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21.
Danting Yang Nicoleta E. Mircescu Haibo Zhou Nicolae Leopold Vasile Chi Mircea Oltean Yibin Ying Christoph Haisch 《Journal of Raman spectroscopy : JRS》2013,44(11):1491-1496
Ethyl carbamate (EC), a potentially toxic compound, is found in alcoholic beverages and fermented foodstuff. A combined experimental and theoretical study of Raman on EC is reported in this work for the first time. The Raman bands observed for EC in solid phase are characteristic for the carbonyl group, C―C, C―H and N―H stretching and deformation vibrations. These spectral features coupled with a pKa study allowed establishing the neutral species of EC present in the aqueous solutions experimentally tested at different concentrations. In addition, by performing a density functional theory study in the gas phase, the calculated geometry, the harmonic vibrational modes, and the Raman scattering activities of EC were found to be in good agreement with our experimental data and helped establish the surface‐enhanced Raman scattering (SERS) behavior and EC adsorption geometry on the silver surfaces. The Raman peak at 1006 cm−1, assigned to the υs(CC) + ω(CH) modes, the strongest and best reproducible peak in the SERS spectra, was used for a quantitative evaluation of EC. The limit of detection, which corresponds to a signal‐to‐noise ratio equal to 3, was found to be 2 × 10−7 M (17.8 µg l−1). SERS spectra obtained by using hydroxylamine hydrochloride‐reduced silver nanoparticles provide a fast and reproducible qualitative and quantitative determination of EC in aqueous solution. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
22.
An analytical protocol consisting of X‐ray fluorescence spectroscopy, optical microscopy and Fourier transform infrared spectroscopy was used to study the origin and the nature of the materials (pigments, binders and coating preparation) of the Fundenii Doamnei church mural paint from Bucharest. The main interest of the present study consisted in the original votive paint from narthex, painted in 1757 in a secco technique. During analysis, an unexpected pigment in the votive paint could be detected by the combined analytical techniques: ultramarine blue. Along with this pigment, the presence of gypsum binder based on egg and flax seed oil could also be evidenced. These results demonstrated a secco execution technique of the votive paint and also the presence of a restoration treatment. Moreover, during the present study, the components of the preparation layer and the constitutive pigments from both 1699 and 1757 years mural paints have been analyzed. Hence, the following pigments could be identified: vermilion, azurite, cinnabar, lead white, ochre, natural umber and gold, by using the combination of the analytical techniques. The novelty of our results consists in detecting the composition of the materials used in this church painting (fresco and a secco) during these 254 years since its first restoration. The results of these investigations pointed to the suitability of the non‐destructive and semi‐destructive analytical techniques in the complex characterization of the paints realized in different techniques, at different periods. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
23.
Andreea Antonia Georgescu Andreea Eliescu Cristina Mihaela Nicolescu Marius Bumbac Nicoleta Cioateră 《Analytical letters》2019,52(13):2007-2027
The capacities of Pleurotus ostreatus mushroom and spent substrate were evaluated for the biosorption of cadmium (II) from aqueous solution in order to select the most efficient material for bioremediation. The optimum sorption conditions were optimized, including the pH of the aqueous solution, contact time, biomass dosage, initial metal concentration, and temperature. The sorption of cadmium on both biosorbents was also evaluated by several kinetic, equilibrium, and thermodynamic models. The possible heavy metal biosorption mechanisms were evaluated through point of zero charge (pHpzc), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). Based on the results of column studies, the effectiveness of the P. ostreatus spent substrate was confirmed as a biosorbent for Cd(II) removal from aqueous solutions. 相似文献
24.
Leulescu Marian Pălărie Ion Moanţă Anca Cioateră Nicoleta Popescu Mariana Morîntale Emilian Văruţ Marius Ciprian Rotaru Petre 《Journal of Thermal Analysis and Calorimetry》2019,136(3):1249-1268
Journal of Thermal Analysis and Calorimetry - Thermal behavior of Brown HT food dye was studied in correlation with the physical and biological antioxidant properties. Brown HT’s structure... 相似文献
25.
V. V. Grecu S. Constantinescu Maria Nicoleta Grecu Rodica Olar Mihaela Badea Rodica Turcu 《Hyperfine Interactions》2008,183(1-3):205-214
Nanosized magnetite particles embedded in polypyrrole matrix have been studied by Mössbauer and electron magnetic resonance spectroscopy. Comparison with as grown magnetite is made. Hyperfine fields distribution is determined and line shape of resonance curves are discussed in terms of composite structure, sizes and treatments. 相似文献
26.
Samide Adriana Tutunaru Bogdan Merişanu Claudia Cioateră Nicoleta 《Journal of Thermal Analysis and Calorimetry》2020,142(5):1825-1834
Journal of Thermal Analysis and Calorimetry - To prepare a commercial product with economic and technical relevance, polyvinyl acetate (PVAc) was synthesized, under our laboratory conditions,... 相似文献
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Crisan Manuela Vlase Gabriela Plesu Nicoleta Petric Mihaela Croitor Lilia Kravtsov Victor Chumakov Yurii Bourosh Paulina Vlase Titus 《Journal of Thermal Analysis and Calorimetry》2018,132(1):343-351
Journal of Thermal Analysis and Calorimetry - In the present studies, the thermal behaviour of NaUO2BO3 has been investigated. This compound is a potential product of interaction between the... 相似文献
29.
Leulescu Marian Rotaru Andrei Pălărie Ion Moanţă Anca Cioateră Nicoleta Popescu Mariana Morîntale Emilian Bubulică Maria Viorica Florian Gabriel Hărăbor Ana Rotaru Petre 《Journal of Thermal Analysis and Calorimetry》2018,134(1):209-231
Journal of Thermal Analysis and Calorimetry - The food-colouring dye tartrazine is a significant additive and in the same time a biologically active material. Thermal behaviour of trisodium... 相似文献
30.
Nicoleta Petrea Răzvan Petre Andrada Pretorian Constantin Toader Vasile Şomoghi Florentina Neaţu Mihaela Florea Ştefan Neaţu 《Comptes Rendus Chimie》2018,21(3-4):339-345
The catalytic methanolysis of the chemical warfare nerve agents soman, sarin, and VX was investigated by using Cu or Zn complexes. Although VX withstood decontamination, the decomposition yield being around 96%, the soman and sarin deposited on different surfaces were almost fully destroyed under ambient conditions. The catalytic tests performed on a wide range of contaminated surfaces confirm the activity of the investigated catalytic systems, these complexes being suitable, from an economical point of view, for use in the formulation of a possible decomposition kit with military or civilian applicability. 相似文献