Search results for "Gas-chromatography"
showing 10 items of 16 documents
Different sample treatment approaches for the analysis of T-2 and HT-2 toxins from oats-based media.
2010
A LC-DAD method is proposed for the determination of the T-2 and HT-2 toxins in cultures of Fusarium langsethiae in oat-based and other in vitro media. Test media consisted of freshly prepared milled oats to which T-2 and HT-2 toxin stock solutions were added. Different mixtures of extraction solvent (acetonitrile:water and methanol water), extraction times (30', 60' or 90') and drying methods were investigated. Results showed that extraction with methanol: water (80:20, v/v) for 90 min, drying with N-2 and subsequent analysis by LC-DAD was the fastest and most user friendly method for detecting HT-2 and T-2 toxins production by F. langsethiae strains grown on oat-based media at levels of 0…
Flavouring Extra-Virgin Olive Oil with Aromatic and Medicinal Plants Essential Oils Stabilizes Oleic Acid Composition during Photo-Oxidative Stress
2021
Essential oils (EOs) from medicinal and aromatic plants (MAPs) are well-known as natural antioxidants. Their addition to extra-virgin olive oil (EVOO) can contribute to reducing fat oxidation. The main aim of this study was to improve both food shelf-life and aromatic flavour of EVOO, adding different EOs of Sicilian accessions of common sage, oregano, rosemary and thyme. The morphological and production characteristics of 40 accessions of MAPs were preliminarily assessed. EOs from the most promising accessions of MAPs were analysed by gas-chromatography and mass spectrometry. Photo-oxidative studies of the EOs were carried out and the determination of the EVOO fatty acids obtained from 4 I…
Determination of Selected Phthalates by Gas Chromatography–Mass Spectrometry in Personal Perfumes
2015
A simple and fast method is proposed to analyze commercial personal perfumes. Our method includes measurement of phthalates, known to be major sources of endocrine disruptor chemicals (EDC), which originate from the less volatile fraction of perfumes. The quantification of phthalates were carried out directly with no sample preparation required on 30 samples of commercial products using gas chromatography and mass spectrometry (GC-MS) as a detector. The total concentrations of 15 investigated compounds ranged from 17 to 9650 mg/L with an average of 2643 mg/L. The highest total concentration was found in cologne. Diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalat…
Identification of organic compounds in fictile unguentaria from two Sicilian necropolis of Greek age (5th century, b.c.) by GC-MS analysis.
2007
A study to obtain more knowledge on funeral set in Greek age, (5th Century, b.C.) was carried out on thirteen ancient unguentaria, small vessels used as containers of balms or ointments, founded in two different Sicilian necropolis: Adranon and Hymera. Every find was subjected to three extractions by increasing polarity solvents. All crude extracts, unsaponifiables and methyl esters of saponifiable fraction were analysed by GC-MS. Analysis showed difference between two groups of finds: the unguentaria from Adranon show abundant traces of lipids used in balm making, while those from Hymera resulted empty and buried for ritual purpose. Even if in the two towns, flourished in the same period, …
Determination of pesticides and their degradation products in soil: critical review and comparison of methods
2004
18 páginas, 5 figuras, 5 tablas.
Odorant Metabolism Analysis by an Automated Ex Vivo Headspace Gas-Chromatography Method
2015
International audience; In the olfactory epithelium (OE), odorant metabolizing enzymes have the dual function of volatile component detoxification and active clearance of odorants from the perireceptor environment to respectively maintain the integrity of the tissues and the sensitivity of the detection. Although emphasized by recent studies, this enzymatic mechanism is poorly documented in mammals. Thus, olfactory metabolism has been characterized mainly in vitro and for a limited number of odorants. The automated ex vivo headspace gas-chromatography method that was developed here was validated to account for odorant olfactory metabolism. This method easily permits the measurement of the f…
Phosphoglycerate Kinases Are Co-Regulated to Adjust Metabolism and to Optimize Growth
2017
[EN] In plants, phosphoglycerate kinase (PGK) converts 1,3-bisphosphoglycerate into 3-phosphoglycerate in glycolysis but also participates in the reverse reaction in gluconeogenesis and the Calvin-Benson cycle. In the databases, we found three genes that encode putative PGKs. Arabidopsis (Arabidopsis thaliana) PGK1 was localized exclusively in the chloroplasts of photosynthetic tissues, while PGK2 was expressed in the chloroplast/plastid of photosynthetic and nonphotosynthetic cells. PGK3 was expressed ubiquitously in the cytosol of all studied cell types. Measurements of carbohydrate content and photosynthetic activities in PGK mutants and silenced lines corroborated that PGK1 was the phot…
The molecular identification of organic compounds in the atmosphere: state of the art and challenges.
2015
SSCI-VIDE+ATARI:CARE+BNO:BDA; International audience
The caramel flavour: impacts of the volatile and the non-volatile fraction on perception
2013
The aim of this thesis was to investigate the impact of the volatile odorant fraction and the non-volatile fraction on the perception of caramel flavour. The first step focused on the analytical characterization of the volatile odorant fraction of caramel using Gas Chromatography coupled to Olfactometry (GC/O), GC/Mass Spectrometry (GC/MS) and heart-cutting MDGC/MS/O. Results highlighted the presence of more than one hundred compounds and demonstrated the complexity of the caramel volatile fraction. The objective of the second step was to understand the contribution of odorant compounds identified to the caramel aroma typicality. Literature shows that odour intensity is not sufficient to ev…
Understanding the role of saliva in aroma release from wine by using static and dynamic headspace conditions.
2014
The aim of this work was to determine the role of saliva in wine aroma release by using static and dynamic headspace conditions. In the latter conditions, two different sampling points (t = 0 and t = 10 min) corresponding with oral (25.5 °C) and postoral phases (36 °C) were monitored. Both methodologies were applied to reconstituted dearomatized white and red wines with different nonvolatile wine matrix compositions and a synthetic wine (without matrix effect). All of the wines had the same ethanol concentration and were spiked with a mixture of 45 aroma compounds covering a wide range of physicochemical characteristics at typical wine concentrations. Two types of saliva (human and artifici…