氯丙醇检测方法研究进展

氯丙醇类化合物是国际公认的食品污染物,包括3-氯-1,2-丙二醇(3-MCPD)、2-氯-1,3-丙二醇(2-MCPD)以及双氯取代的1,3-二氯-2-丙醇(1,3-DCP)和2,3-二氯-1-丙醇(2,3-DCP)。文章综述了国内外氯丙醇检测方法的研究进展,包括气相色谱(GC)法、气质联用(GC/MS)法、气相色谱双串联质谱(GC/MS/MS)联用法以及其它新的检测方法。     

沉降——分离法除去氢氧化镁中的氯

研究了絮凝剂法及控制反应温度法两种沉降——分离方法除去水氯镁石-氢氧化钠法制备氢氧化镁中的氯。     

调味品中氯丙醇的检测技术进展

氯丙醇类化合物包括3-氯-1,-丙二醇(3-MCPD)、2-氯-1,-丙二醇(2-MCPD)以及双氯取代的1,-二氯-2-丙醇(1,-DCP)和2,-二氯-1-丙醇(2,-DCP)是国际公认的食品污染物之一.就调味品中的氯丙醇检测新技术进行综述,包括气质联用(GC/MS)法、毛细管电泳检测法(CE)以及分子印记技术(MIT).     

我国市售水解蛋白氯丙醇污染状况研究

采用基质固相分散萃取法(MSPD)进行样品的净化,以稳定性同位素稀释技术结合气相-质谱法(GC-MS)的内标法定量测定氯丙醇,初步调查了我国市售水解蛋白(HVP)氯丙醇的污染水平。发现酸水解HVP产品氯丙醇污染严重,氯丙醇的典型代表3-氯-1,2-丙二醇(3-MCPD)的几何均数达到6.04mg/kg(以液体计),70%的样品3-MCPD含量超过10mg/kg。     

几种市售婴幼儿配方奶粉中氯丙醇酯的定量检测及风险评估

目的对几种市售婴幼儿配方奶粉中2种氯丙醇酯进行定量检测并开展人体健康风险暴露评估。方法奶粉样品提取脂肪后,经碱水解,以硅藻土固相萃取法净化,样液经衍生后采用气相色谱/质谱联用法(gas chromatography/mass spectrometry, GC/MS)检测,以稳定性同位素内标法对3-氯-1,2-丙二醇酯和2-氯-1,3-丙二醇酯进行定量。结果奶粉中3-氯-1,2-丙二醇酯和2-氯-1,3-丙二醇酯的检出率分别为87.5%和62.5%,平均值分别为0.058 mg/kg和0.022 mg/kg。低月龄婴幼儿氯丙醇酯暴露风险较高,超出每日耐受摄入量(tolerable daily intake, TDI)[0.8μg/(kg·d)]。结论婴幼儿配方奶粉中氯丙醇酯污染问题应高度关注,尽快制定限量标准,以降低氯丙醇酯对婴幼儿造成的健康风险。     

一氯均三嗪-β-环糊精包合驱蚊剂的应用

用反应性环糊精一氯均三嗪-β-环糊精（MCT-β-CD）包合驱蚊剂DEET，得到一氯均三嗪-β-环糊精包合物，以此产物作为驱蚊整理剂处理纤维素织物。研究了该包含物以不同工艺（浸渍法、浸轧法和冷轧堆法）整理织物的效果。研究表明，冷轧堆法效果很差，不宜采用。通过改变包合物的用量、催化剂的种类和用量、反应温度和时间等因素，得到浸轧法和浸渍法中包合物与纤维素键合反应的最佳处理工艺。     

4-氯酚废水Fenton氧化反应动力学研究

采用Fenton氧化技术对4-氯酚(4-CP)废水进行了氧化处理。研究结果表明:Fenton氧化对4-氯酚的去除效果非常明显,可在短时间内将4-氯酚降解成低分子有机物。根据Fenton氧化废水中污染物时发生化学反应的特性,利用半衰期法探讨了4-氯酚降解的反应级数,最终确定其在Fenton体系中氧化降解的表观反应级数为2.5。通过建立4-氯酚Fenton氧化降解的动力学数学模型,最终得出4-氯酚降解的动力学方程,反应动力学方程可表示为:r=k C1.9691C0.5309Fenton     

低含量3-氯-1,2-丙二醇的水解植物蛋白生产工艺优化

研究了在低酸、低温条件下植物蛋白的优化水解工艺,旨在降低水解蛋白中的氯丙醇类物质。研究确定,在95℃左右,固液比1∶5,盐酸浓度4mol/L,水解18h,所得水解蛋白中3-氯-1,2-丙二醇含量为1.25mg/kg,仅是常规酸法的5%。进一步进行碱中和与减压浓缩处理,可使3-氯-丙二醇残留大幅降低。     

同位素稀释GC-MS/MS法测定火锅添加剂中3种氯丙醇

采用同位素内标法,建立气相色谱-三重串联四极杆质谱测定火锅添加剂产品中3种氯丙醇的分析方法。样品加入氯丙醇的同位素内标,采用改良层析柱法(玻璃注射器-真空抽气系统)进行净化,正己烷-乙醚(1:1,V/V)进行提取,固相萃取法浓缩和富集,三氟乙酸酐衍生,以HP-5 ms毛细管柱分离,串联四级杆质谱多反应监测模式检测,内标法定量。结果表明:采用本文的优化条件,用2种同位素内标(1,3-二氯-2-丙醇-d5和3-氯-1,2-丙二醇-d5)校正,可准确测定火锅添加剂产品中3种氯丙醇含量。在50~1000μg/L的范围内,方法线性良好,相关系数均可达0.999以上,方法回收率在82.5~104.0%之间,RSD小于5%。本方法灵敏、定量准确、衍生化试剂价廉易得,适用于火锅添加剂中3种氯丙醇的测定。     

杭州市0～3岁婴幼儿配方乳粉中3-氯丙醇酯暴露风险评估

目的结合2017—2019年杭州市市售婴幼儿配方乳粉(以下简称乳粉)脂肪酸氯丙醇酯(以下简称氯丙醇酯)污染水平及0～3岁婴幼儿每日乳粉消费量,评估0～3岁婴幼儿人群通过乳粉摄入3-氯丙醇酯的暴露风险。方法采用气相色谱-串联质谱法测定乳粉中3-氯丙醇酯及2-氯丙醇酯(分别以3-氯丙醇和2-氯丙醇计)含量;结合我国婴幼儿喂养指南推荐的各年龄段每日乳粉消费量,采用点评估法对目标人群3-氯丙醇酯暴露风险进行评价。结果杭州市市售乳粉样品中氯丙醇酯污染普遍存在;不同月龄婴幼儿每日通过乳粉摄入3-氯丙醇酯的中位数暴露水平在0.46～2.50μg/kg BW之间,占每日可耐受摄入量(TDI,2μg/kg BW)的23.0%～125.0%;3-氯丙醇酯的第97.5百分位数(P97.5)膳食暴露量在0.87～4.30μg/kg BW之间,占TDI的43.5%～215.0%,其中0～6月龄婴儿的P97.5暴露水平均高于TDI,存在较高健康风险。结论杭州市0～3岁婴幼儿通过乳粉摄入3-氯丙醇酯的暴露存在健康风险,对于P97.5目标人群,3-氯丙醇酯的暴露水平明显偏高,存在较高风险。     

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