高碱度铝鞣剂生产技术

［２０］　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　高碱度铝鞣剂生产技术　　ＴｅｃｈｎｉｑｕｅｏｆＰｒｏｄｕｃｉｎｇＨｉｇｈＢａｓｉｃｉｔｙＡｌｕｍｉｎｉｕｍ栏目特约主持：李广平（天津皮革化工厂）　垂询电话：（０２２）２４３１７８０１１　制法铝鞣剂的基本成份是碱式氯化铝Ａｌ（ＯＨ）２Ｃｌ。其制法是三氯化铝用纯碱Ｎａ２ＣＯ３进行碱化反应生成碱式氯化铝。ＡｌＣｌ３·６Ｈ２Ｏ＋Ｎａ２ＣＯ３→Ａｌ（ＯＨ）２Ｃｌ＋２ＮａＣｌ＋ＣＯ２＋５Ｈ２Ｏ或直接用铝粉…     

直辊丝光机导布辊污垢的化学清洗

在丝光过程中,水中的Ｃａ＾２＋、Ｍｇ＾２＋、ＨＣＯ３＾－与布上的ＯＨ＾－生成不溶水的Ｍｇ（ＯＨ）２、ＣａＣＯ３,并附在导辊上形成钙镁垢,从而影响产品质量。采用配有缓蚀剂和渗透剂的３％氨基磺酸清洗剂对直辊丝光导布辊污垢进行清洗,其除垢速度快,除垢效果好,对设备腐蚀轻微,而且降低了劳动强度,提高了生产效率和产品质量。     

测定回收灰质量的煅烧仪工作原理及其应用

在苛化沉降物白泥（主要成分ＣａＣＯ３）转化为生石灰（主要成份ＣａＯ）的过程中,ＣａＣＯ３的含量在不断地减少。当碳酸钙含量在１５％～３０％时,说明石灰炉燃烧正常,且回收灰质量合格。利用煅烧仪可以测定回收灰中碳酸钙的含量。该文介绍了煅烧仪的工作原理及其应用。     

Ca（OH）2—NaOH—H2O2制麦草浆的研究：第Ⅲ部份：与机木浆配抄新闻纸

研究表明：在Ｃａ（ＯＨ）２－ＮａＯＨ－Ｈ２Ｏ２法制麦草浆中，当Ｃａ（ＯＨ）２和ＮａＯＨ的应用量比为５０：５０时，既保留了该法蒸煮条件温和，成浆得率高，强度大，化学药品费用低等优点，又改善了纸浆的可漂性。用ＨＡＰ三段漂（有效氯１０％，Ｈ２Ｏ２用量３％）可将该浆漂至５１％，配加１０％漂白机木浆，抄制的新闻纸可达到规定质量标准。     

CO_2传感器的研究

采用ＮＡＳＩＣＯＮ（Ｎａ离子导体）与ＢａＣＯ＿３－Ｌｉ＿２ＣＯ＿３电极相结合的方式，使新型ＣＯ＿２传感器得到发展，据观察，其响应时间以及抗水湿性能都有了提高。对ＣＯ＿２浓度在１００～５×１０￣５ｐｐｍ这样宽的范围内，５００℃时测得的电动势与能斯特方程符合得很好。该元件几乎不受共存的Ｈ＿２Ｓ１００ｐｐｍ，ＮＯ＿２１００ｐｐｍ，ＣＯ１００ｐｐｍ，ＳＯ＿２１００ｐｐｍ，Ｃ＿２Ｈ＿５ＯＨ１００ｐｐｍ，ＣＨ＿４５０００ｐｐｍ以及ＮＨ＿３２０００ｐｐｍ的影响。电极材料在２０℃高湿状态下保持８００ｈ以上，其状态仍然没有大的变化．     

硬脂酸涂覆碳酸钙填充聚丙烯的性能研究

采用廉价的硬脂酸为偶联剂，对碳酸钙进行涂覆后填充聚丙烯（ＰＰ），研究其对ＰＰ加工性能和机械性能的影响．结果表明：硬脂酸是有效的偶联剂，当用质量百分比为２％的硬脂酸涂覆ＣａＣＯ３后填充ＰＰ时，能使ＰＰ的综合性能有较大的改善；当涂覆ＣａＣＯ３的填充量为４０％（质量百分比）时，填充体系的抗冲性能为纯ＰＰ的２倍以上，而对ＰＰ本身固有的优良的抗拉伸性能影响不大，并能增加其熔体流动速率，改善加工性能．     

由工业氯化钡制备高纯度碳酸钡的研究

本文以工业ＢａＣｌ２·２Ｈ２Ｏ为原料,采用混合溶剂法除去了Ｃａ２＋、Ｓｒ２＋等主要杂质,获取了高纯度ＢａＣｌ２·２Ｈ２Ｏ。将所得高纯度ＢａＣｌ２·２Ｈ２Ｏ与ＮＨ４ＨＣＯ３反应,并经６０℃二次蒸馏水洗涤,１２０℃干燥,制备了纯度为９９．９１％高纯度ＢａＣＯ３,其中的Ｃａ２＋、Ｓｒ２＋含量低于２０ｐ     

黄酒氧化钙测定方法探讨

在国家标准ＧＢ／Ｔ１３６６２—９２《黄酒》中,氧化钙测定（化学法）原理是用草酸铵与试样中的钙生成草酸钙沉淀,然后用硫酸溶解草酸钙沉淀,最后用高锰酸钾标准溶液滴定。Ｃａ２＋＋Ｃ２Ｏ４２－→ＣａＣ２Ｏ４↓ＣａＣ２Ｏ４＋２Ｈ＋→Ｈ２Ｃ２Ｏ４＋Ｃａ２＋５Ｃ２Ｏ４２－＋２ＭｎＯ４－＋１６Ｈ＋→２Ｍｎ２＋＋１０ＣＯ２↑＋８Ｈ２Ｏ其试验步骤为：取试样２５ｍｌ于４００ｍｌ烧杯中,用５０ｍｌ左右的水进行稀释,加入３滴甲基橙指示液及２ｍｌ浓盐酸,然后加入３０ｍｌ饱和草酸铵溶液,并将溶液煮沸、搅拌。逐滴加入１＋１０氢…     

碳酸钙填料的表面改性

对不同表面活性剂改性的ＣａＣＯ３ 填料进行研究,并将其应用于硬质ＰＶＣ塑料体系．从接触角、吸水率、表面自由能、粒径分布等方面研究了改性ＣａＣＯ３ 的表面性质．结果表明,改性后的ＣａＣＯ３ 表面疏水亲油、在油中的平均团聚粒径减小．将改性ＣａＣＯ３ 以高比例（ＣａＣＯ３∶ＰＶＣ＝ ５０∶１００）填充于塑料体系,发现用表面活性剂改性的ＣａＣＯ３ 填料可显著改善塑料的加工性能和力学性能．     

亚法清净硫熏中和工艺条件的探讨

实验证实亚法糖汁精净中清汁ＳＯ２－３和Ｃａ＾２＋含量随熏强度和中和ＰＨ值升高而下降。采用中性偏码和高硫熏强度的工艺条件，能降低清汁中ＣａＳＯ３的含量，增加ＣａＳＯ３的沉淀量，显著减少青汁中ＳＯ＾－３和Ｃａ２＋的含量，有效提高清汁的品质。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.