液相色谱串联质谱法测定烟用香精香料中的亚硝胺

建立了液相色谱串联质谱法(LC-MS/MS)测定烟用香精及料液中N-亚硝基去甲基烟碱(NNN)、N-亚硝基假木贼碱(NAB)、N-亚硝基新烟草碱(NAT)和4-(N-甲基-N-亚硝胺)-1-(3-吡啶基)-丁酮(NNK)4种烟草特有亚硝胺(TSNAs)的方法。样品采用含0.1 mol/L的醋酸铵甲醇水溶液溶解提取,在C18色谱柱上采用梯度洗脱分离目标物和干扰物,电喷雾正离子模式下,多反应检测模式测定。结果表明,4种TSNAs的检测限(S/N=3)和定量限(S/N=10)分别为0.4~1.6 ng/g和1.4~4.8 ng/g,标准工作液在1~50 ng/L的范围内线性良好,相关系数均大于0.9995,高中低三个浓度水平的加标回收率在93.5%~105.9%之间,6次重复实验的RSD范围为1.8%~4.7%,均小于5%。使用该方法分析测定了8个市售烟用香精香料样品,其中3个样品检测到TSNAs。该方法准确、灵敏,适用于烟用香精及料液样品中TSNAs的分析检测。     

UPLC-MS/MS法同时测定烟叶中的TSNAs

为快速准确测定烟叶中的烟草特有亚硝胺(TSNAs),优化改进了LC-MS/MS法中样品的前处理条件,建立了测定烟叶中TSNAs的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。结果表明:1用乙酸乙酯萃取代替固相萃取对TSNAs进行纯化,操作快速准确,更适合大批量样品的分析;2N-亚硝基降烟碱(NNN)、4-(N-甲基-N-亚硝基氨基)-1-(3-吡啶基)-1-丁酮(NNK)、N-亚硝基新烟草碱(NAT)、N-亚硝基假木贼碱(NAB)的定量限分别为4.22、2.38、1.29和0.72 ng/g,加标回收率在87.7%~107.0%之间。     

无烟气烟草制品中TSNAs的分析研究

用100 mmol/L乙酸铵溶液萃取样品后,用0.22μm水相针式过滤器过滤,采用液相色谱-电喷雾串联质谱(LC-ESI MS/MS)测定烟草特有N-亚硝胺,建立了无烟气烟草制品中4种烟草特有N-亚硝胺(TSNAs)的同时测定方法。利用建立的方法测定了72个不同品牌种类的无烟气烟草制品中TSNAs的含量。结果表明,N-亚硝基降烟碱(NNN)、4-(亚硝基甲氨基)-1-(3-吡啶基)-1-丁酮(NNK)、N-亚硝基新烟草碱(NAT)和N-亚硝基假木贼碱(NAB)的检出限分别是0.03、0.08、0.03和0.02 ng/mL,回收率在93.17%-105.25%之间,精密度在2.03%-4.80%之间。方法的检测限低,特异性好,适合于无烟气烟草制品中TSNAs的检测。实验发现不同品牌的无烟气烟草制品TSNAs的含量差别较大,TSNAs的总含量范围从0.54μg/g到31.91μg/g,相差59倍,平均含量为5.06μg/g。     

四氮杂杯[2]芳烃[2]三嗪键合硅胶固相萃取/HPLC-MS/MS法测定家兔血浆中的TSNAs

为了准确测定家兔血浆中的烟草特有N-亚硝胺(TSNAs),制备了四氮杂杯[2]芳烃[2]三嗪键合硅胶(NCS)固相萃取柱,并通过对NCS固相萃取、色谱及质谱条件的优化,建立了测定家兔血浆中的N-亚硝基降烟碱(NNN)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇(NNAL)、N-亚硝基新烟草碱(NAT)和N-亚硝基假木贼碱(NAB)5种TSNAs的NCS固相萃取/HPLC-MS/MS方法.结果表明:NCS固相萃取柱对家兔血浆中5种TSNAs的萃取效率优于商品化的C18固相萃取柱;5种TSNAs的检测限为0.0092～0.0590 ng/mL,回收率和相对标准偏差(RSD)分别为90.1％～113.3％和0.95％～7.22％.该方法简单、准确,适合于家兔血浆中TSNAs的检测.     

啤酒和腊肠中N,N-二甲基亚硝胺的测定

目的建立气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)测定啤酒和腊肠中N,N-二甲基亚硝胺的方法。方法试样经二氯甲烷超声提取、离心,SILICA/PSA玻璃柱净化后气相色谱/质谱仪直接测定,D6-N,N-二甲基亚硝胺内标法定量。结果加标回收率范围为66.9%~103.4%,相对标准偏差(RSD)在2.5%~7.7%。将该方法用于实际样品分析,30份啤酒中均未检出N,N-二甲基亚硝胺,8份腊肠样品中检出2份阳性样品,含量均低于肉制品中N,N-二甲基亚硝胺限量值3.0μg/kg。结论此方法简便快速,灵敏度较高,可以用于啤酒和腊肠中N,N-二甲基亚硝胺的准确定量。     

国外口含型无烟气烟草制品总烟碱、游离烟碱和烟草特有亚硝胺含量分析

采用CORESTA推荐方法测定了65种国外口含型无烟气烟草制品样品的含水率、烟碱、pH、游离烟碱和4种烟草特有亚硝胺(TSNAs).结果表明,口含型无烟气烟草制品的各项化学指标差异显著:含水率为12.07％ ～55.58％;pH为5.55～8.98;以湿重计,烟碱含量为5.41 ～27.68 mg/g,释放游离烟碱含量为0.63 ～ 10.46 mg/g,游离烟碱释放率为7.8％～72.3％;N-亚硝基降烟碱(NNN)为0.31～17.00 μg/g,4-(N-亚硝基甲胺基)-1-(3-吡啶基)-1-丁酮(NNK)为0.07～6.00μg,/g,N-亚硝基新烟草碱(NAT)为0.11 ～6.51 μg/g,N-亚硝基假木贼碱(NAB)为0.01 ～2.54μg/g,同一样品中4种TSNAs总含量为0.54～31.91μg/g.     

氢氧化钡处理-活性炭柱固相萃取/GC-MS/MS检测腌制蔬菜中7种挥发性N-亚硝胺

建立氢氧化钡处理,活性炭柱固相萃取,气相色谱-串联质谱法(GC-MS/MS)检测腌制蔬菜中挥发性N-亚硝胺的新方法。将10 g腌制蔬菜样品加入N-二甲基亚硝胺-d6和N-二丙基亚硝胺-d14内标于50 mL离心管中,经80℃密闭处理1h,离心分离,活性炭柱固相萃取,以DB-1701柱(30 m×0.25 mm×0.25μm)气相色谱分离,串联质谱多重反应监测模式进行检测。结果表明,本法可实现对批量腌制蔬菜样本中7种N-亚硝胺的检测,其中N-二丙基亚硝胺(NDPA)的检出限和定量限分别≤0.08 ng/g和≤0.2 ng/g,N-二甲基亚硝胺(NDMA)等其它6种N-亚硝胺检出限和定量限分别≤0.04 ng/g和≤0.1 ng/g;考察质量浓度范围内(1～100 ng/mL),线性良好,R2≥0.9993;0.1,1.0和5.0 ng/g三水平的加标回收率为82.1%～125.6%,相对标准偏差为0.10%～11.8%。对超市腌制蔬菜的抽样(n=46)监测表明,NDMA、N-亚硝基吗啉(NMOR)和N-亚硝基吡咯烷(NPYR)检出率为100%,N-二乙基亚硝胺(NDEA)、NDPA、N-亚硝基哌啶(NPIP)的检出率为71%～88%,N-甲乙基亚硝胺(NMEA)未检出;除NPYR含量较高,最高值为4.71 ng/g外,其它N-亚硝胺含量均在1 ng/g以下;腌制蔬菜中N-亚硝胺处于较安全水平。     

吹扫捕集-气相色谱-质谱法测定啤酒中8种亚硝胺类化合物

目的建立吹扫捕集-气相色谱-质谱法测定啤酒中8种亚硝胺类化合物的含量。方法啤酒通过吹扫捕集并经毛细管色谱柱分离,采用气相色谱-质谱法检测,以内标法定量。结果 8种亚硝胺类化合物(包括N-亚硝基二甲胺、N-亚硝基甲乙胺、N-亚硝基二乙胺、N-亚硝基二丙胺、N-亚硝基吡咯烷、N-亚硝基哌啶、N-亚硝基二丁胺和N-亚硝基二苯胺)在0.5~100.0μg/L的线性范围内呈现较好的线性关系,相关系数r均大于0.99。方法的检出限为0.20~0.35μg/L,平均回收率在78.1%~95.7%之间,相对标准偏差在2.5%~9.8%之间。结论该方法操作简单快捷,灵敏度和准确度均较高,可满足啤酒8种亚硝胺类化合物的检测。     

氢氧化钡处理-二氯甲烷萃取/GC-MS/MS检测几种水产品和加工肉制品中的7种N-亚硝胺

建立了氢氧化钡处理结合二氯甲烷萃取进行样品处理,气相色谱-串联质谱法检测几种水产品和加工肉制品中7种N-亚硝胺的新方法。以N-亚硝基二甲胺-d6、N-亚硝基二正丙胺-d14和N-亚硝基吡咯烷-d8为内标,10 g样品于50 mL离心管中经氢氧化钡溶液一步处理,离心后上清液再经二氯甲烷一次萃取,旋蒸浓缩至5 mL,氮吹至1 mL,DB-WAXUI柱(30 m×250 μm×0. 25 μm)进行色谱分离,多反应监测(MRM)模式进行质谱检测。该方法样品处理简便易行,7种N-亚硝胺在1~100 ng/mL浓度范围内线性良好(R2 > 0. 999);检出限为0.08~0.23 μg/kg,定量限为0.25~0.76 μg/kg;添加回收率为71.6%~133.8%,RSD为2.04%~17.1%。对市售9个鱼虾和8个加工肉制品的实际检测显示,N-亚硝基二甲胺的含量均在安全范围内。     

GC-FID法同时测定腌制鱼干中9种N-亚硝胺类化合物

在气相色谱-氢火焰检测器的基础上建立了同时测定腌制鱼干中9种N-亚硝胺类化合物的方法。采用碱液加热处理结合二氯甲烷萃取的方法提取腌制鱼干的N-亚硝胺,经棷壳活性炭净化,C₁₈固相萃取(SPE,Solid Phase extraction)小柱富集,样液用DB-WAXETR极性柱(30 m×0.25 mm,0.25 μm)进行色谱分离,柱温采用程序升温。结果显示:该方法下的9种N-亚硝胺类化合物在0.05~5 μg/mL浓度范围内线性良好(R2＞0. 999);检出限和定量限范围分别为0.05~0.29 μg/mL和0.18~0.95 μg/mL;回收率和RSD分别为76.8%~129.5%和2.29%~15.5%。对市售的50种腌制鱼干进行检测,N-亚硝基二乙胺(NDEA,N-nitrosodiethylamine)、N-亚硝基哌啶(NDIP,N-Nitrosopiperidine)N-亚硝基吡咯烷(NPYR,N-Nitrosopyrrolidine)检出率分别达到20%、20%、24%,只有一种样品的N-亚硝基二甲胺(NDMA,N-nitrosodimethylamine)超过国标限量规定(4 μg/kg)。     

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.