Analele Universitatii Ovidius Constanta - Seria Chimie
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Published By De Gruyter Open Sp. Z O.O.

1223-7221, 1223-7221

2014 ◽  
Vol 25 (2) ◽  
pp. 65-70 ◽  
Author(s):  
Ana Leahu ◽  
Sonia Amariei ◽  
Cristina Damian ◽  
Mircea Oroian ◽  
Sorina Ropciuc

Abstract Samples of commercially available Romanian wines were analyzed in order to determine total phenols content and the antioxidant activity. The content of total phenolics in the extracts was determined according to the Folin-Ciocalteu method and calculated as gallic acid equivalents (mg GAE/100g). Antiradical activities of the extracts were evaluated by a micro assay using 1, 1¢-diphenyl-2-picrylhydrazyl spectrophotometric method. Wine characteristics measurements were examined by multivariate data analysis, using principal component analysis (PCA). Total polyphenol content was correlated to the antioxidant activity of the studied wine samples. The values of the inhibition power of free radical, PI%, are ranging between 1.68 for white wine and 0.95 for red wine (“Bull blood” bottled by Tohani winery, Prahova, Romania).


2014 ◽  
Vol 25 (2) ◽  
pp. 81-84
Author(s):  
Doinita Roxana Cioroiu ◽  
Claudia Irina Koncsag

Abstract According to previous studies on the pyrolysis of vegetable oils, it resulted that the thermal cracking process is prone to produce large yields of ethylene, propylene, hydrogen and methane, comparable with the gas proceeding from the steam cracking of naphtha, but at much lower process temperature, this ensuring important energy savings. The studies are performed on very different raw materials and different reaction conditions, that being why at this moment it is very difficult to predict the products yield. This paper uses an analytical semiempirical model (ASEM) developed at the University of Florida, by applying it to a different raw material. The ASEM model fits very well to our experimental data, obtained at higher temperature but some parameters have to be adjusted. In the end we confirm a set of systemic parameters to be used for the prediction of main products yield proceeding from vegetable oil in an extended range of temperatures.


2014 ◽  
Vol 25 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Elisabeta Chirila ◽  
Elena Oancea ◽  
Ioana Adina Oancea

Abstract The purpose of the paper is to present original results concerning characterization of different sea buckthorn (Hippophae rhamnoides L.) extracts and some original dermato-cosmetic products containing these extracts. Aqueous distillate from fruits and leafy branches, aqueous extract from seeds, fresh fruit juice and frozen fruit juice after 2 years of storage, ethanolic extracts of buds have been analyzed for the following parameters: total and organic acidity, oxidability, calcium and magnezium, pH, conductivity, oxidation-reduction potential (ORP). The investigated sea buckthorn extracts have important contribution in care and treatment of skin diseases; during many years of experience in this field great benefits have been observed. Taking into account also the results of previous studies of other researchers we consider that the ORP measurement of cosmetic mixtures could provide objective, cheap and reliable information about antioxidant activity of complex samples.


2014 ◽  
Vol 25 (2) ◽  
pp. 59-64
Author(s):  
Sonia Amariei ◽  
Gheorghe Gutt ◽  
Mircea Oroian ◽  
Alexandra Bodnar

Abstract The goal of this study was to analyze the content of heavy metals in fish, shellfish, molluscs cephalopods on the Romanian market. We have analyzed heavy metals traces in sixteen marine organisms species. Analyses of heavy metal traces were done with mass spectrometer with inductively coupled plasma- ICP-MS, Agilent Technologies 7500 Series. Among the elements identified it was analyzed the content of Cd, Hg, Pb, metals with high toxicity to the human body, and the obtained values were interpreted in accordance with Commission Regulation (EC) No 1881/2006 concerning the maximum allowable quantity per kg wet product and Provisional Tolerated Weekly Intake (PTWI) established by the Joint Committee experts WHO / FAO. The risk assessment performed indicated that marine organisms were safe for the consumer except the four species that cadmium content may be exceeded for a regular or excessive consumption.


2014 ◽  
Vol 25 (2) ◽  
pp. 85-90
Author(s):  
Viorica Popescu ◽  
Alina Soceanu ◽  
Simona Dobrinas

Abstract This paper refers to the quality analysis of three dermo-cosmetic products: two face creams and a biphasic solution used for skin cleaning: a treatment cream for acne complexion, an anti-irritating soothing cream and a matifying purifying lotion. The following characteristics have been investigated: aspect, smell, colour, solubility, type of emulsion, stability test at certain temperatures (4°C and 40°C), pH, melting point, water, volatile substances and total fats contents, acidity, ester index, saponification index, iodine index, peroxide index, microbic carriage, metal traces (determined by ICP-MS method). All analysed dermo-cosmetic products have appropriate physico-chemical characteristics. The analyses made for determining the microbial charge have proven that the three dermo-cosmetic products do not contain any aerobic pathogen germens or micromicetes, Staphylococcus aureus and Escherichia Coli. The ICP-MS analysis has proven that the dermocosmetic products do not contain traces of Hg and Pb.


2014 ◽  
Vol 25 (2) ◽  
pp. 71-74
Author(s):  
Anişoara-Arleziana Neagu ◽  
Irina Niţă ◽  
Elisabeta Botez

Abstract The major objective of this study is to report physico-chemical properties of sunflower oil samples collected from different stages of the technological process for sunflower oil refining for food industry. The samples of oil were crude oil, washed oil, bleached oil and deodorized oil. The physico-chemical properties of sunflower oil experimentally determined were density, saponification value (SV), iodine value (IV), and acid value (AV). It was found that the density of sunflower oil remains approximately constant over the different stages of the manufacturing flow of cooking oil, except the crude oil. The acid value significantly decreases from crude oil (2.588) to deodorized oil (0.366). The iodine value and saponification value of the different samples of the sunflower oil corresponding to different stages of oil processing varies slightly. The capacity of different models to accurately correlate and/or predict the density of vegetable oil was tested. The density of sunflower oil can be accurately estimated from its SV and IV or with an empirical equation, when density data are available.


2014 ◽  
Vol 25 (1) ◽  
pp. 39-42
Author(s):  
Albana Jano ◽  
Alketa Lame ◽  
Efrosini Kokalari

Abstract The corrosion of metal surfaces causes huge financial damages to the industries annually, what has lead to an increase in the search for substances that can slow down or prevent corrosion rate. Green inhibitors which are biodegradable, without any heavy metals and other toxic compounds, are promoted. Amino acids are attractive as corrosion inhibitors because they are nontoxic. We have used methionine as corrosion inhibitor. Materials under investigation are two kind of low allow carbon steel marked as: Steel 39, Steel 44 usually applied to concrete as reinforcing bars, and manufacture in Elbasan. The inhibition effect of methionine on the corrosion behavior of low allow steel is investigated in sulfuric acid in presence of chloride ions, in form of NaCl (H2SO4 1M + Cl- 10-3M). Potentiodynamic polarization method is used for inhibitor efficiency testing. The pitting corrosion current shows that increasing concentration of the inhibitor causes a decrease in pitting current density, and inhibition efficiency increases with increasing concentration of the inhibitors.


2014 ◽  
Vol 25 (1) ◽  
pp. 43-46
Author(s):  
Cristina Ileana Covaliu ◽  
Gina Alina Traistaru ◽  
Gigel Paraschiv

Abstract Methane oxidation using different catalysts is an useful process for preventing air pollution. This study presents the methane oxidation by two types of catalysts: Pd-Sn/Al2O3 and spinel mixed oxide, CuFe2O4. The Pd-Sn/Al2O3 was successfully prepared by sol-gel method and CuFe2O4 by co-precipitation method. The catalysts obtained have been characterized structurally, morphologically and texturally by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). The catalytic activity tests regarding methane oxidation were also performed.


2014 ◽  
Vol 25 (1) ◽  
pp. 11-14
Author(s):  
Albana Jano ◽  
Alketa Lame ◽  
Efrosini Kokalari

Abstract The use of inhibitors is one of the most practical means for protecting metals against corrosion, especially in acidic media. The interest is to use organic compounds as inhibitors due mainly to their inherent and non-toxic nature. Amino acids are attractive as corrosion inhibitors because they are nontoxic, relatively easy to produce with high purity at low cost, and are soluble in aqueous media. Lysine, one kind of amino acid is used as inhibitor. The aims of this study are to show corrosion protection efficiency of lysine and to explain the mechanism of corrosion. The experimental results demonstrated that the lysine offered protection for low alloy carbon steel in aggressive environments like H2SO4. Materials under investigation are two types of low alloy carbon steel marked as: Steel 39, Steel 44 (usually applied to concrete as reinforcing bars). The corrosion media consists in sulfuric acid in presence of chloride ions, in form of NaCl (H2SO4 1M + Cl- 10-3M). Potentiodynamic polarization methods are used for inhibitor efficiency testing. Potentiodymanic polarization measurements showed that the presence of lysine in acidic solution decreases the corrosion current to a good extent. The corrosion inhibition efficiency improves with the increase of the lysine concentration. The use of this inhibitor (1g/L) protects steel 39 in acidic media with 78.88% efficiency. That means lysine is a good corrosion inhibitor for these aggressive conditions.


2014 ◽  
Vol 25 (1) ◽  
pp. 53-58
Author(s):  
Katya Peycheva ◽  
Lubomir Makedonski ◽  
Albena Merdzhanova ◽  
Mona Stancheva

Abstract River ecosystems are vulnerable to heavy metal pollution. Fish samples are considered as one of the most indicative factors, in fresh water systems, for the estimation of trace metals pollution potential since they are the final chain of aquatic web. The objective of the present study is to evaluate the concentration of some toxic elements (As, Hg, Pb, Cd and Ni) in edible part of three wild fresh water fish species (zander (Sander lucioperca), wels catfish (Silurus glanis) and European carp (Cyprinus Carpio)) caught from Bulgarian part of Danube river collected during 2010. The Danube River is the European Union's longest and the continent's second longest river that passes through or touches the borders of ten countries. It has a great importance in regard to biodiversity, economics and transportation. The elements (As, Pb, Cd and Ni) were assayed using Perkin Elmer Zeeman 3030 electrothermal atomic absorption spectrometer with an HGA-600 atomizer. Determination of Hg was performed using Milestone Direct Mercury Analyzer DMA-80. The results were expressed as μg/g dry weight. The order of heavy metal accumulation in the edible part of zander is As>Hg>Pb> Ni> Cd while the other two fish species show a different metal accumulation Hg > As >Pb> Ni > Cd. In all heavy metals, the accumulation of mercuric and arsenic proportion was significantly high in all three fish types.


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