡处理及高速离心后, 分别用多重基质吸附填料和Oasis HLB固相萃取柱净化并收集, 氮气吹干, 用0.1%甲酸-乙腈溶液定容后合并进行分析。采用Acquity UPLC BEH C18 (2.1 mm× 100 mm, 1.7 μm)色谱柱进行分离, 以0.1%甲酸水和0.1%甲酸甲醇作为流动相, 进行梯度洗脱。质谱采用平行反应监测模式下进行定性与定量分析。结果 8种化合物能够得到较好地分离, 在线性范围内线性关系良好, 相关系数均大于0.999。在1、10、100 ng/g加标水平下, 8种化合物平均回收率为76.1%~112.8%, 相对标准偏差小于15%。方法检出限和定量限分别为0.04~0.1 μg/kg和0.12~0.3 μg/kg。结论 本方法样品处理过程简便、分析时间短, 准确可靠、灵敏度高, 可用于鸡肉产品中多种喹噁啉药物的监测。     

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