Search results for "Flame ionization detector"
showing 4 items of 24 documents
Aroma characterization of freshly-distilled French brandies; their specificity and variability within a limited geographic area
2016
Freshly-distilled French wine brandies were evaluated by gas chromatography-olfactometry (GC-O). Six brandy samples were studied, coming from two growth areas, both belonging to the same limited geographic zone, which is a homogeneous vineyard area. The GC-O methodology, using detection frequency analysis, revealed 88 olfactive areas (OAs) for which the detection frequency was ≥ 25%. OAs were then identified using gas chromatography-mass spectrometry in electron and chemical ionization modes and semi-quantified by internal normalization using gas-chromatography with flame ionization detection. Co-eluting species were separated by multidimensional gas chromatography-mass spectrometry/olfacto…
Pyrolysis-gas chromatography-mass spectrometry of cured phenolic resins.
2003
A previously described pyrolysis device with a movable reaction zone was used in the present work for thermal degradation of cured novolac and resol resins. After the pyrolysis the usual major components were identified, as well as relatively low-volatile aromatic compounds which were revealed after their separation in a capillary chromatographic column. Among the latter components, for both types of cured resins, xanthene and its methyl derivatives were found. The isomers of bis(hydroxyphenyl)methane were found in considerable quantities only in the case of partially cured novolac resins which contained any linear sequences in their structure.
Analytical study of proteinaceous binding media in works of art by gas chromatography using alkyl chloroformates as derivatising agents.
2001
In this work, we present the results obtained in an analytical study of the different types of proteinaceous binding media most commonly used in paintings, using GC-FID as the technique of analysis and GC-MS as a confirmatory technique. The application of this methodology requires prior hydrolysis of the proteins in the binding media to obtain free amino acids and then volatile derivatives, in this case by reaction with chloroformates due to advantages of speed, safety and the aqueous medium in which the reaction occurs. The method proposed for the proteinaceous binding media study is to calculate the proportions of the different amino acids with respect to alanine. This method provided goo…
Analysis of odour and taste problems in high-density polyethene
1998
Abstract The compounds that cause off-flavours in plastics, have been recognized mainly as carbonyl compounds (aldehydes, ketones and esters). They occur in low concentrations, and due to their low-threshold odour concentrations, their typical odours were identified. Most of these off-flavour compounds are volatile. Chemical analysis of smelling compounds requires a very sensitive method with a high-resolution capability. The analysis of volatile organic compounds (VOCs) in high density polyethene (HD-PE) granules and waters in which the granules have been shaken for 4 h, were carried out by gas chromatography–mass spectrometry–sniffing system (GC–MS–SNIFF) and by gas chromatography–fourier…