Nicoleta Matei | Ovidius University of Constanta (original) (raw)
Papers by Nicoleta Matei
Environmental Engineering and Management Journal, 2004
Analyses of plants render important information in toxicological and environmental investigations... more Analyses of plants render important information in toxicological and environmental investigations since plants are a very significant link in the trophic chain. The aim of this study was to analyze quantitatively the distribution of heavy metals and ascorbic acid in Allium plants: Allium sativum L. (garlic) and Allium cepa L. (onion). Heavy metals accumulation in garlic and onion was quantified by flame atomic absorption spectrometry (FAAS) after the chemical mineralization of the samples with nitric acid and hydrogen peroxide in a Digesthal device. To determinate of vitamin C we used a titrimetric method with potassium brommat-bromide solution in acid medium, when vitamin C is oxidized to dehidroascorbic acid by bromine. Our results indicate a high concentration of vitamin C in leaves of the studied Allium plants.
… Grigore Popa Umanist desavârsit Om al …, 2004
Page 65. Analele Universităţii din Bucureşti–Chimie, Anul XIII (serie nouă), vol. I-II, pag. 65-6... more Page 65. Analele Universităţii din Bucureşti–Chimie, Anul XIII (serie nouă), vol. I-II, pag. 65-68 Copyright© 2004 Analele Universităţii din Bucureşti DETERMINAT ION OF VITAMIN CF ROM SOME NATURAL PRODUCTS PRESERVED ...
Ovidius University Annals of Chemistry, 2015
Ovidius University Annals of Chemistry, 2015
Ovidius University Annals of Chemistry, 2015
Ovidius University Annals of Chemistry, 2015
Revista de Chimie -Bucharest- Original Edition-
During the last years, following the general trend of using what nature is directly offering, bee... more During the last years, following the general trend of using what nature is directly offering, bee products got an increasing importance as essential natural resources in promoting healthy food. The objective of this study was to determine the ascorbic acid and the contents of trace essential elements (Cr, Fe, Mn, Ni). Ascorbic acid was first known to prevent scurvy. This
Analele Universitatii "Ovidius" Constanta - Seria Chimie, 2012
Ascorbic acid (AA) is a powerful antioxidant naturally present in many foods, especially fruits a... more Ascorbic acid (AA) is a powerful antioxidant naturally present in many foods, especially fruits and vegetables, which play an important role in the prevention of infectious diseases. It is important in processes of oxidation and reduction in human organism, participating in several metabolic reactions. A simple method for the ascorbic acid (Vitamin C) in some fruit type utilizing a titrimetric method with potassium bromide is described. To observe source of Vitamin C in these fruits and how easy it's losing once with the vegetation period, we determine Vitamin C concentration from: leaves, tails, green fruits, respectively from fruits. The precision of the determination of Vitamin C was evaluated and it was found that the recovery of ascorbic acid was 97%. The precision of the method is good and the recovery of the analyte is nearly quantitative.
Two simple procedures for the determination of ascorbic acid (Vitamin C) content in a Vitamin C t... more Two simple procedures for the determination of ascorbic acid (Vitamin C) content in a Vitamin C tablet are proposed: conductometry and titrimetric method with potassium bromat-bromide solution in the acid medium. The procedures have been applied to the analysis of locally commercial Vitamin C tablet samples. The variations of Vitamin C concentration were studied in formation of temperature. For the kinetic study was determinate the rate constant, the half-time and the activation energy for vitamin C.
The aim of this work is to determine the metal contents from different components of a fruit (pul... more The aim of this work is to determine the metal contents from different components of a fruit (pulp, film and peel). The determinations of metal's traces are very important because they are involved in biological cycles and indicate high toxicity. Analyses were performed using the flame atomic absorption spectrometry (Shimadzu AA 6200), after the chemical mineralization of the sample with a Digesdahl device. The obtained values are in good agreement with the literature data.
The Annals of the, 2009
... And Thermal Energy Distribution Field. Author info | Abstract | Publisher info | Download inf... more ... And Thermal Energy Distribution Field. Author info | Abstract | Publisher info | Download info | Related research | Statistics. Author Info. Nicoleta Cristina MATEI () (Romanian-American University, Bucharest, Romania) Abstract. ...
Analytical Methods, 2013
ABSTRACT A simple, fast and sensitive high-performance liquid chromatography/ electrospray ioniza... more ABSTRACT A simple, fast and sensitive high-performance liquid chromatography/ electrospray ionization-mass spectrometry method is described and validated in terms of linearity, accuracy/recovery and reproducibility, as well as limit of detection for the determination of ascorbic acid from grape (Vitis vinifera L.) samples from Murfatlar vineyard. Good linearity (correlation factor > 0.9970) was achieved in the concentration range 0.5-15 μg mL-1 for AA in acetic acid 0.1% solution. The obtained RSD values (below 5%) indicated excellent repeatability of the proposed method. The limit of detection was 0.32 μg mL-1 while the recovery ranged between 96.86 and 102.41%. The advantages of the method are: small amounts of sample and solvents, short analysis time and minimum steps for sample preparation.
univ-ovidius.ro
... Kinetic study of ascorbic acid degradation from grapes Nicoleta MATEI*a, Alina SOCEANUa, Simo... more ... Kinetic study of ascorbic acid degradation from grapes Nicoleta MATEI*a, Alina SOCEANUa, Simona DOBRINASa, and Vasile MAGEARUb ... GB Golubitskii, EV Budko, EM Basova, AV Kostarnoi and VM Ivanov, Journal of Analitical Chemistry, 62, 8, 742-747, (2007) [18]. ...
Analele Universitatii "Ovidius" Constanta - Seria Chimie, 2014
Environmental Engineering and Management Journal, 2004
Analyses of plants render important information in toxicological and environmental investigations... more Analyses of plants render important information in toxicological and environmental investigations since plants are a very significant link in the trophic chain. The aim of this study was to analyze quantitatively the distribution of heavy metals and ascorbic acid in Allium plants: Allium sativum L. (garlic) and Allium cepa L. (onion). Heavy metals accumulation in garlic and onion was quantified by flame atomic absorption spectrometry (FAAS) after the chemical mineralization of the samples with nitric acid and hydrogen peroxide in a Digesthal device. To determinate of vitamin C we used a titrimetric method with potassium brommat-bromide solution in acid medium, when vitamin C is oxidized to dehidroascorbic acid by bromine. Our results indicate a high concentration of vitamin C in leaves of the studied Allium plants.
… Grigore Popa Umanist desavârsit Om al …, 2004
Page 65. Analele Universităţii din Bucureşti–Chimie, Anul XIII (serie nouă), vol. I-II, pag. 65-6... more Page 65. Analele Universităţii din Bucureşti–Chimie, Anul XIII (serie nouă), vol. I-II, pag. 65-68 Copyright© 2004 Analele Universităţii din Bucureşti DETERMINAT ION OF VITAMIN CF ROM SOME NATURAL PRODUCTS PRESERVED ...
Ovidius University Annals of Chemistry, 2015
Ovidius University Annals of Chemistry, 2015
Ovidius University Annals of Chemistry, 2015
Ovidius University Annals of Chemistry, 2015
Revista de Chimie -Bucharest- Original Edition-
During the last years, following the general trend of using what nature is directly offering, bee... more During the last years, following the general trend of using what nature is directly offering, bee products got an increasing importance as essential natural resources in promoting healthy food. The objective of this study was to determine the ascorbic acid and the contents of trace essential elements (Cr, Fe, Mn, Ni). Ascorbic acid was first known to prevent scurvy. This
Analele Universitatii "Ovidius" Constanta - Seria Chimie, 2012
Ascorbic acid (AA) is a powerful antioxidant naturally present in many foods, especially fruits a... more Ascorbic acid (AA) is a powerful antioxidant naturally present in many foods, especially fruits and vegetables, which play an important role in the prevention of infectious diseases. It is important in processes of oxidation and reduction in human organism, participating in several metabolic reactions. A simple method for the ascorbic acid (Vitamin C) in some fruit type utilizing a titrimetric method with potassium bromide is described. To observe source of Vitamin C in these fruits and how easy it's losing once with the vegetation period, we determine Vitamin C concentration from: leaves, tails, green fruits, respectively from fruits. The precision of the determination of Vitamin C was evaluated and it was found that the recovery of ascorbic acid was 97%. The precision of the method is good and the recovery of the analyte is nearly quantitative.
Two simple procedures for the determination of ascorbic acid (Vitamin C) content in a Vitamin C t... more Two simple procedures for the determination of ascorbic acid (Vitamin C) content in a Vitamin C tablet are proposed: conductometry and titrimetric method with potassium bromat-bromide solution in the acid medium. The procedures have been applied to the analysis of locally commercial Vitamin C tablet samples. The variations of Vitamin C concentration were studied in formation of temperature. For the kinetic study was determinate the rate constant, the half-time and the activation energy for vitamin C.
The aim of this work is to determine the metal contents from different components of a fruit (pul... more The aim of this work is to determine the metal contents from different components of a fruit (pulp, film and peel). The determinations of metal's traces are very important because they are involved in biological cycles and indicate high toxicity. Analyses were performed using the flame atomic absorption spectrometry (Shimadzu AA 6200), after the chemical mineralization of the sample with a Digesdahl device. The obtained values are in good agreement with the literature data.
The Annals of the, 2009
... And Thermal Energy Distribution Field. Author info | Abstract | Publisher info | Download inf... more ... And Thermal Energy Distribution Field. Author info | Abstract | Publisher info | Download info | Related research | Statistics. Author Info. Nicoleta Cristina MATEI () (Romanian-American University, Bucharest, Romania) Abstract. ...
Analytical Methods, 2013
ABSTRACT A simple, fast and sensitive high-performance liquid chromatography/ electrospray ioniza... more ABSTRACT A simple, fast and sensitive high-performance liquid chromatography/ electrospray ionization-mass spectrometry method is described and validated in terms of linearity, accuracy/recovery and reproducibility, as well as limit of detection for the determination of ascorbic acid from grape (Vitis vinifera L.) samples from Murfatlar vineyard. Good linearity (correlation factor > 0.9970) was achieved in the concentration range 0.5-15 μg mL-1 for AA in acetic acid 0.1% solution. The obtained RSD values (below 5%) indicated excellent repeatability of the proposed method. The limit of detection was 0.32 μg mL-1 while the recovery ranged between 96.86 and 102.41%. The advantages of the method are: small amounts of sample and solvents, short analysis time and minimum steps for sample preparation.
univ-ovidius.ro
... Kinetic study of ascorbic acid degradation from grapes Nicoleta MATEI*a, Alina SOCEANUa, Simo... more ... Kinetic study of ascorbic acid degradation from grapes Nicoleta MATEI*a, Alina SOCEANUa, Simona DOBRINASa, and Vasile MAGEARUb ... GB Golubitskii, EV Budko, EM Basova, AV Kostarnoi and VM Ivanov, Journal of Analitical Chemistry, 62, 8, 742-747, (2007) [18]. ...
Analele Universitatii "Ovidius" Constanta - Seria Chimie, 2014