Nicoleta Chira - Academia.edu (original) (raw)
Papers by Nicoleta Chira
Biochemical composition and physical appearance of linseed oil determine the quality of the oils ... more Biochemical composition and physical appearance of linseed oil determine the quality of the oils extracted for various industrial uses. The behavior of 11 genotypes of linseed from south of the country was analyzed, on the basis of multiannual testing in competitive crops, in order to study the influence of climatic conditions on agronomic characteristics and physicochemical properties of linseed. Genotype-environment interaction has proven to be very significant for production potential. As yield potential, the brown seed genotypes were highlighted, these recording the highest yields between 2390 and 2430 kg/ha oil content. As oil content, the both yellow and brown seed genotypes were emphasized. The oil content of analyzed genotypes ranged between 43.05 and 47.22%. The unsaturated fatty acids: oleic (14.4 to 22.07%), linoleic (14.88 to 18.48%) and linolenic (49.97 to 60.68%) which determine the quality and sicativity of linseed oil were tested. As part of breeding material, there ...
spectroscopy (IR), based on trans specific bonds absorption at 966 cm -1 (while the absorption of... more spectroscopy (IR), based on trans specific bonds absorption at 966 cm -1 (while the absorption of the cis bonds appears at 724 cm -1 ). Based on the measurement of the absorption band at 966 cm -1 , a calibration curve was obtained. The results were compared with those obtained by gas chromatography-mass spectrometry technique (GC-MS) used as reference method to quantify the trans fats. The results obtained demonstrated that trans fatty acids formation in vegetable oils during heating, is closely related to process temperature and time and also that trans fatty acids can only be formed under severe conditions.
Seven species of fish (salmon, mackerel, catfish, two species of phytophagous fish, cod liver, br... more Seven species of fish (salmon, mackerel, catfish, two species of phytophagous fish, cod liver, bream) were studied for their oil fatty acids composition. Crude fish oils were obtained by standard Soxlet extraction method. Identification and quantitative measurement of fish oils fatty acids were carried out by gas chromatography coupled with mass spectrometry and by H-NMR spectroscopy. Fourteen individual fatty acids were identified using GC-MS technique. GC-MS was applied on fatty acids methyl esters. Identification of fatty acids from oil samples was made using a standard mixture of 37 fatty acid methyl esters. H-NMR spectroscopy gives information about classes of unsaturated and saturated fatty acids. By this method can also determine the ω-3 and docosahexaenoic fatty acid content. Using both analytical methods, polyunsaturated fatty acids important for human health (eicosapentaenoic and docosahexaenoic acids) were identified and quantified.
MARIA-CRISTINA TODASCA1*, LAURA FOTESCU2, NICOLETA-AURELIA CHIRA1, CALIN DELEANU3, SORIN ROSCA1 1... more MARIA-CRISTINA TODASCA1*, LAURA FOTESCU2, NICOLETA-AURELIA CHIRA1, CALIN DELEANU3, SORIN ROSCA1 1University Politehnica Bucharest, Faculty of Applied Chemistry and Material Science, „C. Nenitescu” Organic Chemistry Department, 1-7 Polizu St., 011061, Bucharest, Romania 2 Researches and Development Institute for Viticulture and Vineyard, Valea Calugareasca, Romania 3 Romanian Academy, Center of Organic Chemistry “C. D. Nenitzescu”, 202B Spl. Independentei, 060023, Bucharest, Romania
Această lucrare prezintă utilizarea spectroscopiei de rezonanţă magnetică nucleară de proton si c... more Această lucrare prezintă utilizarea spectroscopiei de rezonanţă magnetică nucleară de proton si cromatografia de gaze pentru determinarea indicilor de calitate ai uleiurilor vegetale. Pe baza datelor 1 H-RMN, s-au dedus ecuaţii chemometrice care permit calcularea masei moleculare medii si indicilor de iod si de saponificare ai uleiurilor vegetale. Aceste rezultate au fost comparate cu valorile obţinute prin metodele standard de analiză si s-au dovedit a fi in concordanţă cu acestea. This work presents the use of proton nuclear magnetic resonance spectroscopy and gas-chromatography for the determination of quality indices of vegetable oils. Based on the 1 H-NMR data, chemometric equations were developed, leading to the computation of the average molecular weight, iodine and saponification indices of vegetable oils. The results were compared with those obtained by standard methods and proved to be in agreement.
Nuclear magnetic resonance (NMR) spectroscopy coupled with Principal Components Analysis (PCA) ch... more Nuclear magnetic resonance (NMR) spectroscopy coupled with Principal Components Analysis (PCA) chemometrical method were used to characterize juices and wines obtained from four types of forest fruits (strawberries, blackberries, raspberries and blueberries) and three varieties of grapes (Muscat Ottonel, Fetească Albă and Burgund). H-NMR spectroscopy provided two sets of data that can be used to classify juices and wines. The first set of data used in PCA was the absolute concentrations of compounds identified in juices and wines. The second set of data was obtained by transforming the H-NMR spectra into strings of numerical values by integrating relevant spectral windows in steps of 0.2 ppm. Those sets of data were further used to discriminate juices and wines according to the row material.
We report here the synthesis of an azo dye bearing monomer by grafting 4-hydroxy-4’-nitroazobenze... more We report here the synthesis of an azo dye bearing monomer by grafting 4-hydroxy-4’-nitroazobenzene onto the epoxidized linseed oil (ELO) backbone thus leading to coloured epoxidised compounds. The reaction product was further crosslinked with ELO under acidic conditions (BF3·Et2O), obtaining a coloured crosslinked material, which was characterised by FTIR spectroscopy and thermo gravimetric analyses. Prior to the azo dye functionalization, the starting material (ELO) has been characterized by spectroscopic (1H-NMR and FTIR) methods in order to chemometrically determine the chemical composition and the epoxide amount per gram of ELO. The chemometric approach is exhaustively presented.
2 "Gheorghe Ionescu-Siseoti" Academy of Agricultural and Forestry Sciences, 61 Maraoti ... more 2 "Gheorghe Ionescu-Siseoti" Academy of Agricultural and Forestry Sciences, 61 Maraoti Blv, 011464, Bucharest, Romania This paper presents the use of gas-chromatographic technique of compositional analysis of oils for the examination of the efficiency of different fertilization treatments applied to sunflower and rapeseed. Two series of oilseeds (sunflower and rapeseed) simultaneously grown in the same geographic aria and of the same variety but treated with different fertilizers have been analyzed. The efficiency of the agrotechnical treatments was determined on the basis of the oilseed production increase (kg/ha), oil production increase (kg/ha) and of some quality indices of oils (ω-3 fatty acid content, ω-3/ ω-6 ratio).
The fatty acid composition of vegetable oils is the main factor influencing their properties, con... more The fatty acid composition of vegetable oils is the main factor influencing their properties, concerning both nutrition [1, 2] and exploitation as raw materials for oleochemistry [3-6]. In recent years, interest of scientist to develop new and efficient methods for the determination of the fatty acid profile of different kind of samples (edible oils [7], lipid extracts from different human [8] or animal tissues [9], etc.), has increased, being partially fed by the general trend in the chemical literature concerning the food authenticity assessment. Among the most envisaged physical methods of analysis, gas-chromatography is by far the most popular [10], but 1H-NMR spectroscopy is considered an interesting alternative [11, 12]. The present paper aims to exploit the potential of the 1H-NMR spectroscopy regarding structural and compositional information applied to vegetable oils field, as well as its non-destructive nature and mild analysis conditions which does not require chemical tr...
Journal of Food Measurement and Characterization
The present study aims at optimising the oil extraction from Dragon’s head ( Lallemantia iberica ... more The present study aims at optimising the oil extraction from Dragon’s head ( Lallemantia iberica ) seeds using response surface methodology. For this purpose, the working conditions (solid/liquid ratio, ultrasound intensity and extraction time) were varied in a series of experiments to determine the optimum extraction conditions, which were further verified through an independent extraction experiment. The experiments were conducted using ultrasound-assisted extraction (UAE) technique. The maximum yield obtained for UAE extraction efficiency under optimal conditions was 97.02%, taking the Soxhlet technique as a reference (corresponding to an oil content of 39.73 g/100 g dry seeds). The operation conditions for maximum extraction efficiency were: 1/16 (g/mL) solid/liquid ratio, 13.77 (W/cm 2 ) ultrasound intensity and 12.5 min extraction time.
Sustainability
Cnicus benedictus fruits were used as raw material to extract oil, and the resulting oil was conv... more Cnicus benedictus fruits were used as raw material to extract oil, and the resulting oil was converted into biodiesel. Two extraction methods were tested: batch extraction, and ultrasound assisted extraction. Response surface methodology was considered for the optimization of the process efficiency. The selected key independent variables were temperature, extraction time, and solid/liquid ratio for batch extraction and ultrasound intensity, temperature, and extraction time for the ultrasound assisted extraction, respectively. The optimal working conditions are different for the two extraction techniques, with respect to temperature, solid/liquid ratio, and extraction time, respectively, leading to higher extraction efficiency in the case of the ultrasound-assisted extraction. Cnicus benedictus oil obtained under the optimal extraction conditions was further esterified with methanol under acid catalysis to yield biodiesel. The biodiesel was characterized through 1H-NMR and the main f...
NICOLETA-AURELIA CHIRA1*, MARIA-CRISTINA TODASCA1, GABRIELA PAUNESCU2, IONICA DAVID3, NICULINA IO... more NICOLETA-AURELIA CHIRA1*, MARIA-CRISTINA TODASCA1, GABRIELA PAUNESCU2, IONICA DAVID3, NICULINA IONESCU3, MARIA STANCIU3, SORIN ROSCA1 1 “Politehnica” University of Bucharest, Organic Chemistry Department, 1-7 Polizu Str., Bucharest, 011061, Romania. 2 Agricultural Research and Development Station aimnic, Dept of Plant Breeding, Craiova, Romania. 3 National Agricultural Research and Development Institute (NARDI), 915200, Fundulea, 1 Nicolae Titulescu Str., Cãlãraoi County, Romania
MIHAELA MIHALACHE1, AURELIA BRATU1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA T... more MIHAELA MIHALACHE1, AURELIA BRATU1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA TODASCA1, SORIN ROSCA1 1 University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, “Costin D. Nenitzescu” Organic Chemistry Department, 1-7 Polizu Str., 011061, Bucharest, Romania 2 Romanian Academy, Organic Chemistry Center “Costin D. Nenitzescu” 202B Splaiul Independentei, 060023, Bucharest, Romania
MARIA-CRISTINA TODASCA1* LAURA FOTESCU2, FULVIA ANCUTA HINCU3, ANAMARIA HANGANU1, NICOLETA-AURELI... more MARIA-CRISTINA TODASCA1* LAURA FOTESCU2, FULVIA ANCUTA HINCU3, ANAMARIA HANGANU1, NICOLETA-AURELIA CHIRA1, SORIN ROSCA1 1 University Politehnica Bucharest, Faculty of Applied Chemistry and Material Science, „C. Nenitescu” Organic Chemistry Department, 1-7 Polizu Str., 011061, Bucharest, Romania 2 Researches and Development Institute for Viticulture and Vineyard, Valea Cãlugãreasca, Romania 3 Institute of Food Bioresources, 6 Dinu Vintila Str., 021102, Bucharest, Romania
AURELIA BRATU1, MIHAELA MIHALACHE1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA T... more AURELIA BRATU1, MIHAELA MIHALACHE1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA TODASCA1, SORIN ROSCA1 1 University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, “Costin D. Nenitzescu” Organic Chemistry Department, 1-7 Polizu Str., 011061, Bucharest, Romania 2 Romanian Academy, Organic Chemistry Center “Costin D. Nenitzescu” 202B Splaiul Independentei, 060023, Bucharest, Romania
The fermentations of some Romanian grape musts with Saccharomyces cerevisiae yeast were studied u... more The fermentations of some Romanian grape musts with Saccharomyces cerevisiae yeast were studied under different conditions: natural fermentations (without additional yeast), induced fermentation using different amounts of selected yeasts and industrial fermentation. The wines fermentations have been daily monitored using 1H nuclear magnetic resonance (1H-NMR) spectroscopy. Based on the 1H-NMR spectroscopy and applying multivariate statistical analysis, we studied the changes in the chemical compositions of wines depending on the alcoholic fermentation conditions establishing the influence of yeast used in the process.
Sensors and Actuators B: Chemical
Sensors and Actuators B: Chemical
Abstract The synthesis of a series of thiosemicarbazone ligands bearing azido groups, which were ... more Abstract The synthesis of a series of thiosemicarbazone ligands bearing azido groups, which were further immobilized on the surface of phenylethynyl-functionalized glassy carbon (GC) electrodes through a Cu(I)-catalyzed "click" reaction is reported. The modified electrodes presented a remarkable selectivity towards Hg(II) among other metal ions. Under optimized conditions and using the accumulation at open circuit-anodic stripping technique, detection limits below nanomolar level were obtained for Hg(II). Further, we demonstrated that GC electrodes "clicked" with thiosemicarbazone ligands can be used successfully for the analysis of Hg(II) ions from water samples. Moreover, the modified electrodes showed a very good reproducibility, stability over time and reusability, and can therefore be employed as sensitive and selective sensors for Hg(II) ion analysis in environmental samples.
Revista de Chimie
Several catanionic organogelators derived from 1,3 :2,4-bis-O-(p-aminobenzylidene)-D-sorbitol (p-... more Several catanionic organogelators derived from 1,3 :2,4-bis-O-(p-aminobenzylidene)-D-sorbitol (p-NH2-DBS) and hydroxy derivatives of natural fatty acids were synthesized, characterized and their gelation ability was evaluated. SEM observations of the xerogels formed by association of 1,3 :2,4-bis-O-(p-aminobenzylidene)-D-sorbitol and 12-hydroxystearic acid showed important modifications in the morphology and depend upon the nature of solvent as compared with the xerogels formed by each individual organogelator.
Biochemical composition and physical appearance of linseed oil determine the quality of the oils ... more Biochemical composition and physical appearance of linseed oil determine the quality of the oils extracted for various industrial uses. The behavior of 11 genotypes of linseed from south of the country was analyzed, on the basis of multiannual testing in competitive crops, in order to study the influence of climatic conditions on agronomic characteristics and physicochemical properties of linseed. Genotype-environment interaction has proven to be very significant for production potential. As yield potential, the brown seed genotypes were highlighted, these recording the highest yields between 2390 and 2430 kg/ha oil content. As oil content, the both yellow and brown seed genotypes were emphasized. The oil content of analyzed genotypes ranged between 43.05 and 47.22%. The unsaturated fatty acids: oleic (14.4 to 22.07%), linoleic (14.88 to 18.48%) and linolenic (49.97 to 60.68%) which determine the quality and sicativity of linseed oil were tested. As part of breeding material, there ...
spectroscopy (IR), based on trans specific bonds absorption at 966 cm -1 (while the absorption of... more spectroscopy (IR), based on trans specific bonds absorption at 966 cm -1 (while the absorption of the cis bonds appears at 724 cm -1 ). Based on the measurement of the absorption band at 966 cm -1 , a calibration curve was obtained. The results were compared with those obtained by gas chromatography-mass spectrometry technique (GC-MS) used as reference method to quantify the trans fats. The results obtained demonstrated that trans fatty acids formation in vegetable oils during heating, is closely related to process temperature and time and also that trans fatty acids can only be formed under severe conditions.
Seven species of fish (salmon, mackerel, catfish, two species of phytophagous fish, cod liver, br... more Seven species of fish (salmon, mackerel, catfish, two species of phytophagous fish, cod liver, bream) were studied for their oil fatty acids composition. Crude fish oils were obtained by standard Soxlet extraction method. Identification and quantitative measurement of fish oils fatty acids were carried out by gas chromatography coupled with mass spectrometry and by H-NMR spectroscopy. Fourteen individual fatty acids were identified using GC-MS technique. GC-MS was applied on fatty acids methyl esters. Identification of fatty acids from oil samples was made using a standard mixture of 37 fatty acid methyl esters. H-NMR spectroscopy gives information about classes of unsaturated and saturated fatty acids. By this method can also determine the ω-3 and docosahexaenoic fatty acid content. Using both analytical methods, polyunsaturated fatty acids important for human health (eicosapentaenoic and docosahexaenoic acids) were identified and quantified.
MARIA-CRISTINA TODASCA1*, LAURA FOTESCU2, NICOLETA-AURELIA CHIRA1, CALIN DELEANU3, SORIN ROSCA1 1... more MARIA-CRISTINA TODASCA1*, LAURA FOTESCU2, NICOLETA-AURELIA CHIRA1, CALIN DELEANU3, SORIN ROSCA1 1University Politehnica Bucharest, Faculty of Applied Chemistry and Material Science, „C. Nenitescu” Organic Chemistry Department, 1-7 Polizu St., 011061, Bucharest, Romania 2 Researches and Development Institute for Viticulture and Vineyard, Valea Calugareasca, Romania 3 Romanian Academy, Center of Organic Chemistry “C. D. Nenitzescu”, 202B Spl. Independentei, 060023, Bucharest, Romania
Această lucrare prezintă utilizarea spectroscopiei de rezonanţă magnetică nucleară de proton si c... more Această lucrare prezintă utilizarea spectroscopiei de rezonanţă magnetică nucleară de proton si cromatografia de gaze pentru determinarea indicilor de calitate ai uleiurilor vegetale. Pe baza datelor 1 H-RMN, s-au dedus ecuaţii chemometrice care permit calcularea masei moleculare medii si indicilor de iod si de saponificare ai uleiurilor vegetale. Aceste rezultate au fost comparate cu valorile obţinute prin metodele standard de analiză si s-au dovedit a fi in concordanţă cu acestea. This work presents the use of proton nuclear magnetic resonance spectroscopy and gas-chromatography for the determination of quality indices of vegetable oils. Based on the 1 H-NMR data, chemometric equations were developed, leading to the computation of the average molecular weight, iodine and saponification indices of vegetable oils. The results were compared with those obtained by standard methods and proved to be in agreement.
Nuclear magnetic resonance (NMR) spectroscopy coupled with Principal Components Analysis (PCA) ch... more Nuclear magnetic resonance (NMR) spectroscopy coupled with Principal Components Analysis (PCA) chemometrical method were used to characterize juices and wines obtained from four types of forest fruits (strawberries, blackberries, raspberries and blueberries) and three varieties of grapes (Muscat Ottonel, Fetească Albă and Burgund). H-NMR spectroscopy provided two sets of data that can be used to classify juices and wines. The first set of data used in PCA was the absolute concentrations of compounds identified in juices and wines. The second set of data was obtained by transforming the H-NMR spectra into strings of numerical values by integrating relevant spectral windows in steps of 0.2 ppm. Those sets of data were further used to discriminate juices and wines according to the row material.
We report here the synthesis of an azo dye bearing monomer by grafting 4-hydroxy-4’-nitroazobenze... more We report here the synthesis of an azo dye bearing monomer by grafting 4-hydroxy-4’-nitroazobenzene onto the epoxidized linseed oil (ELO) backbone thus leading to coloured epoxidised compounds. The reaction product was further crosslinked with ELO under acidic conditions (BF3·Et2O), obtaining a coloured crosslinked material, which was characterised by FTIR spectroscopy and thermo gravimetric analyses. Prior to the azo dye functionalization, the starting material (ELO) has been characterized by spectroscopic (1H-NMR and FTIR) methods in order to chemometrically determine the chemical composition and the epoxide amount per gram of ELO. The chemometric approach is exhaustively presented.
2 "Gheorghe Ionescu-Siseoti" Academy of Agricultural and Forestry Sciences, 61 Maraoti ... more 2 "Gheorghe Ionescu-Siseoti" Academy of Agricultural and Forestry Sciences, 61 Maraoti Blv, 011464, Bucharest, Romania This paper presents the use of gas-chromatographic technique of compositional analysis of oils for the examination of the efficiency of different fertilization treatments applied to sunflower and rapeseed. Two series of oilseeds (sunflower and rapeseed) simultaneously grown in the same geographic aria and of the same variety but treated with different fertilizers have been analyzed. The efficiency of the agrotechnical treatments was determined on the basis of the oilseed production increase (kg/ha), oil production increase (kg/ha) and of some quality indices of oils (ω-3 fatty acid content, ω-3/ ω-6 ratio).
The fatty acid composition of vegetable oils is the main factor influencing their properties, con... more The fatty acid composition of vegetable oils is the main factor influencing their properties, concerning both nutrition [1, 2] and exploitation as raw materials for oleochemistry [3-6]. In recent years, interest of scientist to develop new and efficient methods for the determination of the fatty acid profile of different kind of samples (edible oils [7], lipid extracts from different human [8] or animal tissues [9], etc.), has increased, being partially fed by the general trend in the chemical literature concerning the food authenticity assessment. Among the most envisaged physical methods of analysis, gas-chromatography is by far the most popular [10], but 1H-NMR spectroscopy is considered an interesting alternative [11, 12]. The present paper aims to exploit the potential of the 1H-NMR spectroscopy regarding structural and compositional information applied to vegetable oils field, as well as its non-destructive nature and mild analysis conditions which does not require chemical tr...
Journal of Food Measurement and Characterization
The present study aims at optimising the oil extraction from Dragon’s head ( Lallemantia iberica ... more The present study aims at optimising the oil extraction from Dragon’s head ( Lallemantia iberica ) seeds using response surface methodology. For this purpose, the working conditions (solid/liquid ratio, ultrasound intensity and extraction time) were varied in a series of experiments to determine the optimum extraction conditions, which were further verified through an independent extraction experiment. The experiments were conducted using ultrasound-assisted extraction (UAE) technique. The maximum yield obtained for UAE extraction efficiency under optimal conditions was 97.02%, taking the Soxhlet technique as a reference (corresponding to an oil content of 39.73 g/100 g dry seeds). The operation conditions for maximum extraction efficiency were: 1/16 (g/mL) solid/liquid ratio, 13.77 (W/cm 2 ) ultrasound intensity and 12.5 min extraction time.
Sustainability
Cnicus benedictus fruits were used as raw material to extract oil, and the resulting oil was conv... more Cnicus benedictus fruits were used as raw material to extract oil, and the resulting oil was converted into biodiesel. Two extraction methods were tested: batch extraction, and ultrasound assisted extraction. Response surface methodology was considered for the optimization of the process efficiency. The selected key independent variables were temperature, extraction time, and solid/liquid ratio for batch extraction and ultrasound intensity, temperature, and extraction time for the ultrasound assisted extraction, respectively. The optimal working conditions are different for the two extraction techniques, with respect to temperature, solid/liquid ratio, and extraction time, respectively, leading to higher extraction efficiency in the case of the ultrasound-assisted extraction. Cnicus benedictus oil obtained under the optimal extraction conditions was further esterified with methanol under acid catalysis to yield biodiesel. The biodiesel was characterized through 1H-NMR and the main f...
NICOLETA-AURELIA CHIRA1*, MARIA-CRISTINA TODASCA1, GABRIELA PAUNESCU2, IONICA DAVID3, NICULINA IO... more NICOLETA-AURELIA CHIRA1*, MARIA-CRISTINA TODASCA1, GABRIELA PAUNESCU2, IONICA DAVID3, NICULINA IONESCU3, MARIA STANCIU3, SORIN ROSCA1 1 “Politehnica” University of Bucharest, Organic Chemistry Department, 1-7 Polizu Str., Bucharest, 011061, Romania. 2 Agricultural Research and Development Station aimnic, Dept of Plant Breeding, Craiova, Romania. 3 National Agricultural Research and Development Institute (NARDI), 915200, Fundulea, 1 Nicolae Titulescu Str., Cãlãraoi County, Romania
MIHAELA MIHALACHE1, AURELIA BRATU1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA T... more MIHAELA MIHALACHE1, AURELIA BRATU1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA TODASCA1, SORIN ROSCA1 1 University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, “Costin D. Nenitzescu” Organic Chemistry Department, 1-7 Polizu Str., 011061, Bucharest, Romania 2 Romanian Academy, Organic Chemistry Center “Costin D. Nenitzescu” 202B Splaiul Independentei, 060023, Bucharest, Romania
MARIA-CRISTINA TODASCA1* LAURA FOTESCU2, FULVIA ANCUTA HINCU3, ANAMARIA HANGANU1, NICOLETA-AURELI... more MARIA-CRISTINA TODASCA1* LAURA FOTESCU2, FULVIA ANCUTA HINCU3, ANAMARIA HANGANU1, NICOLETA-AURELIA CHIRA1, SORIN ROSCA1 1 University Politehnica Bucharest, Faculty of Applied Chemistry and Material Science, „C. Nenitescu” Organic Chemistry Department, 1-7 Polizu Str., 011061, Bucharest, Romania 2 Researches and Development Institute for Viticulture and Vineyard, Valea Cãlugãreasca, Romania 3 Institute of Food Bioresources, 6 Dinu Vintila Str., 021102, Bucharest, Romania
AURELIA BRATU1, MIHAELA MIHALACHE1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA T... more AURELIA BRATU1, MIHAELA MIHALACHE1*, ANAMARIA HANGANU2, NICOLETA-AURELIA CHIRA1, MARIA-CRISTINA TODASCA1, SORIN ROSCA1 1 University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, “Costin D. Nenitzescu” Organic Chemistry Department, 1-7 Polizu Str., 011061, Bucharest, Romania 2 Romanian Academy, Organic Chemistry Center “Costin D. Nenitzescu” 202B Splaiul Independentei, 060023, Bucharest, Romania
The fermentations of some Romanian grape musts with Saccharomyces cerevisiae yeast were studied u... more The fermentations of some Romanian grape musts with Saccharomyces cerevisiae yeast were studied under different conditions: natural fermentations (without additional yeast), induced fermentation using different amounts of selected yeasts and industrial fermentation. The wines fermentations have been daily monitored using 1H nuclear magnetic resonance (1H-NMR) spectroscopy. Based on the 1H-NMR spectroscopy and applying multivariate statistical analysis, we studied the changes in the chemical compositions of wines depending on the alcoholic fermentation conditions establishing the influence of yeast used in the process.
Sensors and Actuators B: Chemical
Sensors and Actuators B: Chemical
Abstract The synthesis of a series of thiosemicarbazone ligands bearing azido groups, which were ... more Abstract The synthesis of a series of thiosemicarbazone ligands bearing azido groups, which were further immobilized on the surface of phenylethynyl-functionalized glassy carbon (GC) electrodes through a Cu(I)-catalyzed "click" reaction is reported. The modified electrodes presented a remarkable selectivity towards Hg(II) among other metal ions. Under optimized conditions and using the accumulation at open circuit-anodic stripping technique, detection limits below nanomolar level were obtained for Hg(II). Further, we demonstrated that GC electrodes "clicked" with thiosemicarbazone ligands can be used successfully for the analysis of Hg(II) ions from water samples. Moreover, the modified electrodes showed a very good reproducibility, stability over time and reusability, and can therefore be employed as sensitive and selective sensors for Hg(II) ion analysis in environmental samples.
Revista de Chimie
Several catanionic organogelators derived from 1,3 :2,4-bis-O-(p-aminobenzylidene)-D-sorbitol (p-... more Several catanionic organogelators derived from 1,3 :2,4-bis-O-(p-aminobenzylidene)-D-sorbitol (p-NH2-DBS) and hydroxy derivatives of natural fatty acids were synthesized, characterized and their gelation ability was evaluated. SEM observations of the xerogels formed by association of 1,3 :2,4-bis-O-(p-aminobenzylidene)-D-sorbitol and 12-hydroxystearic acid showed important modifications in the morphology and depend upon the nature of solvent as compared with the xerogels formed by each individual organogelator.