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31.
Andreas Miller Eva Lassek Julia Pfister Richard Klinger Werner Höbel Holger Knapp Franziska Gaßmann Uwe Wollein Nicholas Schramek 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2016,11(2):127-135
In the European Union, carminic acid and its ammonium, calcium, potassium or sodium salts and its aluminium lakes are approved as food additive E120. In beverages obtained from the German market 4-aminocarminic acid (“acid-stable carmine”) was detected by HPLC–PDA and LC–MS/MS. Isolation of the colorant from a liquid dye preparation used for the production of a beverage sample and subsequent NMR analysis confirmed the presence of 4-aminocarminic acid. Synthesis of 15N-4-aminocarminic acid clearly demonstrated that “acid-stable carmine” is not the ammonium salt of carminic acid, which is approved as food additive in the European Union. In fact, nitrogen in “acid-stable carmine” is covalently bound. The molecular structure of carminic acid is chemically modified and 4-aminocarminic acid does not comply with the specifications laid down for E120 in Commission Regulation (EU) No 231/2012. 4-Aminocarminic acid was also detected in the red-colored glaze of a raspberry cake and in the liquid dye preparation used for coloring this glaze. 相似文献
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On the basis of standards of identification of substances in the additive system of polyethylene has been performed. Different methods for separation such as adsorption thin-layer chromatography, high-performance liquid chromatography with chemically bounded phases, and gas chromatography have been used. The fir al identification has been made with mass spectrometry. The substances have been extracted from polyethylene with hexane and chloroform. 相似文献
34.
Preparation of Nanosized Hematite Particles by Mechanical Activation of Goethite Samples 总被引:4,自引:0,他引:4
Jan ubrt Luis A. Pérez-Maqueda Jose M. Criado Concepción Real Jaroslov Boháek Eva Veerníková 《Journal of the American Ceramic Society》2000,83(2):294-298
Nanosized single crystals of hematite with a very narrow particle size distribution were prepared by mechanical activation of two different goethite samples. Both goethite samples transformed completely into hematite after 70 h grinding time. Transmission electron microscopy showed that the final particles were spherical in shape and of ∼17 nm average particle size. This particle size was coincident with that estimated from specific surface measurements, indicating that the hematite samples consisted of nonporous and nonaggregated particles. The crystallite size, calculated from the broadening of the XRD peaks, in the hematite samples indicated that particles consisted of single crystals. No influence of the precursor was observed in the products, so both goethite samples yielded identical rounded single crystals with a narrow particle size distribution. 相似文献
35.
Asmaa Elbakry Eva‐Christina Wurster Alaa Zaky Renate Liebl Edith Schindler Petra Bauer‐Kreisel Torsten Blunk Reinhard Rachel Achim Goepferich Miriam Breunig 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(24):3847-3856
Because nanoparticles are finding uses in myriad biomedical applications, including the delivery of nucleic acids, a detailed knowledge of their interaction with the biological system is of utmost importance. Here the size‐dependent uptake of gold nanoparticles (AuNPs) (20, 30, 50 and 80 nm), coated with a layer‐by‐layer approach with nucleic acid and poly(ethylene imine) (PEI), into a variety of mammalian cell lines is studied. In contrast to other studies, the optimal particle diameter for cellular uptake is determined but also the number of therapeutic cargo molecules per cell. It is found that 20 nm AuNPs, with diameters of about 32 nm after the coating process and about 88 nm including the protein corona after incubation in cell culture medium, yield the highest number of nanoparticles and therapeutic DNA molecules per cell. Interestingly, PEI, which is known for its toxicity, can be applied at significantly higher concentrations than its IC50 value, most likely because it is tightly bound to the AuNP surface and/or covered by a protein corona. These results are important for the future design of nanomaterials for the delivery of nucleic acids in two ways. They demonstrate that changes in the nanoparticle size can lead to significant differences in the number of therapeutic molecules delivered per cell, and they reveal that the toxicity of polyelectrolytes can be modulated by an appropriate binding to the nanoparticle surface. 相似文献
36.
Jan Paca Eva Klapkova Martin Halecky Kim Jones Carlos Riccardo Soccol 《Clean Technologies and Environmental Policy》2007,9(1):69-74
The removal of a mixture of painting solvents from waste air using a biofiltration process was evaluated in this project. The pollutants removed included hydrophobic (aromatic hydrocarbons) and hydrophilic (water soluble ketones and esters) compounds. A trickle bed reactor with a defined immobilized mixed culture on polyethylene Pall rings was utilized in this biodegradation study. The removal efficiencies (RE) of the individual groups of pollutants during loading experiments were determined. An increase of the aromatic hydrocarbons loading resulted in a drop of their REAROM with no effect on the RE value of ketones. The overloading of ketones caused a rapid drop in REAROM and a small drop in REKET. To achieve a restoration of the biocatalyst degradation properties after the increase in loading, an addition of phosphate to the aqueous medium was implemented which successfully restored the removal efficiency. 相似文献
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Ballesteros B Tobias G Shao L Pellicer E Nogués J Mendoza E Green ML 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(9):1501-1506
Purification and shortening of single-walled carbon nanotubes (SWNTs) is carried out by treatment with steam. During the steam purification the graphitic shells coating the catalytic metal particles are removed. Consequently, the exposed catalytic particles can be easily dissolved by treatment with hydrochloric acid. No damage to the carbon nanotube tubular structure is observed, even after prolonged treatment with steam. Samples are characterized by HRTEM, TGA, magnetic measurements, Raman spectroscopy, AFM, and XPS. 相似文献
39.
Eva Hopma Ashwin Ittoo Yuan Lu Ilse Luyk Laura Maruster Joël Ribeiro Ton Weijters Hans Wortmann 《Quality and Reliability Engineering International》2012,28(8):873-886
Advance technology development and wide use of the World Wide Web have made it possible for new product development organizations to access multi‐sources of data‐related customer complaints. However, the number of customer plaints of highly innovative consumer electronic products is still increasing; that is, product quality and reliability is at risk. This article aims to understand why existing solutions from literature as well as from industry to deal with these increasingly complex multiple data sources are not able to manage product quality and reliability. Three case studies in industry are discussed. On the basis of the case study results, this article also identifies a new research agenda that is needed to improve product quality and reliability under this circumstance. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
40.
Yoon DK Yi Y Shen Y Korblova ED Walba DM Smalyukh II Clark NA 《Advanced materials (Deerfield Beach, Fla.)》2011,23(17):1962-1967