Search results for " gas chromatography"

Quartz-capillary gas chromatography of chlorinated phenols and catechols

1983

The gas chromatography of all chlorinated phenols and catechols on a non-polar SE-30 quartz-capillary column has been studied. The relative retention times of the individual components are given and the elution order is discussed. All of the chlorophenols and chlorocatechols can be separated under appropriate operating conditions but simultaneous determination of all the compounds studied resulted in overlapping peaks. Theortho-effect in catechols is stronger than that in phenols. A different order of elution for the compounds studied to that of the corresponding acetate esters is found. Generally, longer retention times for the latter are observed.

1984

By means of data from critical demixing and vapour pressure measurements and by inverse gas chromatography, including the results of published light scattering measurments, a consistent picture is obtained for the entire dependence of the Flory-Huggins parameter χ on the weight fraction w2 of the polymer and on the temperature T for the system tert-butyl acetate/polystyrene. Within the entire T-range (ca. 0°C – 140°C), χ increases stronger than exponentially with w2, the rise being the larger the larger χH (the enthalpy contribution to χ) becomes in the limit of infinite dilution. At sufficiently high temperatures (≳ 50°C), χH changes its sign from negative to positive as w2 is raised. This…

The gas chromatography/mass spectrometry can be used for dose estimation in irradiated pork

2009

Abstract Food safety can be improved using ionizing radiation to reduce food spoilage and to extend its shelf life. The gas chromatography/mass spectrometry (GC/MS) has been validated by the European Community as a powerful method to identify irradiated food containing fat. The preliminary goals of our research were: (i) to set up this method, based on the detection of radiation induced 2-dodecylcyclobutanones (2-DCB) in pork muscle samples and (ii) to check the microbiological efficacy of the treatment. The main objective was to render the GC/MS a quantitative technique for dose estimation, through the measurement of the 2-DCB concentration in the irradiated sample. Our results show that t…

Volatile flavour components of ocimum basilicum var. hispidum (lam.) Chiov.

1991

The volatile components obtained by steam-distillation ofOcimum basilicum var. hispidum (Lam.) Chiov. (Labiatae) were analysed by gas chromatography (GC) and gas chromatography—mass spectrometry (GC-MS). A total of 21 compounds, representing ca 90% of the total oil, were identified. The identity of the main component (82%), dihydrotagetone, was confirmed by 1H- and 13C-NMR spectroscopy. This is the first report of this compound in the genus Ocimum.

Determination of 60 Migrant Substances in Plastic Food Contact Materials by Vortex-Assisted Liquid-Liquid Extraction and GC-Q-Orbitrap HRMS

2021

A GC-HRMS analytical method for the determination of 60 migrant substances, including aldehydes, ketones, phthalates and other plasticizers, phenol derivatives, acrylates, and methacrylates, in plastic food contact materials (FCM) has been developed and validated. The proposed method includes migration tests, according to Commission Regulation (EU) 10/2011, using four food simulants (A, B, C, and D1), followed by vortex-assisted liquid–liquid extraction (VA-LLE) and GC-Q-Orbitrap HRMS analysis in selected ion monitoring (SIM) mode, with a resolving power of 30,000 FWHM and a mass accuracy ≤5 ppm. The method was validated, showing satisfactory linearity (R2 ≥ 0.98 from 40 to 400 …

Thermodynamic Interaction Parameters of Tetra-n-undecylcalix[4]resorcinarenes with Selected Solvents Studied by Inverse Gas Chromatography

2004

The basic thermodynamic parameters, characterising intermolecular interactions of tetra-n-undecylcalix[4]resorcinarene and its octaacetate derivative with simple organic solutes, were calculated by using the inverse gas chromatography method. Free energy, enthalpy and entropy of sorption were determined.

Reuse of Food Waste: The Chemical Composition and Health Properties of Pomelo (Citrus maxima) Cultivar Essential Oils

2022

The aim of the present study is to investigate the chemical profile, antioxidant activity, carbohydrate-hydrolysing enzyme inhibition, and hypolipidemic effect of essential oils (EOs) extracted from Sicilian Citrus maxima (pomelo) flavedo. Using gas-chromatography-mass spectrometry analysis (GC-MS) we analysed the Eos of five cultivars of C. maxima, namely, ‘Chadock’, ‘Maxima’, ‘Pyriformis’, ‘Terracciani’, and ‘Todarii’, and their blends. The antioxidant activity was performed by using a multi-target approach using 2,2′-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic acid (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reduc…