Papers by Dorina Rusu Simedru
Structural investigations of some Bi2O3 based glasses
OPTOELECTRONICS AND ADVANCED MATERIALS-RAPID COMMUNICATIONS
A comparative structural study was made on the glass systems xFe 2O3·(100-x)Bi2O3 and xFe 2O3-(10... more A comparative structural study was made on the glass systems xFe 2O3·(100-x)Bi2O3 and xFe 2O3-(100-x)[Bi2O3·MO] (where MO => CdO, AS2O3 and GeO2), with 0 ≤ × ≤50 mol%. The samples were prepared and investigated by X - ray diffraction, FT-IR and Raman spectroscopies in order to determine their local structure. From FT - IR spectra it can be observed that, in all studied oxide matrices, the predominant structural units are those characteristic to Bi 2O3 and also some structural units characteristic to AS2O3, GeO4 and Fe2O3 were evidenced. The Raman spectra confirm the structure proposed by FTIR. By both, FT - IR and Raman spectroscopies, it can be observed that the controlled dopping with iron ions induce some structural changes in the glass matrices.
Structural investigation of xMnO·(100−x)[As2O3·PbO] glass system by FT-IR and Raman spectroscopies
Solid State Sciences, 2008
xMnO·(100−x)[As2O3·PbO] glass system, with 0≤x≤5mol%, was studied by FT-IR and Raman spectroscopi... more xMnO·(100−x)[As2O3·PbO] glass system, with 0≤x≤5mol%, was studied by FT-IR and Raman spectroscopies in order to determine their structure and to point out the role of each component of the glass system in the formation of the glass network. FT-IR spectrum of the glass matrix shows the presence of AsO3, PbO4 and PbO3 structural units. The Raman spectrum of the glass matrix confirms the structure proposed by FT-IR. By both FT-IR and Raman spectroscopies, the presence of structural units characteristic to MnO was not directly observed.
Determination of Two Textile Dyes in Wastewater by Solid Phase Extraction and Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry Analysis
Journal of Liquid Chromatography & Related Technologies, 2012
This study describes a procedure for the determination of two textile dyes (Nylosan Red N-2RBL - ... more This study describes a procedure for the determination of two textile dyes (Nylosan Red N-2RBL - azo and Optilan Blue MF-GL - anthraquinone) from wastewater by solid phase extraction and liquid chromatography/electrospray ionization tandem mass spectrometry (SPE-LC/ESI-MS/MS) analysis. Four types of Strata SPE cartridges (C18-U, C18-E, WAX/NH2 and SAX) were tested, the best results being obtained on Strata WAX/NH2. The
INFLUENCE OF THE PREPARATION CONDITIONS AND THERMAL TREATMENT ON THE STRUCTURE OF THE B 2 O 3 -BaO-Fe 2 O 3 SYSTEM
International Journal of Modern Physics B, 2005
The structure of xFe2O3·(100-x)[3B2O3·BaO] system with 0<=x&lt... more The structure of xFe2O3·(100-x)[3B2O3·BaO] system with 0<=x<=50 mol% was studied by DTA, X-ray diffraction, density, optical microscopy and EPR measurements in vitreous and partial crystallized state, the samples being obtained by under cooling method. The data obtained show that, by melting the samples at Te = 1200°C or Te = 1250°C, glasses for x<=35 mol% were obtained, and the forming
Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 2014
The aim of this study was to investigate the concentration level of some major-to-trace elements ... more The aim of this study was to investigate the concentration level of some major-to-trace elements and toxic minerals and polyphenols (catechin, epicatechin and quercetin) in fruits belonging to different apple cultivars ('Auriu de Cluj', 'Florina', 'Generos', 'Golden Delicious', 'Prima', 'Productiv de Cluj' and 'Starkrimson'), under specific climate conditions to northwestern Romania. The apple minerals were determined by the inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) after a preliminary, microwave-assisted, acid digestion. The polyphenols were determined by high performance liquid chromatography (HPLC) with MS/MS detection. According to the obtained results, the edible part of the apple contains many minerals with high relative nutritional value (RNV). The major minerals (Na, K, Ca, Mg and P), minor elements (Cu, Fe, Mn, Sr and Zn) and toxic trace elements (Cd, Cr and Pb) were comparatively identified and quantified. It was found that K (31976 mg/kg) was predominant among the major elements, while Fe (3.68 mg/kg) and Cu (3.57 mg/kg) were comparable. The toxic trace metals (Cd, Cr and Pb) were below the limits of detection (0.01, 0.10 and 0.01 mg/kg, respectively) and did not determine any health risk to consumers. The main polyphenols composition (catechin, epicathechin, quercetin) differs slightly among different cultivars. In 'Idared' and 'Jonathan' cultivars, the investigated polyphenols are in higher quantities comparing to the others. In all investigated apple cultivars, quercetin was proved to be the major polyphenol, followed by epicathechin and catechin. These results suggest that, regarding only the investigated polyphenols, 'Idared' and 'Jonathan' cultivars have the highest antioxidant character in all investigated genotypes.
EPR and FT-IR spectroscopic studies of Bi2O3–B2O3–CuO glasses
Physica B: Condensed Matter, 2008
EPR and FT-IR absorption measurements have been performed for xCuO·(100− x)[2Bi2O3· B2O3] glass s... more EPR and FT-IR absorption measurements have been performed for xCuO·(100− x)[2Bi2O3· B2O3] glass system, with 0⩽ x⩽ 50mol%. The mode in which the addition of the copper ions influences the structure of 2Bi2O3· B2O3 glass matrix was analyzed. The EPR absorption ...
Structural studies of Fe2O3–Bi2O3–CdO glass system
Materials Research Bulletin, 2008
xFe2O3·(100−x)[Bi2O3·CdO] system with 0≤x≤50mol% was prepared and investigated by X-ray diffracti... more xFe2O3·(100−x)[Bi2O3·CdO] system with 0≤x≤50mol% was prepared and investigated by X-ray diffraction, density, FT-IR and Raman spectroscopies. The XRD patterns confirm the formation of a vitreous structure for x<35mol% Fe2O3. The evolution of density and molar volume with the addition and increasing of iron content indicates structural changes in the structure of Bi2O3·CdO glass matrix. The FT-IR spectrum of the glass matrix reveals a structure realized from BiO3 pyramidal and BiO6 octahedral units. With the addition of iron the structure proposed by the glass matrix is changing by the appearance of FeO4 units. Also the existence of FeO6 units cannot be excluded. The Raman spectra suggest a structure build from BiO6 octahedral units. By Raman scattering the presence of structural units characteristic to Fe2O3 was not directly observed but the evolution of the spectra is dependent of the iron content.
Raman study of xMeO·(100−x)[P2O5·Li2O] (MeO⇒Fe2O3 or V2O5) glass systems
Materials Letters, 2007
Glasses from xMeO·(100−x)[P2O5·Li2O] (MeO⇒Fe2O3 or V2O5) systems, with 0≤x≤50 mol%, were prepared... more Glasses from xMeO·(100−x)[P2O5·Li2O] (MeO⇒Fe2O3 or V2O5) systems, with 0≤x≤50 mol%, were prepared and investigated by Raman spectroscopy. The influence of Fe2O3 and V2O5 content on the structure of P2O5·Li2O glass matrix was followed.The P2O5·Li2O glass matrix presents three absorption bands characteristic to metaphosphate chain structures. The addition of Fe2O3 or V2O5 determines the modification of the structure of the studied glasses.
Journal of Materials Science: Materials in Electronics, 2007
xV 2 O 5 Á ð100 À xÞ½P 2 O 5 Á Li 2 O glass system, with 0 < x 50 mol%, was prepared and investig... more xV 2 O 5 Á ð100 À xÞ½P 2 O 5 Á Li 2 O glass system, with 0 < x 50 mol%, was prepared and investigated by EPR method. For low content of V 2 O 5 all the spectra present a hyperfine structure typical for isolated V 4+ ions. With the increasing of V 2 O 5 content, the EPR absorption signal showing hyperfine structure is superposed by a broad line without hyperfine structure characteristic for clustered ions. At high V 2 O 5 content, the vanadium hyperfine structure disappears and only the broad line can be observed in the spectra.
Structural investigation of xFe2O3 · (100 − x)[P2O5 · TeO2] glass system by FT-IR study and EPR spectroscopy
Journal of Materials Science: Materials in Electronics, 2009
... J Mater Sci: Mater Electron (2009) 20:905–910 909 123 Page 6. 27. V. Cerny, B. Frumarova, J. ... more ... J Mater Sci: Mater Electron (2009) 20:905–910 909 123 Page 6. 27. V. Cerny, B. Frumarova, J. Rosa, IL Licholit, P. Urban, Phys. Status Solidi B 61, 475 (1974). doi:10.1002/pssb. 2220610212 28. SP Chaudhuri, SK Patra, J. Mater. Sci. 35, 4735 (2000). ...
Structural investigations of V2O5–P2O5–CaO glass system by FT-IR and EPR spectroscopies
Journal of Materials Science, 2012
Abstract xV 2 O 5·(100− x)[0.7 P 2 O 5· 0.3 CaO] glass system was obtained for 0≤ x≤ 35 mol% V 2 ... more Abstract xV 2 O 5·(100− x)[0.7 P 2 O 5· 0.3 CaO] glass system was obtained for 0≤ x≤ 35 mol% V 2 O 5. In order to obtain information regarding their structure, several techniques such as X-Ray diffraction, FT-IR, and EPR spectroscopies were used. X-Ray diffraction ...
METHOD DEVELOPMENT FOR CIPROFLOXACIN ANALYSIS IN HONEY BY LC-MS/MS
Agricultura, agricultural practice and science journal, 2010
Agricultura, agricultural practice and science journal, 2010
Many chemicals which are released into the environment and have the potential to disrupt the func... more Many chemicals which are released into the environment and have the potential to disrupt the function of endocrine systems are called endocrine disrupting chemicals. A category included in these EDCs is the estrogens. A significant representative of this category is 17β-estradiol which is excreted by both male and female. Its presence in waste water is very dangerous because, following the path of waste water; it goes to rivers causing significant damage to fish environment. Due to its importance, a method was developed for screening and confirming 17β-estradiol residue in waste water samples. Method development consisted in preparing the standard solutions, optimizing the compound and source dependent parameters, choosing the mobile phase and the appropriate HPLC column followed by processing a calibration curve and finally injecting a real sample. The waste water sample was extracted according to some bibliographic studies, then injected on a Phenomenex Luna C18 column and detected through a LC/MS/MS system in an ESI (electrospray ionization) negative mode. The results were considered to be satisfying.
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Papers by Dorina Rusu Simedru