We investigated whether methane, ethylene and ethane gas can be detected in gas emanating from human skin, which is called skin gas. Skin gas was collected with a homemade stainless-steel trap system, which was cooled with liquid nitrogen, and analyzed with a gas chromatograph fitted with a flame ionization detector (FID). Skin-gas samples were obtained by covering a hand for 30 min with a poly...

The use of pesticides provides benefits such as growing food products necessary for life, sustainability production efficiency and prevention diseases caused by pests. However, these can turn into negative effects humans other living organisms with the in inappropriate doses application methods. In this study, it was aimed to determine resmethrin, which belongs insecticide class, gas chromatogr...

the aim of this study was evaluation of phytochemical components, antioxidant activity, and antibacterial effects of basil (ocimum basilicum l.) essential oil (beo) in vitro. the lipid oxidation of the meat and antibacterial effects of beo were also evaluated in beef burger product. in this empirical study, essential oil of the basil was isolated by hydrodistillation. then, beo was analyzed by ...

Two detection systems for gas-liquid chromatography were compared for the identification of metabolic end products (short-chain organic acids) from anaerobic bacteria. Argon and flame ionization detectors were connected in series with inert argon as the carrier gas for analysis of 35 stock strains and 148 clinical isolates. There was an excellent correlation between the argon and flame ionizati...

During the MINOS campaign in August 2001 comprehensive two-dimensional gas chromatography (GC×GC) was applied to the in situ measurements of atmospheric volatile organic compounds (VOCs) at the Finokalia ground station, Crete. The measurement system employs a thermal desorption unit for on-line sampling and injection, and a GC×GC separation system equipped with a flame ionization detector (FID)...

Multiple field studies have suggested chemistry within a forest canopy is poorly understood due to inadequate detection and quantification of reactive biogenic emissions, such as terpenes. To measure emission rates of terpenes at Blodgett Forest, a coniferous forest in the Sierra Nevada mountains of California, we placed enclosures over branches of the dominant species at the site – Ponderosa p...

The Smith-Lemli-Opitz syndrome (SLOS), is an autosomal recessive disorder caused by a 7-dehydrocholesterol reductase deficiency, which is characterized by abnormally elevated amniotic fluid 7-DHC (7-dehydrocholesterol) concentrations. A GC/FID (gas-chromatography with a flame ionization detector) and GC/MS (gas-chromatography with a mass detector) method was optimized for the detection of chole...

Background: Nanotechnology is a new approach that has been lionized in recent years. One of its applications is its consumption as an absorbent. In this study, the single-wall carbon nanotubes (SWCNTs) were used as an absorbent for sampling benzene in the air. Materials and Methods: For this study, SWCNTs manufactured by Iran and SKC’s activated charcoal were used for sampling benzene vapors....

Vacuum-outlet operation of short fused-silica open tubular columns for gas chromatography provides benefits to analysis speed by increasing the optimum velocity while minimizing the loss in resolution. Vacuum-outlet operation of a column with a gas chromatographic detector necessitates that the detector also be under vacuum. Simple modifications were made to a gas chromatograph]flame Ž . ioniza...

in this study, both the presence and concentration of some unsaturated compounds in hexane extracts of different parts of anthemis talyschensis showing absorption at wavelength 280-450 nm were surveyed, with the view of possibly using extracts of this plant in new formulations of sunscreen creams. the hexane extracts of flower, leaf and stem of a. talyschensis , collected from northwest iran, w...