面粉中氨基脲含量的测定及偶氮甲酰胺和氨基脲转化规律的研究

目的建立超高效液相色谱-串联质谱法测定面制品中的氨基脲含量,并研究偶氮甲酰胺添加水平对面粉中氨基脲含量的影响及两者的转化条件。方法样品经盐酸水解、邻硝基苯甲醛衍生、HLB小柱净化及乙酸乙酯提取;质谱以电喷雾电离源正离子模式扫描监测,用带有同位素内标的衍生物~(15)N_2~(13)C-SEM-NBA定量检测目标氨基脲衍生物。结果氨基脲在0.5~100μg/kg范围内呈良好线性关系,相关系数为0.9995,检出限为0.5μg/kg,加标回收率在85.1%~114.6%之间,相对标准偏差为3.2%~6.9%。市售10份面制品中氨基脲的阳性检出率为41.7%。氨基脲是偶氮甲酰胺在湿热的条件下生成的,并且同一种面制品中外部氨基脲含量比内部含量大。结论本方法快速、准确且灵敏度高,可适用于面制品中氨基脲的定量分析。     

固相萃取-超高效液相色谱-串联质谱法检测面粉及面制品中的氨基脲

建立面粉及面制品中氨基脲的超高效液相色谱-三重四级杆串联质谱方法。方法 在样品中加入同位素取代的氨基脲,以0.2 mol/L HCl提取后,与衍生剂邻硝基苯甲醛反应。衍生产物在中性条件下经HLB柱净化,乙酸乙酯洗脱,吹干复溶后,以超高效液相色谱的C₁₈柱(50 mm×2.1 mm,1.7 μm)分离,质谱法检测。以保留时间与质谱离子对定性,内标法定量。结果 氨基脲在0.5～100 μg/kg范围内呈线性相关。方法精密度良好(RSD<20%,n=6),回收率在60%～120%之间,定量限为0.5 μg/kg(S/N=10)。结论 本方法特异性强,灵敏度高,适合于面粉及面制品中的氨基脲检测。     

深圳市面粉与面制品中偶氮甲酰胺及其转化产物膳食暴露评估

目的了解深圳市居民面粉与面制品中偶氮甲酰胺及其分解转化产物联二脲、氨基脲的含量水平,获得深圳市致癌致畸物氨基脲的居民膳食暴露水平。方法 2016年在深圳市超市、批发市场、农贸市场等共采集500份面粉及面制品,监测偶氮甲酰胺及其分解转化产物联二脲、氨基脲的含量。并结合深圳市居民膳食调查食物消费量计算深圳市居民面粉和面制品中氨基脲的暴露量。结果所采集的500份样品中:偶氮甲酰胺、联二脲、氨基脲的检出率分别为4.60%、25.8%、18.6%,含量范围为0.500～93.4 mg/kg、10.0～13900μg/kg、0.250～1100μg/kg;氨基脲的一般水平暴露量与高水平暴露量分别为0.005μg/kg-bw/d与0.248μg/kg-bw/d。结论面粉及面制品中的氨基脲暴露已超过水产品中的暴露,应慎重使用偶氮甲酰胺作为食品添加剂在面粉及面制品中使用,同时加强对面粉及面制品中氨基脲的监测。     

液相色谱-串联质谱负离子模式测定鸡肉中磺胺硝苯的残留

建立高效液相色谱-串联质谱测定鸡肉中磺胺硝苯残留的方法。样品经过甲酸-乙酸乙酯(2∶98,V/V)提取,正己烷脱脂,液-液分配净化后,C18柱分离,甲醇、5 mmol/L乙酸铵为流动相梯度洗脱,采用负离子扫描多反应监测(multiple reaction monitoring,MRM)模式下液质联用仪进行定性和定量分析。在2.0~100.0μg/L质量浓度范围内,线性相关系数大于0.99,方法的检出限和定量限分别为0.5μg/kg和2.0μg/kg,在2.0、5.0、10.0μg/kg添加量的回收率为76.0%~83.4%,相对标准偏差(relative standard deviation,RSD)小于8.7%。该方法简便快捷,可用于鸡肉中磺胺硝苯残留量测定。     

超高效液相色谱-串联质谱法测定纯牛奶中喹乙醇及其代谢物

目的建立可靠的前处理方法 ,采用超高效液相色谱-串联质谱法检测纯牛奶中喹乙醇及其代谢物3-甲基-喹噁啉-2-羧酸(MQCA)。方法样品经盐酸水解,乙腈-乙酸乙酯(1∶1,V/V)提取,分析了直接浓缩及分别经PAX、PEP固相萃取小柱净化、富集的结果 ;以乙腈-0.05%氨水为流动相,经Inertsil ODS-3色谱柱(2.1 mm×100 mm,3μm)分离,采用多反应监测正离子模式进行定性及定量分析。结果直接浓缩具有较好的回收率,喹乙醇的方法检出限为0.06μg/kg,方法定量限为0.20μg/kg,在0.20、1.00、5.00μg/kg 3个加标水平下回收率分别为69.8%、111%、97.4%;MQCA的方法检出限为0.02μg/kg,方法定量限为0.10μg/kg,在0.10、1.00、3.00μg/kg 3个加标水平下回收率分别为75.8%、112%、117%。结论该检测方法适用于纯牛奶中喹乙醇及其代谢物残留的检测。     

高效液相色谱-串联质谱法测定鸡肉中的金刚烷胺

建立高效液相色谱-串联三重四极杆质谱法(High performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS)测定鸡肉中金刚烷胺的分析方法。金刚烷胺用甲醇-1%三氯乙酸(50︰50, V/V)提取,提取液经SCX柱净化,以乙腈和0.1%甲酸水溶液溶液为流动相,经Zorbax SB C_(18) (50 mm×2.1 mm×1.8μm)柱,进行梯度洗脱分离,采用ESI正模式电离,多反应监测(MRM)模式进行检测,以保留时间和定性离子对的相对丰度比定性,外标法定量。金刚烷胺的检出限(LOD)和定量限(LOQ)分别为0.5μg/kg和1.0μg/kg,在0.5～50μg/kg浓度范围内,线性关系良好(R~20.999),在0.5, 1.0和2.0μg/kg加标水平下加标回收率为85.70%～115.91%,相对标准偏差为2.51%～14.74%(n=6)。该方法操作简单、重现性好、背景噪音低、具有较高的灵敏度和选择性。     

衍生—超高效液相色谱串联质谱法测定面包糕点中的偶氮二甲酰胺

运用超高效液相色谱-串联质谱法测定面包糕点中的偶氮二甲酰胺。样品使用盐酸水解并脱蛋白,再经高温处理后,转成氨基脲,在酸性条件下用2-硝基苯甲醛衍生化,用OASIS HLB固相萃取柱净化,采用Acquity UPLC BEH C18柱分离,以乙腈和0.1%(v/v)的甲酸水溶液为流动相进行梯度洗脱,采用正离子(ESI+)、多反应监测(MRM)模式进行定性,外标法定量。结果表明:该方法的偶氮二甲酰胺检出限为0.1μg/kg,线性范围为1~100μg/L,相关系数R=0.9993,回收率为82.31%~94.39%,相关标准偏差(RSD)5%。该方法准确方便,灵敏度高,可实现面包糕点中偶氮二甲酰胺的测定。     

免疫亲和柱净化-高效液相色谱柱后光化学衍生- 荧光检测器检测食品中黄曲霉毒素

目的建立一种免疫亲和固相萃取柱净化-高效液相色谱柱后光化学衍生-荧光检测器同时测定食品中黄曲霉毒素B_1、B_2、G_1和G_2的方法。方法以甲醇-水(70:30,V:V)为提取溶剂,采用高速均质提取,并经过黄曲霉毒素免疫亲和柱净化。结果经月旭公司Welch Ultimate~XB-C_(18)色谱柱(250 mm×4.6 mm,5μm)分离后使用光化学衍生器进行柱后衍生,并采用带荧光检测器的高效液相色谱仪检测,流动相为甲醇/水(45:55,V:V)。黄曲霉毒素B_1、B_2、G_1和G_2线性范围在0.3~50.0μg/L之间,线性相关系数均大于0.999,B_1、B_2、G_1和G_2检出限分别为0.15μg/kg、0.05μg/kg、0.15μg/kg、0.05μg/kg。在3个加标浓度下大米、花生和瓜子等试样的回收率在80.7%~92.6%之间;相对标准偏差(RSD)在2.04~3.87%之间。结论该方法的灵敏度、准确度和精密度均符合黄曲霉毒素的检测技术要求,且简便快速,适用于食品中黄曲霉毒素B_1,B_2,G_1和G_2的准确测定。     

液液萃取-HPLC法测定食品中黄曲霉毒素B_1

建立一种液液萃取净化,结合柱后碘衍生-高效液相色谱检测食品中黄曲霉毒素B1的新方法。食品中黄曲霉毒素B1采用乙腈-水(85︰15, V/V)混合溶液提取,加入蛋白沉淀剂和正己烷除去蛋白质及脂溶性杂质,经三氯甲烷萃取净化、浓缩及定容后用柱后碘衍生-高效液相色谱荧光检测器进行检测。结果表明,在0.1～50.0 ng/mL浓度范围内,线性关系良好,拟合系数为0.999 97,在3倍信噪比下计算方法检出限为0.02μg/kg;分别对多种样品进行低(0.4μg/kg)、中(4.0μg/kg)、高(40μg/kg)加标回收率试验,回收率范围为75.9%～94.7%,相对标准偏差(RSD, n=6)为0.1%～5.4%。该方法分析速度快,准确度高,重复性好,适用于食品中黄曲霉毒素B1的检测。     

超高效液相色谱-串联质谱法测定竹笋中百草枯的残留

目的运用超高效液相色谱-串联质谱联用技术,建立竹笋中百草枯残留的检测方法。方法样品用甲醇-0.1 mol/L盐酸溶液(1∶1,V/V)提取后,经Oasis WCX固相萃取柱(60 mg/3 ml)净化,采用UPLC BEH HILIC色谱柱(100 mm×2.1 mm,1.7μm)分离,正离子多反应监测模式监测,外标法定量。结果百草枯在10~500μg/L范围内具有良好线性关系,相关系数为0.998 2,检出限为2μg/kg,定量限为5μg/kg。进行5、50和200μg/kg三个浓度的样品加标试验,回收率为82.2%~104.8%,相对标准偏差为8.3%~10.9%。结论该方法简便、灵敏、准确,适合于竹笋中百草枯的检测。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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