日本沼虾中氨基脲含量检测方法的优化

目的以农业部783号公告-1–2006方法为基础,优化高效液相色谱-串联质谱法及样品前处理方法,使其更适用于日本沼虾中不同组织中氨基脲含量的检测。方法样品经过HCl水解,2-硝基甲苯衍生,乙酸乙酯萃取后,采用高效液相色谱-串联质谱法检测氨基脲含量,内标法定量。为考察优化后方法在日本沼虾不同组织测定结果的准确性和稳定性,对不同基质样品进行标准添加实验。结果氨基脲的添加水平为1.0~120.0μg/kg时平均回收率为74.3%~113.5%,精密度小于6.3%,方法检出限为0.25μg/kg(S/N≥3),定量限为0.5μg/kg(S/N≥10)。结论虾壳中氨基脲含量最高,肌肉中含量最低;肌肉中氨基脲主要以结合态形式存在,壳中氨基脲主要以游离态形式存在。     

不同来源氨基脲在刺参体内的富集和消除规律研究

目的分析刺参中低浓度氨基脲的残留分布特征,明确不同来源引起的低浓度氨基脲的变化趋势。方法采用超高效液相色谱-串联质谱法对不同来源氨基脲在刺参(Apostichopusjaponicus)体内的富集和消除规律进行研究。结果非呋喃西林源氨基脲, 1 d后氨基脲在刺参体壁的含量为0.57μg/kg,之后含量逐渐上升,到3d时含量度达到最大值1.00μg/kg。富集实验共持续3d,按天计算平均富集速率,分别为0.57、0.24、0.19μg/(kg·d),第140 d时体壁未检出,平均消除速率为0.0073μg/(kg·d);呋喃西林源氨基脲, 1 d后体壁的含量为0.52μg/kg,之后含量逐渐上升,到3 d时,含量达到最大1.00μg/kg。富集实验共持续3 d,按天计算平均富集速率,分别为0.52、0.26、0.22μg/(kg·d),第160 d时体壁未检出,平均消除速率为0.0064μg/(kg·d)。跟踪监测至180 d时,非呋喃西林源氨基脲和呋喃西林源氨基脲在刺参体壁内均未检出,半衰期分别为1045.7 h和1224.2 h,呋喃西林源大于非呋喃西林源。内脏的富集和消除速率相对较快,但内脏中氨基脲残留量大于体壁,所以降至未检出所需时间更长。结论在投喂过呋喃西林或暴露于一定浓度氨基脲的刺参,需经较长时间净化后才能降至未检出。     

砷含量测定在蜂蜜掺假鉴别中的应用

目的建立一种通过检测蜂蜜中砷的含量来鉴别大米糖浆掺假的方法。方法检测并比较大量不同来源的大米糖浆和纯正蜂蜜中砷的含量,同时优化了蜂蜜中砷的检测方法,样品以硝酸-微波消解,电感耦合等离子体质谱(ICP-MS)测定,内标法定量。结果在0~5.0μg/L范围内线性良好,定量限为10μg/kg,10、15和30μg/kg的添加水平的回收率均在83.7%~109.6%之间,相对标准偏差小于5.9%,并确定了蜂蜜中大米糖浆的阳性判定限,砷含量在15μg/kg以上的蜂蜜为大米糖浆掺假蜂蜜。结论该方法前处理简单,结果准确度和精密度高,纯蜂蜜和大米糖浆的中砷的含量差别明显,可用于蜂蜜中大米糖浆的掺假鉴别。     

超高效液相色谱-串联质谱法检测蜂蜜中的内源性酚酸和黄酮类物质

本研究建立了超高效液相色谱-串联质谱法测定蜂蜜中18种内源性酚酸、黄酮类物质检测方法。样品经盐酸水溶液提取,HLB固相萃取柱净化,采用Acquity UPLC HSS T3(2.1*100 mm,1.8μm)色谱柱进行分离,以乙腈-10 mmol/L醋酸铵溶液为流动相进行梯度洗脱,电喷雾电离,负离子多反应监测模式检测,外标法定量。实验结果表明,所建立的方法线性范围宽,能适用于各类蜂蜜中酚酸、黄酮类物质的定量分析。各物质线性关系良好,相关系数(r2)≥0.991;各分析物检出限在20~200μg/kg之间,加标回收率范围为69.2%~94.1%,RSD为0.9%~9.5%。通过对150批次天然成熟蜂蜜、市售洋槐蜜及以不同比例(20%、40%、60%、80%)糖浆混合的洋槐蜜进行检测,发现不同蜜源蜂蜜中,酚酸、黄酮的种类与含量差异较大。其中,枣花蜜中阿魏酸平均含量最高,为550μg/kg;洋槐蜜中芹菜素平均含量最高,含量为3910μg/kg;咖啡酸在荆条蜜含量最高,为1721μg/kg;糖浆掺假蜂蜜中目标物含量明显低于真正蜂蜜。该方法前处理操作简便、分析速度快、准确度高,可用于蜂蜜中多种内源性酚酸、黄酮类物质的同时测定。该方法为通过检测不同蜜源中酚酸及黄酮类物质含量建立蜂蜜指纹图谱,提供技术参考。     

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。     

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。     

离子色谱法测定蜂蜜中松二糖含量

目的 建立离子色谱法测定蜂蜜中松二糖的检测方法,初步分析市售蜂蜜松二糖含量情况。方法 用水作为样品提取剂,以136mmol/L氢氧化钠溶液和20mmol/L无水乙酸钠溶液作为淋洗液等度洗脱,进样量20μL,流速0.7 mL/min,采用Metrosep Carb 2分离柱(250 mm×4.0 mm, 5.0μm),以安培检测器进行测定。结果 离子色谱法测定蜂蜜中松二糖相关系数为0.99955,检出限达0.02 g/100 g,定量限为0.05 g/100 g,定量和定性的相对标准偏差分别为1.62%和0.089%,加标回收率为98.3%。结论 本研究建立的检测蜂蜜中松二糖含量的方法,前处理简单、分离效果好、灵敏度高、检测结果稳定可靠,可用于蜂蜜中松二糖含量的检测。通过对84个市购蜂蜜样品中松二糖含量测定分析,可对蜂蜜中松二糖的含量测定、蜂蜜真伪鉴别及制定蜂蜜相关标准提供技术支持。     

GC-MS检测蜂蜜中双甲脒残留量的方法研究

试验通过改变提取溶剂体积和前处理步骤,建立了一种快速、节约、高效的GC-MS检测蜂蜜中双甲脒残留量方法。经验证,该方法检出限为17.2μg/kg,定量限为57.3μg/kg,在20~320 ng/mL线性范围内双甲脒及其代谢物的峰面积与浓度呈良好线性关系,相关系数达0.999以上。当加标浓度在80 ng/mL时,双甲脒回收率达到92.8%~99.1%,2,4-二甲基苯胺回收率达到84.6%~88.9%。在600μg/kg含量水平下连续测定6针,其相对标准偏差为0.816%。该方法简单可靠,适合实验室进行样品的批量处理。     

Oasis MCX柱-高效液相色谱/三重四极杆质谱联用法测定火锅底料中罂粟壳不确定度评定

目的 评定Oasis MCX柱-高效液相色谱/三重四极杆质谱联用法测定火锅底料中罂粟壳不确定度。方法 用Oasis MCX柱法做前处理,高效液相色谱/三重四极杆质谱联用法进行分析,测定火锅底料中可待因,蒂巴因,吗啡,那可丁含量,并根据建立的数学模型对各分量进行不确定度评定。结果 当火锅底料中可待因含量为43.1 μg/kg时,扩展不确定度为2.2μg/kg（k=2）;蒂巴因含量为46.3μg/kg时,扩展不确定度为1.3μg/kg（k=2）;吗啡含量为42.0μg/kg时,扩展不确定度为1.4μg/kg（k=2）;那可丁含量为48.3μg/kg时,扩展不确定度为2.1μg/kg（k=2）。结论 曲线拟合是标准不确定度的最大来源,其次为重复性实验 。     

基于UPLC-MS/MS方法定量检测日本沼虾不同组织中氨基脲含量的优化研究

目的 现有方法均为针对水产品肌肉组织中硝基呋喃类代谢物残留的检测,且测定的均为氨基脲(semicarbazide,SEM)总量,本研究在此基础上对仪器条件及样品前处理方面进行优化,使现有方法更适用于日本沼虾(Macrobrachium nipponense)不同组织部位中不同形态SEM的检测。方法 样品经过盐酸酸化水解,2-硝基苯甲醛过夜衍生,调价pH后乙酸乙酯提取后,采用UPLC MS/MS定性检测,稳定同位素内标法进行定量测定。结果 SEM在0.25~20μg/kg范围内线性关系良好,相关系数大于0.999,肌肉,头壳、背壳、头足胸、眼柄和鳃6个组织的方法检出限为0.25μg/kg(S/N≥3),定量限为0.5μg/kg(S/N≥10)。肝胰腺的方法检出限为0.5μg/kg,定量限为1.0μg/kg,相对标准偏差(RSD)≤5.20%。结论 虾壳中SEM含量最高,肌肉中含量最低,肌肉中SEM主要以游离态形式存在,虾壳中SEM主要以结合态形式存在。     

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