Search results for "Gas chromatography–mass spectrometry"
showing 10 items of 199 documents
Determination of terpene alcohols in Sicilian Muscat wines by HS-SPME-GC-MS.
2013
Muscat is a grape family used to obtain several sweet, aromatic white dessert wines common in the Mediterranean area. Currently, three Sicilian cultivars (all classified DOC) are known: 'Moscato di Siracusa' the oldest and very rare today; 'Moscato di Noto', a modern derivative of the first and finally 'Moscato di Pantelleria', now the most common. This study concerns the volatile profile of 15 different Sicilian Muscat wines produced in different years using HS-SPME-GC-MS. In particular, four fundamental terpene alcohols (linalool, geraniol, nerol and citronellol) were considered. The principal aim was to study the evolution of aromatic compounds in wine during aging, and the information o…
Essential oil components of orange peels and antimicrobial activity
2016
In this study, the orange peel of 12 cultivars of Citrus sinensis from central-eastern Sicily was employed to obtain essential oils and extracts. The ones were extracted through steam distillation, the others through extraction in hexane. Chemical constituents were evaluated in terms of qualitative and quantitative analyses by gas chromatography/mass spectrometry. Fifty-four components were identified in the steam essential oils and 44 in the extracts. In all the cultivars, the main component is d-limonene (73.9–97%); discrete percentages of linalool, geraniol and nerol were also found. Cluster analysis based on essential oils composition showed a certain degree of affinity between cultivar…
Identification and Evaluation of Hazardous Pyrolysates in Bio-Based Rigid Polyurethane-Polyisocyanurate Foam Smoke
2021
In this study, rigid polyurethane (PU) and polyisocyanurate (PIR) foam samples made from renewable material (tall oil fatty acid) based polyols were analyzed by pyrolysis gas chromatography mass spectrometry (Py-GC/MS) to obtain information about the full relative smoke content, with a focus on substance identification by their functional groups and hazardousness. The relative content of gaseous products produced during the thermal degradation was evaluated between the two samples, differenced by their assigned isocyanate (NCO) index value—150 and 300. The main thermal degradation components of the rigid PU-PIR foam were found to originate from the decomposition of isocyanate, primarily for…
Characterization of Odor-Active Compounds in Aromatic Caramel by GC-Olfactometry and GC-Mass Spectrometry
2014
The aim of this study was to characterize odor-active compounds and sensory properties of four aromatic caramels. The volatile fraction was isolated by solvent assisted flavor evaporation (SAFE) and analyzed by GC/MS and GC/O with the detection frequency method. Furthermore, descriptive sensory profiles were performed with a panel of 10 trained assessors. Of the 77 odorant areas detected (detection frequency≥33%), 40 were associated to identified molecules. GC/O data were correlated to sensory attributes by partial least squares regression (PLSR). Oxygenated heterocycles, cyclopentenone derivatives, and carboxylic acids appeared as the most important contributors in caramel aroma.
Dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry for the determination of nitro musks in surface water and w…
2011
A new, simple, fast and high sensitive analytical method based on dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of nitro musks in surface water and wastewater samples is presented. Different parameters, such as the nature and volume of both the extraction and disperser solvents and the ionic strength and pH of the aqueous donor phase, were optimized. Under the selected conditions (injection of a mixture of 1 mL of acetone as disperser solvent and 50 μL of chloroform as extraction solvent, no salt addition and no pH adjustment) the figures of merit of the proposed DLLME-GC-MS method were evaluated.…
Dispersive solid-phase extraction based on oleic acid-coated magnetic nanoparticles followed by gas chromatography-mass spectrometry for UV-filter de…
2011
Abstract A sensitive analytical method to concentrate and determine extensively used UV filters in cosmetic products at (ultra)trace levels in water samples is presented. The method is based on a sample treatment using dispersive solid-phase extraction (dSPE) with laboratory-made chemisorbed oleic acid-coated cobalt ferrite (CoFe 2 O 4 @oleic acid) magnetic nanoparticles (MNPs) as optimized sorbent for the target analytes. The variables involved in dSPE were studied and optimized in terms of sensitivity, and the optimum conditions were: mass of sorbent, 100 mg; donor phase volume, 75 mL; pH, 3; and sodium chloride concentration, 30% (w/v). After dSPE, the MNPs were eluted twice with 1.5 mL …
Selection of sampling adsorbents and optimisation and validation of a GC-MS/MS method for airborne pesticides
2017
ABSTRACTA methodology for the sampling and determination of airborne pesticides has been developed. The trapping efficiency of three adsorbents, namely XAD-2,XAD-4 and a sandwich sorbent (PUF-XAD2-PUF), was tested for 34 pesticides and the latter was selected because it presented the highest retention capacity without breakthrough. Pesticides were determined by gas chromatography coupled to an ion trap mass spectrometer in tandem. The method showed recoveries ranging from 70% to 120% with limits of quantification in the range of 16.1–322.6 pg m−3 when 155 m3 were sampled. This analytical strategy was applied to 10 indoor air samples collected in dwellings from the Valencian Region. Six pest…
Analytical characterization of diterpenoid resins present in pictorial varnishes using pyrolysis–gas chromatography–mass spectrometry with on line tr…
2005
Abstract A procedure based on the technique of the pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS) has been applied, in this work, in order to determine the composition of diterpenoid resin employed in art works. The method is based on the on line derivatization of these resins using hexamethyldisilazane (HMDS). Results obtained were compared with those previously reported in literature from Venice turpentine, Strasbourg turpentine, colophony, sandarac and Manila copal using this same method and with those others from in situ thermally assisted hydrolysis and methylation with tetramethylammonium hydroxide (TMAH). Canada balsam, copper resinate and Copaiba balsam have been also ana…
Development of a versatile, easy and rapid atmospheric monitor for benzene, toluene, ethylbenzene and xylenes determination in air
2009
Abstract A new procedure for the passive sampling in air of benzene, toluene, ethylbenzene and xylene isomers (BTEX) is proposed. A low-density polyethylene layflat tube filled with a mixture of solid phases provided a high versatility tool for the sampling of volatile compounds from air. Several solid phases were assayed in order to increase the BTEX absorption in the sampler and a mixture of florisil and activated carbon provided the best results. Direct head-space-gas chromatography–mass spectrometry (HS-GC–MS) measurement of the whole deployed sampler was employed for a fast determination of BTEX. Absorption isotherms were used to develop simple mathematical models for the estimation of…
Comparison of the volatile oils ofHypericum scabrum L. andHypericum perforatum L. from Turkey
1997
The composition of the volatile oils obtained from the aerial parts of Hypericum scabrum L. and H. perforatum L. was analysed by GC and GC‐MS. While the oil of H. scabrum L. contained a-pinene (71.6%), b-caryophyllene (4.8%), myrcene (3.8%), cadalene (3.4%) and b-pinene (2.9%), the oil of H. perforatum L. contained a-pinene (61.7%), 3-carene (7.5%), b-caryophyllene (5.5%), myrcene (3.6%), cadalene (3.2%) and other components. Twenty-nine and 27 terpenoid compounds have been identified in the volatile oils of H. scabrum L. and H. perforatum L., respectively. #1997 by John Wiley & Sons, Ltd.