Search results for "gas chromatography."

The BIOSAFEPAPER project for in vitro toxicity assessments: preparation, detailed chemical characterisation and testing of extracts from paper and bo…

2008

International audience; Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-foo…

Gas-liquid chromatography as a tool for evaluation of lipophilicity of selected esters of aromatic and aliphatic acids

1986

Abstract The use of gas-liquid chromatographic retention values for the determination of lipophilicity was studied for series of esters of aromatic and aliphatic acids and for series of aliphatic alcohols. The regression relationships between the logarithms of the partition coefficients and the retention characteristics measured on two capillary columns, SE-30 and OV-351, differing markedly in polarity, were evaluated. It may be deduced that, for the structurally similar compounds, the stationary phases used simulate the reference partitioning system octanol-water.

Retention of Carvacrol and Ethyl Acetate in Aqueous Gels of Potato Starch and Konjac Glucomannan

2014

The partition coefficients of two volatile compounds in dispersions containing potato starch (PS) and/or konjac glucomannan (KGM) have been determined by the phase ratio variation method using equilibrium headspace analysis by gas chromatography. The influence of the moment when volatile compounds were added and the effect of the polysaccharide dispersions were investigated. For ethyl acetate, retention by KGM was based on viscosity effect. Retention of carvacrol was important when amylose was accessible. The addition of KGM to PS suspensions decreased the retention governed by interactions with starch.

SPME of 52 pesticides and polychlorinated biphenyls: Extraction efficiencies of the SPME coatings poly(dimethylsiloxane), polyacrylate, poly(dimethyl…

2001

Fiber/water partition coefficients (Kfw) of 52 pesticides, including triazines, organophosphorus pesticides, organochlorine pesticides, and polychlorinated biphenyls (PCBs) were experimentally calculated for the five polymeric coatings poly(dimethylsiloxane) (PDMS), polyacrylate (PA), poly(dimethylsiloxane)-Divinylbenzene (PDMS-DVB), Carboxen-poly(dimethylsiloxane) (CAR-PDMS), and Carbowax-divinylbenzene (CW-DVB) commercially available for solid-phase microextraction coupled to gas chromatography. The equilibrium-time profiles for the five coatings were previously studied in order to establish the time needed for equilibrium. To calculate Kfw the amount of analyte extracted at equilibrium w…

Composition of the essenthial oil of Petagnaea gussonei (Sprengel) Rauschert, a relict species from Sicily (Southern Italy).

2008

The essential oil from leaves, stems and roots of Petagnaea gussonei (Sprengel) Rauschert ( = Petagnia saniculifolia Guss.), endemic to the Nebrodi Mountains (Sicily, Italy), has been analysed by the gas chromatography–mass spectrometry (GC–MS) system on two fused-silica capillary columns of different polarities. A total of 94 components were identified. Quantitative and qualitative differences were found among the analysed parts. The principal compounds from the leaves oil were found to be (w/w%) germacrene D (19.9%), γ-muurolene (7.96%) and caryophyllene oxide (6.85%), while in the oil from stems hexadecanoic acid (23.40%), germacrene D (18.50%) and (Z,Z)-9,12-octadecadienoic acid (13.20%…

Novel Source of Ubiquitous Phthalates as Analytical Contaminant

1981

Volatile Components of Centaurea Bracteata and C. Pannonica subsp. Pannonica growing wild in Croatia

2010

This paper reports on the volatile components of oils from the aerial parts (CBA) and roots (CBR) of Centaurea bracteata Scop. and aerial parts of C. pannonica (Heuffel) Simonkai subsp. pannonica (CPA), two Asteraceae growing wild in Croatia. The volatile components, obtained by hydrodistillation, were determined by GC-MS analysis. The yields (w/w) of the dried oils were 0.10% (CBA), 0.22% (CBR) and 0.09% (CPA), respectively. A total of 91 compounds were identified accounting for 91.1%, 93.3% and 87.9% of the total oil for CBA, CBR and CPA, respectively. All the samples were characterized mainly by hydrocarbons (7.1-34.1%), fatty acids (9.7-45.9%), and oxygenated sesquiterpenes (15.2-16.6%…

Determination of Aldicarb, Aldicarb Sulfoxide, and Aldicarb Sulfone in Oranges by Simple Gas–Liquid Chromatography with Nitrogen–Phosphorus Detection

1994

Abstract A reversed-phase liquid chromatographic method, using an acetonitrile–water gradient mobile phase, and a gas-liquid chromatographic method with nitrogen–phosphorus and flame photometric detection were compared for simultaneous and separate determinations of trace quantities of aldicarb and its metabolites aldicarb sulfone and aldicarb sulfoxide. One hundred gram samples of fortified oranges were extracted with water–acetone, water-acetonitrile, or water–methanol, and the extracts were partitioned with methylene chloride. Partitioning with other organic solvents such as chloroform, ethyl acetate, or methyl isobutyl ketone was also investigated. When performed under optimal condition…

Gas chromatography/mass spectrometry of catechol estrogens

1992

Abstract Catecholestrogens (CCEs), namely 2- or 4-hydroxyestradiol and hydroxyestrone, are highly polar, reactive, and extremely labile estrogen metabolites in many experimental conditions. For these reasons, indirect assay methods mainly have been used. Some experimental evidence suggests that CCEs are synthesized and biologically active mostly in target cells. At this level, unfortunately, the indirect assays cannot be used. We present a method of gas Chromatographic/mass spectral (GC/MS) analysis for the identification of individual CCEs; the major fragmentation ions of authentic estrogen standards as trimethylsilylether derivatives, and the MS patterns of the major CCEs, namely, 2-hydro…

Compositions of the Volatile Oils of Citrus Macroptera and C. Maxima

2012

The essential oils obtained by hydrodistillation from the fresh peels of Citrus macroptera Montr. and C maxima(Burm.) Merr. were analyzed by GC and GC/MS. The yields of oil ranged from 0.53% in C macroptera to 0.13% in C maxima cultivar (white). Forty-seven compounds were identified in the oils with limonene (55.3-80.0%), dodecyl acrylate (2.2-8.0%), geranial (0.4-3.5%), trans-linalool oxide (1.0-2.8%), α-terpineol (0.7-2.3%), linalool (0.7-1.5%) and cis- linalool oxide (0.5-1.4%) identified as major compounds. The oil of C. macroptera contained limonene (55.3%), β-caryophyllene (4.7%) and geranial (3.5%) as main compounds. Similarly, oils from two C maxima(pink and white) cultivars were r…