Search results for "gas chromatography."
showing 10 items of 725 documents
Analysis of Essential Oils from Scutellaria orientalis ssp. alpina and S. utriculata by GC and GC-MS
2011
The chemical composition of the essential oils obtained from aerial parts of Scutellaria orientalis L. ssp. alpina (Boiss.) O. Schwarz and S. utriculata Labill. growing wild in Lebanon, were analyzed by GC and GC-MS. In S. orientalis ssp. alpina, strongly characterized by sesquiterpenes (41.2%) and particularly sesquiterpene hydrocarbons (31.7%), hexahydrofarnesylacetone (11.7%) was recognized as the main constituent, together with hexadecanoic acid (7.6%), caryophyllene (7.4%), caryophyllene oxide (6.8%), 4-vinylguaiacol (5.4%) and germacrene D (5.4%). S. utriculata oil was instead constituted above all by monoterpenes (42.2%), particularly oxygen containing monoterpenes (39.9%), and in t…
GC and GC/MS analysis of the essential oil of Salvia hierosolymitana boiss. Growing wild in Lebanon
2007
The essential oil of the aerial parts of Salvia hierosolymitana Boiss. (Lamiaceae), growing wild in Lebanon, was obtained by hydrodistillation and analysed by GC and GC-MS. Ninety-two compounds, representing 92.7% of the oil, were identified. The major components were hexadecanoic acid (15.5%), phytol (5.4%), hexahydrofarnesyl acetone (4.6%), (Z,Z)-9,12-octadecadienoic acid (4.5%) and 4-vinylguaiacol (4.4%).
Chemical composition of the essential oils of Centaurea formanekii and C. orphanidea ssp. thessala, growing wild in Greece.
2012
The volatile constituents of the aerial parts of Centaurea formanekii Halacsy and the aerial parts, capitula and roots of C. orphanidea Heldr. & Sart. ex Boiss. ssp. thessala (Hausskn.) Dostál from Greece were extracted by hydrodistillation and analyzed. The main components in C. formanekii were hexadecanoic acid (13.6%), δ-elemene (9.1%), and spathulenol (6.9%). The main components in C. orphanidea ssp. thessala were γ-elemene (26.1%) and caryophyllene oxide (13.2%) in the aerial parts, hexadecanoic acid (33.5%) and heptacosane (6.3%) in the capitula, and hexadecanoic acid methyl ester (22.0%) and α-chamigrene (14.0%) in the roots. The chemotaxonomic significance with respect to other…
Chemical Composition of the Essential Oil of Zingiber Zerumbet Var. Darcyi
2012
The chemical composition of essential oil obtained by hydrodistillation method from the rhizomes of Z. zerumbet var. darcyi was determined by GC and GC-MS. Thirty-three compounds, accounting for 93.6% of the oil were identified including twenty compounds in minor (0.1-0.6%) and eight in trace (<0.05%) amounts. The main compounds were zerumbone (69.9%) α-humulene (12.9%), humulene epoxide II (2.5%), caryophyllene oxide (1.1%) and camphene (1.9%). In this analysis, it has been found that the variety could be used as an additional new source of natural zerumbone besides Zingiber zerumbet. This is a first report on the analysis of Z. zerumbet var. darcyi oil.
Analysis of Essential Oil from Teucrium maghrebinum Greuter et Burdet Growing Wild in Algeria
2009
The chemical composition of the essential oil obtained from aerial parts of Teucrium maghrebinum growing wild in Algeria was analyzed by GC and GC-MS. Among the 66 identified compounds, δ-cadinene (12.7%), germacrene D (11.4%), γ-cadinene (9.5%) and 4-vinyl guaiacol (4.0%) were the most abundant. The oil is strongly characterized by the presence of sesquiterpenes (61.5%), particularly hydrocarbon sesquiterpenes (49.6%).
Environmental and Product Contamination during the Preparation of Antineoplastic Drugs with Robotic Systems
2018
Abstract Background Robotic systems are designed to minimize the exposure to antineoplastic drugs during automated preparation. However, contamination cannot be completely excluded. The aim of the study was to evaluate the contamination with antineoplastic drugs on the working surfaces and on the outer surface of the ready-to-use products (infusion bags and syringes) during automated preparation with different versions of a robot and manual preparation. Methods Surface contamination with platinum (Pt) and 5-fluorouracil (5-FU) was measured by wipe sampling and quantified by voltammetry for Pt and GC-MS for 5-FU. Sampling was performed on pre-defined locations in the working areas before and…
Study of the influencing effect of pigments on the photoageing of terpenoid resins used as pictorial media
2006
Abstract Terpenoid resins have been mainly used as components of pictorial varnishes and binding media from ancient times. In such latest instances, the resin is mixed with pigments affecting its physical and chemical properties. A new procedure based on gas chromatography–mass spectrometry (GC/MS) has been applied, in this work, in combination with Fourier transform infrared spectroscopy (FTIR), with the aim of determining the changes undergone by di- and triterpenoid resins employed as components of binding media. The GC/MS method is based on the derivatisation of these resins using trimethylsilylimidazol. Characterization of the main components of the di- and triterpenoid fractions and t…
Measurement of trace impurities in ultra pure hydrogen and deuterium at the parts-per-billion level using gas chromatography
2018
Abstract A series of muon experiments at the Paul Scherrer Institute in Switzerland deploy ultra-pure hydrogen active targets. A new gas impurity analysis technique was developed, based on conventional gas chromatography, with the capability to measure part-per-billion (ppb) traces of nitrogen and oxygen in hydrogen and deuterium. Key ingredients are a cryogenic admixture accumulation, a directly connected sampling system and a dedicated calibration setup. The dependence of the measured concentration on the sample volume was investigated, confirming that all impurities from the sample gas are collected in the accumulation column and measured with the gas chromatograph. The system was calibr…
Identification of Volatile Compounds in Blackcurrant Berries: Differences Among Cultivars
2021
Berries of blackcurrant are known to produce a strong flavor. Some previous studies have reported that a given cultivar of blackcurrant can produce berries with a specific profile of volatile compounds. For the Burgundy region in France, the Noir de Bourgogne cultivar is especially important because it is the main ingredient of a liquor with a designation of origin. The aim of the present study was to characterize the volatile fractions of berries from 15 cultivars in order to explore the possibility of using different cultivars for liquor production. The plants were cultivated under the same conditions and harvested in the same year. The volatile fractions of the harvested berries were ana…
Chemical Composition Analysis, Antimicrobial Activity and Cytotoxicity Screening of Moss Extracts (Moss Phytochemistry)
2015
Mosses have been neglected as a study subject for a long time. Recent research shows that mosses contain remarkable and unique substances with high biological activity. The aim of this study, accordingly, was to analyze the composition of mosses and to screen their antimicrobial and anticancer activity. The total concentration of polyphenols and carbohydrates, the amount of dry residue and the radical scavenging activity were determined for a preliminary evaluation of the chemical composition of moss extracts. In order to analyze and identify the substances present in mosses, two types of extrahents (chloroform, ethanol) and the GC/MS and LC-TOF-MS methods were used. The antimicrobial activ…