碱蓬活性炭的制备工艺优化及吸附性能研究

以磷酸-氯化锌为双联活化剂制备碱蓬基活性炭,通过单因素试验考察H_3PO_4-ZnCl_2质量分数、活化温度、活化时间对活性炭制备过程的影响,并利用正交试验法优化碱蓬基活性炭制备工艺条件。结果表明,最佳制备工艺条件为H_3PO_4-ZnCl_2质量分数30%、活化温度500℃、活化时间80min,该条件下碱蓬基活性炭的碘吸附值和得率分别为865.45mg/g,43.39%。     

黄麻基活性炭纤维的制备及其吸附性能

以黄麻纤维为原料,采用磷酸为活化剂制备出一系列不同的黄麻基活性炭纤维。采用正交试验法研究影响活性炭纤维得率和吸附性能的主要因素(活化剂浓度、活化温度、活化时间),确立最佳制备工艺,即在磷酸浓度为4 mol/L,活化温度为450℃,活化时间为1 h的条件下,所制得的黄麻基活性炭纤维得率为43.67%,碘吸附值为1 221.13 mg/g,亚甲基蓝吸附值为360.14 mg/g。同时用扫描电镜观察黄麻基活性炭纤维的微观形貌。     

KOH活化脱墨污泥基活性炭的制备及表征

以造纸厂脱墨污泥和木粉为原料,采用KOH活化法制备脱墨污泥基活性炭(以下简称“污泥基活性炭”),以碘吸附值为指标,探讨了污泥基活性炭的最佳制备条件;采用X射线衍射(XRD)和扫描电镜(SEM)等对污泥基活性炭的结构进行表征。结果表明,污泥基活性炭的最佳制备条件为：木粉添加量20%、炭碱比1∶1、活化温度675℃、活化时间75 min;该条件下所制备的污泥基活性炭的碘吸附值达623.44 mg/g;XRD分析表明,污泥基活性炭不规则化程度小,保存了原有的纤维结构;SEM分析表明,污泥基活性炭总体呈分散的短小棒状结构,孔呈蜂窝状致密分布,微孔比例达80.3%。将污泥基活性炭用于处理造纸厂碱抽提段漂白废水的效果显著,当添加量为4 g/L时,废水CODCr、色度和浊度的去除率分别达到63.6%、93.6%和91.6%。     

造纸废液木素制备粉状活性炭的研究

以碱法木浆废液木素为研究对象,利用磷酸作活化剂对碱木素进行炭化活化,制得粉状活性炭,优化工艺条件,得出最佳的工艺条件为:磷料比4.5∶1,活化温度500℃,活化时间10min。在此条件下制得活性炭产品的亚甲基蓝吸附值达8.6mL/0.lg活性炭得率为31.25%。进一步对所得产品的表面结构、元素组成、比表面积及孔径分布进行表征。     

稻壳基活性炭的焦磷酸活化制备及其吸附特性

以焦磷酸为活化剂制备稻壳基活性炭,并考察了其吸附特性。结果表明,制备稻壳基活性炭的最佳工艺条件为:浸渍时间3h,剂料比0.6,活化温度450℃,活化时间90min。在此条件下,稻壳基活性炭的亚甲基蓝吸附值为235.4mg/g。苯酚在稻壳基活性炭上的吸附过程符合Freundlich吸附等温线和拟二级动力学模型。热力学分析表明,该吸附过程为自发进行的多层吸附,且以化学吸附为主。     

疏水纤维素柔性凝胶材料吸附苯酚性能研究

以粉末状纤维素和丙烯酰胺为单体,过硫酸钾为引发剂,N, N-亚甲基双丙烯酰胺为交联剂,制备了纤维素柔性凝胶材料（MPCs）,经疏水改性处理后得到疏水纤维素柔性凝胶材料（T-MPCs）,并用于吸附分离溶液中的苯酚。通过改变苯酚溶液pH值、初始浓度和吸附剂添加量,研究T-MPCs吸附苯酚的影响因素和吸附机理。结果表明,T-MPCs是一种表面多孔的柔性凝胶材料,在吸附温度25 ℃、溶液pH值7.0、吸附时间360 min、初始浓度200 mg/L的条件下,T-MPCs添加量为1000 mg/L时,其对苯酚的平衡吸附量为148.9 mg/g,吸附过程符合准二级动力学模型及Freundlich等温吸附模型,具有良好的再生能力,5次循环再生后,T-MPCs吸附性能下降15.2%。     

磷酸活化脱墨渣制备中孔活性炭研究

以废纸脱墨渣(污泥)为原料,通过磷酸活化法制备中孔活性炭,以碘吸附值和亚甲基蓝吸附值为考察指标,研究了活化时间、活化温度、浸渍比及磷酸浓度等对活性炭吸附性能的影响。得到的最佳制备条件为:活化时间90 min,活化温度450℃,浸渍比1∶3.5,磷酸浓度70%。此条件下脱墨渣活性炭得率为54.57%,得到的脱墨渣活性炭碘吸附值为421.98 mg/g,亚甲基蓝吸附值为10.97 mL/g,比表面积、总孔容和中孔率分别达715.576 m~2/g、0.353 mL/g和97.45%。磷酸活化法制备的脱墨渣活性炭比表面积较大,中孔发达。红外光谱、扫描电镜及X射线衍射表征表明,脱墨渣活性炭表面含有大量羟基等多种官能团;脱墨渣活性炭的晶化程度较大,微晶不规则,孔隙结构稳固。以脱墨渣为原料采用磷酸活化技术可成功制备出中孔活性炭。     

废弃棉/亚麻混纺织物制备活性炭的性能

为实现废弃织物的综合利用,以废弃的棉／ 亚麻（50／50）混纺织物为原料,以氮气为载体,将水蒸气送入高温管式炉中进行活化制备活性炭。研究了活化温度、活化时间和水蒸气的载体流速对活性炭的比表面积、孔径分布的影响;利用废弃棉／ 亚麻活性炭的碘吸附量来表征其吸附能力,分析结构性能与吸附性能之间的关系。试验结果表明：随着活化温度、活化时间、水蒸气载体流速的增加,活性炭碘吸附量先增大后减小,而孔直径不断增大;当活化温度为800 ℃、活化时间为50min、水蒸气载体流速为240L／h时,活性炭比表面积及孔容达到最大,分别为1047.34ｍ２／g和1.25ｃｍ３／g,孔直径在18nm左右,碘吸附量为805.16mg／g;当活化温度为750 ℃,活化时间为50min,水蒸气载体流速为240L／h 时,活性炭比表面积为648.25m2／g,孔直径为4nm左右,此时碘吸附量达到最大值,为1079.39mg／g。     

木素胺化改性制备重金属吸附剂

以木素为原料,通过胺化改性制备木素基重金属吸附剂,吸附Pb2+。实验中首先将木素用琥珀酸酐进行酸酐改性,然后以对甲苯磺酰氯为催化剂与三乙烯四胺反应,得到胺化改性木素。以琥珀酸酐与木素摩尔比及反应时间为变量优化酸酐改性条件。通过测定羧基含量、红外光谱分析(FT-IR)和吸附性能分析对产物性能进行表征。结果表明,琥珀酸酐与木素摩尔比1.5∶1、反应时间1 h、温度28℃、pH值8.5~9.0时,所得酸酐改性木素中羧基含量最高,达1.98 mmol/g;FT-IR谱图分析显示木素改性成功;胺化改性木素对Pb~(2+)吸附符合拟二阶动力学模型和Freundlich模型,同时随着pH值的升高,产物吸附性能随之提高,p H值5时吸附性能降低,在p H值为5时胺化改性木素对Pb~(2+)的吸附量达到152.95 mg/g。     

油茶果壳制备活性炭的工艺研究

以氢氧化钾作为活化剂来制备油茶果壳活性炭,分别考察了活化剂浓度,料液比,活化温度,活化时间对活性炭产品碘吸附值、亚甲基蓝脱色率的影响,然后通过正交试验优化,得出最佳制备工艺为:温度700℃,料液比1:5,活化剂浓度6 mol/L,活化时间90 min,所得成品亚甲基蓝脱色率达到96.25%,脱色效果良好;碘吸附值达到1145.59 mg/g,吸附性能优良,符合商品活性炭标准。     

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