NEW N^N LIGAND WITH HYDROPHYILIC SUBSTITUENTS FOR COORDINATION COMPLEXES BASED ON M(II) BIOMETAL IONS |
Author : Adelina A. ANDELESCU, Carmen CRETU, Liliana CSEH, Sorin MARINESCU, Elisabeta I. SZERB*, Otilia COSTISOR |
Abstract | Full Text |
Abstract :A new N^N chelating ligand based on 2,2’-bisquinoline functionalised with hydrophilic chains and its
coordination complexes with Cu(II) and Zn(II) were synthesized and structurally characterized by IR and 1H NMR
spectroscopies, atomic absorption spectroscopy and elemental analysis. An accurate photophysical characterisation and
conductivity measurements showed the presence of different species in polar solvents solution and in mixtures of
solvent/water. The ligand and its Cu(II) and Zn(II) complexes showed no antioxidant activity. |
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FLUORESCENCE AND THERMAL STUDY OF 3D METAL COMPLEXES CONTAINING HEXADENTATE SCHIFF BASE LIGAND |
Author : Carmen CRETU, Viorel SASCA, Elisabeta I. SZERB, Liliana CSEH*, Otilia COSTISOR |
Abstract | Full Text |
Abstract :New binuclear Zn2(ZOPP-2H)(CH3COO)2 complex (where ZOPP = N,N’-bis[(4-decyloxysalicylideneamino)-
propyl)-piperazine]) has been synthesized and characterized by elemental analysis, 1H- NMR, FTIR,
UV-Vis and fluorescence spectroscopy. The non-electrolyte character of the complex was evidenced by conductivity
measurement. The zinc ions are penta-coordinated by the N2O donor sets namely one phenolate oxygen atom, one imine
nitrogen and one piperazine nitrogen atoms of Schiff base and two oxygen atoms of the acetate group. The Zn(II)
complex displayed fluorescence from the intra-ligand emission excited state in N, N-dimethylformamide (DMF) solution
at room temperature. The thermal behaviour of Zn(II) complex and other Ni(ZOPP-2H) complex previously reported
suggested high stability of these compounds compared to ZOPP ligand. |
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NEW METHOD FOR TESTING MILK ACIDITY BASED ON VOLATILE ORGANIC COMPOUNDS EMISSION |
Author : Oana OLARIU, Dana COPOLOVICI, Lucian COPOLOVICI* |
Abstract | Full Text |
Abstract :Milk storage is one of the most important conditions for people accesses to healthy food. The volatile organic compounds pattern could be a great tool for determination of the fermentation stage. The present paper has been shown that 2-butanone concentration decreased over time of storage while the acetic acid concentration depends not only by time but also by storage temperature. The emission of acetic acid could be used as a marker of fermentation degree and its concentration has been correlated with the classical approach of Thorner degrees measurements. |
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POTASSIUM FERROCYANIDE WINE TREATMENT: A CONTROVERSIAL, YET NECESSARY OPERATION |
Author : Ionel POPESCU-MITROI,* Dana RADU |
Abstract | Full Text |
Abstract :This paper presents the method of iron removal from wine by using a potassium ferrocyanide treatment, a method implemented in Romania by oenologist Stefan Teodorescu, which became official in 1973. Potassium ferrocyanide treatment is a controversial operation that poses safety and environmental protection problems but is absolutely necessary for the efficient removal of iron from wines rich in this cation. Without iron removal, wines with over 10 mg/l of iron become susceptible to fearsome chemical defects, such as turning whiter, darker or blusher. The paper presents a case study for the white wine Feteasca Regala, obtained in the Recas vineyard, harvested in 2016, in order to establish the theoretical and practical doses of potassium ferrocyanide based on microprobes, to remove the iron up to the safety threshold (4 mg Fe total/l of wine). The conclusions of the paper include some “good practices” for the success of the treatment and the prevention of toxicity problems. |
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QUANTITATIVE STRUCTURE-FRAGMENTATION RELATIONSHIP TECHNIQUE APPLIED FOR DISCRIMINATION OF cis-B-OCIMENE AND trans-B-OCIMENE FROM LAVENDER OIL |
Author : Lucian COPOLOVICI, Dumitru CONDRAT, Nicolae DINCA* |
Abstract | Full Text |
Abstract :Elucidation by mass spectrometry of isomeric structures only by using a library search presents difficulties due to the high similarity of the spectra. So, the GC-MS analysis of trans-?-ocimene and cis-?-ocimene, biologically active compounds from lavender oil, offers contradictory results when are used mass spectral libraries and retention indeces database. Under these circumstances, supplementation of analysis with an independent path is absolutely necessary to clarify the configuration of these compounds. Quantitative structure-fragmentation relationships (QSFR) techniques offer such a possibility. These techniques use thermochemical data obtained through quantum chemical calculation (QCC) for structures which should be discriminated against. In our paper we opted for an ordering algorithm (ORD) which gives good results in the case of high similarity spectra. ORD uses the inverse sorting of the relative intensities’ row of the main isobaric ions with the corresponding enthalpies’ row. The result thus obtained validates the structures achieved by retention indices. One of the advantages of this approach is that the use of these three analytical variants can provide high accuracy of analysis without the direct use of chemical standards. |
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DETERMINATION OF ASCORBIC ACID IN FRUIT JUICES |
Author : Simona GAVRILA?, Florentina-Daniela MUNTEANU* |
Abstract | Full Text |
Abstract :The present study has in attention the determination of ascorbic acid in beverages. This presents important interests as the amount of C vitamin content in certain food products, especially in beverages, has to be known by the consumers. Moreover, the food industry should not add more than 20% than the amount of vitamin C that is declared on the label. We propose an electrochemical method for the determination of ascorbic acid using the standard addition method. It was found that in most of the cases, the declared concentration of C vitamin is much lower than the ones found through electrochemical detection. |
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THE EFFECT OF PULSED ELECTRIC FIELD AND WINE AGING ON TOTAL PHENOL CONTENT AND COLOUR OF RED WINES |
Author : Alin TEUSDEA1, Livia BANDICI2, Gheorghe Emil BANDICI1, Simona VICAS1* |
Abstract | Full Text |
Abstract :Pulsed Electric Field (PEF) is a non-thermal emerging technology that is applied as pre-treatment to the extraction of bioactive compounds from grapes in order to obtain high quality wine. In the present work, we applied PEF treatment (with different parameters) to two varieties of red grapes (Pinot Noir and Merlot) and recorded the total phenols and chromatic properties (RGB, CIE L*a*b*, CIE L*C*h*, wine colour index (CI), and wine tint (Tint)) of fresh (November 2016) and aged wines (6 months, April 2017). Our results showed that the efficiency of PEF treatment depends on the variety of grapes. The best extractivity of total phenols was obtained for Pinot Noir grapes, compared to Merlot (2.5 times, and 1.4 times, respectively, compared to the untreated sample). All PEF treatments, for both Pinot Noir and Merlot wines, produce an increase in wine quality by positive higher levels of chromatic properties, wine colour properties. These properties are changing with the aging of wine, but differently for Pinot Noir and Merlot wines. Our results show the PEF treatment can be used in the winemaking process in order to increase the phenol content and consequently colour intensity in the red wine. |
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CASE STUDIES OF FORMER ROMANIAN ERASMUS STUDENTS |
Author : Dana Maria COPOLOVICI*, Denissa Arabela POP |
Abstract | Full Text |
Abstract :Student mobility, particularly Erasmus is a programme developed by European Union in 1987 aiming to increase the educational, cultural, and social interactions between young people from different universities. Many Romanian students were involved in this programme. The present study evaluated the motivation and the impact of the study stage abroad of two Romanian former students including their human development and career evolution. |
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THE INFLUENCE OF FREEZING ON THE CONTENT OF VITAMIN C, CHLOROPHYLLS AND CAROTENOIDS IN CHIVES (ALLIUM SCHOENOPRASUM L.) |
Author : Alice IOSIN, Diana-Nicoleta RABA, Camelia MOLDOVAN, Viorica-Mirela POPA, Delia-Gabriela DUMBRAVA* |
Abstract | Full Text |
Abstract :In this paper we analyzed the influence of freezing at -18°C for 4 months, for blanched and non-blanched chives (Allium schoenoprasum L.) on the content of ascorbic acid, chlorophylls and carotenoids. In the case of fresh chives, the vitamin C content (determined by iodometric method) was 56.48 mg/100g; for frozen non-blanched chives, were determined losses of 49.91% and for frozen blanched chives, losses of 15.88%. The total chlorophylls concentration (determined by spectrophotometry) in fresh chives was 268.15 µg/g, of which 205.00 µg/g chlorophyll “a” and 63.15 µg/g chlorophyll “b”, respectively. After the freezing treatment on the fresh chives there were determined losses of 18.95% from total chlorophylls, 18.27% chlorophyll “a” and 21.14% chlorophyll “b”. Freezing of the blanched chives has caused less loss of chlorophylls (9.58% loss of total chlorophylls) compared with the same treatment applied to fresh chives. The content of carotenoids determined by using spectrophotometric methods, revealed that fresh chives had 36.41 µg/g, and losses were of 31.86% for frozen non-blanched chives and of 16.97% for frozen blanched chives. |
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