活性和酸性染料废水的改性腈纶脱色

采用三乙烯四胺(TETA)对腈纶纤维进行改性,探究了吸附温度、pH值和氯化钠对改性腈纶吸附活性红B-3BF和酸性红B吸附速率的影响,分析了改性腈纶对活性红B-3BF和酸性红B的吸附热力学,并对吸附热力学曲线进行拟合。研究结果表明,三乙烯四胺改性腈纶纤维在常温条件下可较快地吸附阴离子染料,酸性越强吸附速率越快、吸附量越高;三乙烯四胺改性腈纶对阴离子染料的吸附符合Langmuir+Nernst模型,说明三乙烯四胺改性腈纶与阴离子染料之间存在离子键、氢键和范德华力等多种结合方式;三乙烯四胺改性腈纶连续6次吸附1 g/L的活性红B-3BF后,1 kg纤维上染料吸附量达到700 g以上,说明改性腈纶对阴离子染料有较强的吸附能力。     

芳香醛壳聚糖树脂的制备及对活性红染料的吸附动力学研究

以壳聚糖和芳香醛为原料,经缩合制得中间产物希夫碱,再以环氧氯丙烷为交联剂合成壳聚糖螯合树脂。用紫外/可见分光光度计测定,在相同时间内、不同壳聚糖改性产物对活性红染料吸附动力学研究。结果表明:合成的三种螯合树脂中,水杨醛螯合树脂对活性红染料在最初5min吸附较快,而苯甲醛螯合树脂对活性红染料的吸附效果更好。     

芳香醛壳聚糖树脂的制备及对活性红染举的吸附动力学研究

以壳聚糖和芳香醛为原料,经缩合制得中间产物希夫碱,再以环氧氯丙烷为交联剂合成壳聚糖螯合树脂。用紫外／可见分光光度计测定,在相同时间内、不同壳聚糖改性产物对活性红染料吸附动力学研究。结果表明：合成的三种螯合树脂中,水杨醛螫合树脂对活性红染料在最初5min吸附较快,而苯甲醛螯合树脂对活性红染料的吸附效果更好。     

端氨基改性SBA-3对酸性橙Ⅱ染料吸附脱色研究

利用四乙烯基五胺改性介孔材料SBA-3,提高介孔材料对酸性橙Ⅱ染料的吸附能力。研究不同条件下功能化SBA-3介孔材料对酸性橙Ⅱ染料的吸附能力,主要考察吸附剂用量、溶液pH值对酸性橙Ⅱ吸附效果。     

选择性氧化壳聚糖硅衍生物改性羊毛织物的染色

采用高碘酸钠氧化壳聚糖制备选择性氧化壳聚糖,以硅烷偶联剂KH550为交联剂,处理经氧等离子体刻蚀的羊毛织物,研究改性羊毛的染色性能。结果表明:改性羊毛织物的可染性提高,因为氧化壳聚糖硅衍生物与羊毛之间发生了共价交联,在纤维表面引入了—OH、—NH2、—COOH等活性基,与染料分子之间的作用增强。另外,酸性条件下预处理,硅烷偶联剂KH550水解缩合,在氧等离子体刻蚀羊毛表面形成一层薄膜,增大纤维的表面积,也能有效促进染料的上染。在所研究的4种染料中,当弱酸性红B和活性黑KN-B染色温度为70℃,酸性大红G和活性红M-3B染色温度为50℃,酸性大红G和弱酸性红B的染液pH分别为1.81和2.56,活性黑KN-B和活性红M3B在中性条件下染色,改性羊毛表面可获得较高的K/S值,同时染色牢度也获得一定程度的改善。     

制革固体废弃物对皮革染料的吸附等温线和动力学研究

表明了工业植鞣革和铬鞣革固体废物具有较强的吸附能力,可以经济有效的地去除制革废水中的染料。废水取自皮革湿整理工序,分析了两种皮革废物(铬鞣革和植鞣革)吸附过程的pH值以及染料废水的浓度变化范围。在最佳的吸附pH(2~3)下,得到铬鞣革屑对酸性黄194染料、酸性红357染料和酸性黑210染料的吸附等温线和吸附动力学。酸性黄194染料、酸性红357染料和酸性黑210染料的吸附等温线为C1、H2和H3形,分别符合Henry、Langmuir和BET吸附模型。三种染料的动力学均符合Elovich模型,表明吸附过程为化学吸附。对酸性黄194染料的吸附分别用拟一级动力学和拟二级动力学方程进行拟合,酸性红357染料用拟二级动力学方程进行拟合。此外,酸性黄194染料的吸附受边界层扩散的影响,而酸性红357染料和酸性黑210染料的吸附受到颗粒内扩散的影响。     

壳聚糖-氨基磺酸硅杂化体系处理的羊毛织物染色性能

采用溶胶-凝胶法制备壳聚糖-氨基磺酸硅杂化体系,并对羊毛进行表面处理。分别选用酸性大红G和弱酸性红B对处理羊毛织物进行染色,研究了不同染色条件对羊毛染色性能的影响,结果表明:在染料用量为6%(owf),染色温度为70℃,染色时间为60 min,酸性大红G和弱酸性红B的染液pH值分别为2和4～5时,改性羊毛可获得较高K/S值。通过实验发现,羊毛通过表面改性处理后,色牢度、水洗牢度和摩擦牢度基本保持不变或略有提高。     

改性甘蔗渣对直接染料吸附性能研究

以柠檬酸改性后的甘蔗渣作为生物吸附剂,对染料直接大红4BS和直接蓝2B进行吸附研究,分析了温度、时间、盐浓度、吸附剂用量、染液初始浓度等因素对染料吸附性能的影响,通过吸附动力学模型和吸附等温线研究了改性甘蔗渣对两种染料的吸附规律和吸附模型。结果表明,在染料浓度50 mg/L,吸附剂加入量1.2 g,pH值为2,吸附温度90℃,吸附时间直接大红4BS为180 min、直接蓝2B为240 min的条件下,改性甘蔗渣对直接大红4BS和直接蓝2B有很好的吸附效果;染液初始浓度对吸附有显著影响,吸附率随着染液初始质量浓度增加而下降;吸附符合二级动力学模型,Langmuir吸附模型能更好地说明吸附行为。     

壳聚糖在棉织物甘蓝红染色中的应用

棉织物经壳聚糖处理后,再用甘蓝红进行染色。探讨壳聚糖改性液浓度、浸渍温度和浸渍时间对改性效果的影响,以及染料用量、pH值、时间和温度对染色效果的影响。结果表明,壳聚糖对棉织物的改性工艺为:壳聚糖改性液25%,80℃浸渍30 min;甘蓝红染色工艺为:染料7%(omf),pH值6,50℃染色60 min。改性后棉织物的染色深度和防紫外线性能均有提高,耐摩擦牢度也较高。     

改性腈纶酸性染料的染色性能

采用盐酸羟胺对腈纶纤维改性,研究了盐酸羟胺用量、醋酸铵用量、改性温度和时间对改性织物染色性能和白度的影响;探讨了该改性织物酸性红B的染色工艺。腈纶纤维优化的改性工艺为:盐酸羟胺12 g/L,醋酸铵20 g/L,80～85℃改性60～90 min;当酸性红B为2%(omf),pH值4～5,90℃以上染色30 min,改性腈纶得色较高;95℃时,酸性红B在改性腈纶上的吸附速率较快,应延长保温时间。     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.