四乙酰乙二胺对麦草浆 H_2O_2 漂白的活化作用

对四乙酰乙二胺（TAED）活化的麦草 Soda-AQ 浆过氧化氢漂白中的几个过程变量（TAED 与 H2O2 的摩尔比、温度、时间、NaOH 用量、过氧化氢用量）进行了研究。结果表明,TAED 对 H2O2 漂白具有显著的活化作用,TAED 与 H2O2 摩尔比 0．5、温度 70℃、漂白时间 30min、NaOH 用量 2％、过氧化氢 3％（均对绝干浆）为较佳的漂白工艺条件。在此条件下漂白,纸浆的白度增值可达 22．0％ ISO,与单纯的 H2O2漂白相比,白度提高了 14．0％ ISO。     

芦苇SP浆臭氧漂白后的过氧化氢漂白研究

研究了芦苇亚硫酸盐浆臭氧漂白后的H2O2补充漂白。芦苇未漂SP卡伯值25、白度50．2％ISO、粘度1144ml／g,经过臭氧漂白后,其卡伯值为4．8、白度达到73．0％ISO、粘度为948ml/g。后续H2O2补充漂白条件为：浆浓12％、H2O2用量2．0％、MgSO4用量0．05％、Na2SiO3用量3％、漂白温度80℃、漂白时间120min,漂后纸浆的性质为：卡伯值3．2,白度82．0％ISO,粘度894ml／g．     

废旧书刊纸脱墨浆高温H2O2漂白研究

实验主要探讨了废旧书刊纸脱墨浆高温H2O2漂白的工艺参数，找出了高温H2O2漂白的最佳工艺条件。在H2O2 3％，温度100℃，NaOH 1．1％。时间70min，Na2SiO3 3．0％，MgSO4 0.5％．（NH2CN）2 0．5％。浆浓12％的条件下，漂后浆白度达69．21％ISO，比原浆白度增加了12．48％ISO．另外，对高温H2O2漂白与常规H2O2漂白的结果进行了比较。     

马尾松低卡伯值硫酸盐浆高效H2O2漂白

研究了马尾松低卡伯值硫酸盐浆高压高温H2O2漂白,探讨了漂白过程中压力、温度、时间、H2O2用量、Na2SiO3用量以及NaOH用量对漂后纸浆白度的影响.实验结果表明,H2O2漂白在压力1.2MPa左右,温度125～130℃,时间1h左右,H2O2用量为4%～5%,Na2SiO3用量为3%,NaOH用量为1%,浆浓为10%的条件下,漂后纸浆白度可达80%ISO以上.     

马尾松硫酸盐浆高压高温H2O2漂白

研究了马尾松低卡伯值硫酸盐浆高压高温H2O2漂白,探讨了漂白过程中压力、温度、时间、H2O2用量、Na2SiO3用量以及NaOH用量对漂后纸浆白度的影响.实验结果表明,在压力1.2MPa左右,温度125～130℃,时间1h左右,H2O2用量为4%～5%,Na2SiO3用量为3%,NaOH用量为1%,浆浓为10%的条件下,漂后纸浆白度可达80%ISO以上.     

脱墨浆H2O2漂白工艺条件的优化

在浆浓为10％、温度为80℃的条件下，研究了脱墨浆H2O2漂白的几种主要影响因素。研究结果表明：脱墨浆采用H2O2漂白时，其最佳工艺条件为H202用量2％，NaOH用量1．2％，H2O2用量与NaOH用量之比为1：0．6，Na2SiO，用量4．0％，漂白时间1h，助漂剂用量0．5％，在此工艺条件下所得漂白浆白度完全能够满足配抄较高白度新闻纸的需要。     

预处理对H_2O_2漂白的影响

探讨碱法浆氧脱木素后的常压和压力H2O2漂白,着重对木聚糖酶预处理以及聚羧酸类无硅稳定剂对漂白的影响进行研究。结果表明:预处理可以提高纸浆的白度和常规H2O2漂段的可漂性;聚羧酸类无硅稳定剂可替代Na2SiO3作为H2O2漂白的稳定剂;同样条件下,压力H2O2漂白可获得更高的白度。     

四乙酰乙二胺活化过氧化氢漂白欧美杨AS-AQ浆的研究

以欧美杨AS-AQ氧漂浆为研究对象,研究四乙酰乙二胺（TAED）对过氧化氢漂白中提高漂白效果,减少漂剂用量起到的活化作用。实验结果发现,P-TAED活化体系的最佳工艺条件是：TAED与H2O2的摩尔比为0．6：1,NaOH3．0％,MgSO40．05％,Na2SiO3 3．0％,浆浓10％,温度70℃,时间90min,PH13．0。P-TAED活化体系中H2O2用量取5．0％时,一段漂白度达到78．0％ISO,比常规H2O2漂白中5．0％H2O2用量的白度要高5．6个百分点,从而节约2．0％H2O2,且不损伤纸浆的黏度。此外,与常规漂白达到相同漂白效果时,可以降低温度,缩短时间。采用OD（P-TAED）多段漂,只需2．0％H2O2就可以达到白度86．0％ISI,比对照浆节约1．0％H2O2。采用OXD（P-TAED）酶预处理多段漂的白度为85．0％ISO,与对照浆的白度接近,而H2O2用量仅为1．0％,可以节约2．0％H2O2。     

马尾松CTMP的H_2O_2漂白影响因素分析

化学预热机械浆(CTMP)在我国得到了迅速发展,H2O2漂白是化学机械浆漂白的主要方法之一,本论文主要研究了在马尾松CTM的H2O2漂白中各个工艺条件,即H2O2、NaOH、Na2SiO3和MgSO4的用量及温度、浆浓和反应时间,对漂后纸浆白度和返黄值(PC值)的影响.实验结果表明,H2O2和NaOH用量是影响纸浆白度和PC值的主要因素;Na2SiO3可以提高纸浆的白度和降低纸浆PC值;MgSO4会降低纸浆白度,但对纸浆PC值的影响较小;而浆浓、温度及反应时间对纸浆白度和PC值的影响较小.马尾松CTMP的最佳工艺条件为H2O2 4%,NaOH 3%,Na2SiO3 2%,浆浓12%,温度70℃,时间2h.在此条件下,纸浆白度达到67.0%ISO,PC值为2.23.     

桉木KP浆H_2O_2漂白的酰胺活化效果

分别从酰胺助剂的用量、漂白时间、温度、用碱量、助剂的加入方式、H2 O2 用量、助剂对残余H2 O2含量的影响等几个方面研究了酰胺助剂对兰桉KP浆H2 O2 漂白的活化效果。结果表明 ,在H2 O2 漂白时添加酰胺可以显著提高漂浆白度 ,同时能保护纸浆的粘度。当酰胺与H2 O2 的用量之比为 0 3时 ,使用 2 %H2 O2 漂白兰桉KP浆白度可达 73 42 % (ISO) ,白度增值高达 38 65 % (ISO) ,与相同条件下的单纯H2 O2 漂白段相比 ,白度提高 1 6 64%。此外 ,添加酰胺助剂还具有降低漂白温度、缩短漂白时间等优点。     

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