Search results for "Gas Chromatography"

Detection of the synthetic drug 4-fluoroamphetamine (4-FA) in serum and urine.

2010

Abstract 4-Fluoroamphetamine (4-FA) was detected in the blood and urine of two individuals suspected for driving under the influence (DUI). The test for amphetamines in urine subjected to immunoassay screening using the CEDIA DAU assay proved positive. Further investigations revealed a 4-FA cross-reactivity of about 6% in the CEDIA amphetamine assay. 4-FA was qualitatively detected in a general unknown screening for drugs using GC/MS in full scan mode. No other drugs or fluorinated phenethylamines were detected. A validated GC/MS method was established in SIM mode for serum analysis of 4-FA with a limit of detection (LOD) of 1 ng/mL and a lower limit of quantification (LLOQ) of 5 ng/mL. Int…

Analytical methods to determine cocaine contamination of banknotes from around the world

2008

Abstract The presence of cocaine in a significant number of UK pounds (Xxxx), Euros (€) and North American banknotes ($) in general circulation requires appropriate tools to do determinations. This article discusses the-state-of-the-art in the analysis of cocaine on banknotes. We summarize the usual extraction methods of currency samples and compare them, especially with respect to avoiding sample damage. We critically discuss analytical methods, namely gas chromatography (GC) and liquid chromatography (LC), capillary electrophoresis (CE), immunoassay, thermal desorption tandem mass spectrometry (TD-MS2) and ion-mobility spectrometry (IMS). We also review cocaine levels on banknotes around …

Essential Oils as Natural Biocides in Conservation of Cultural Heritage

2020

Essential oils (EOs) have been known for a long time, and they are used in several fields such as medicine and aromatherapy, as well as in the food and pharmaceutical industries. In the last decade, EOs have also been applied to contrast the biodeterioration of cultural heritage, representing a powerful resource in green conservation strategies. In this study, an integrated approach based on microscopic observation, in vitro culture, and molecular investigation was preliminarily employed to identify biological systems colonizing wooden artworks. In order to contrast the biodeterioration processes induced by fungal colonization (Aspergillus flavus) or insect infestation (Anobium punctatum), …

Characterization of Biodiesel from Vegetable Oil Using Comprehensive Two-Dimensional Gas Chromatography

2013

Biodiesel from vegetable oils has been analyzed and its suitability for internal combustion engines has been assessed. The Standard biofuel’s characteristics have been investigated. Gas chromatography (GC) tests were carried out to characterize the fatty acid behavior. It was found that the mass percentage of saturated fatty acids did not change substantially with time, while unsaturated fatty acids increased with time for both B100 and B30. An increase in density for B100 and B30 with time was noted. Biodiesel density was within the standardization. The calorific values of biodiesel and its blend increased with time. Higher heating value for B100 increased from 41 to 43 MJ/kg while B30 inc…

Chemical composition of essential oil from Italian populations of Artemisia alba Turra (Asteraceae).

2012

The use of essential oils as chemotaxonomic markers could be useful for the classification of Artemisia species and to caracterize biodiversity in the different populations. An analysis of the chemical composition of four essential oils from Italian populations of Artemisia alba Turra (collected in Sicily, Marche and Abruzzo) was investigated. In this paper an in depth study of the significant differences observed in the composition of these oils is reported.

Determination of biogenic amines in meat by combined ion-exchange capillary gas chromatography

1984

Abstract A procedure is described for the determination of putrescine, cadaverine and histamine in meat. Crude perchloric acid extracts were pre-separated on a weakly acidic cation exchanger and the amines quantified by capillary gas chromatography. The diamines were analysed as trifluoroacetyl derivatives and histamine was converted into N α -trifluoroacetyl-N τ -ethoxycarbonylhistamine. The accuracy of the determination of diamines was examined by a precipitation pre-separation method and by mass fragmentometric quantification. The proposed procedure allows the sensitive, sufficiently precise and highly specific determination of putrescine and cadaverine in meat.

Analytical characterisation of the biodeterioration of diterpenoid labdanic varnishes used in pictorial techniques: Sandarac and Manila copal

2014

Abstract The deterioration produced by fungal and bacterial growth on the sandarac and Manila copal, diterpenoid varnishes traditionally used as art materials, was evaluated by gas chromatography–mass spectrometry (GC–MS), and pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). Test specimens, coated with a solidified thin layer of the studied varnishes, were inoculated and incubated with selected fungi and bacteria obtained from collections and oil paintings affected by biodeterioration, and analysed by the above mentioned techniques. Significant changes were detected, showing evidence of deterioration processes caused or favoured by some of the studied microorganisms.

Relationship between conformation and physicochemical properties of polypeptides. II. GPC as a tool for the detection of conformational transitions o…

1983

Organic residues in lake and drinking water from the lagoa de Juturnaíba (região dos lagos - RJ, Brazil)

1997

Various analytical methods for the determination of organic residues in water were applied to samples from the Lagoa de Juturnaíba in the Região dos Lagos, east of Rio de Janeiro. The concentrations of more than 60 pesticides and of different aminopolycarboxylic acids were determined using GC/MS detection, and a GC/MS screening procedure was applied to detect additional compounds. None of the investigated pesticide residues could be detected in the lake water at detection limits of less than 100 ng/L. EDTA was detected at a concentration level of 2 mg/L in the lake and in drinking water prepared from this lake. Traces of biphenyl were identified by GC/MS in the lake water, the source of whi…

Isolation and identification of intermediates from biodegradation of low chlorinated biphenyls (Delor-103).

2004

Abstract Microorganism Pseudomonas species P2 metabolizes polychlorinated biphenyls (PCBs) and biphenyl, producing the whole spectrum of intermediates, among them coloured intermediates, which are suitable for the monitoring of PCBs degradation by optical sensors. Knowledge of chemical structures and conditions of development of colour metabolites is necessary for application of optical analytical methods. The main goal of this work was the isolation and identification of intermediates from the biodegradation of the mixture of low chlorinated biphenyls (Delor-103), which is based on the solid phase extraction (SPE) of the whole mixture using LiChrolut EN cartridges, then silylation of the e…