Oleic acid is a common pharmaceutical excipient that has been widely used in various dosage forms. Gas chromatography (GC) has often been used as the quantitation method for fatty acids normally requiring a derivatization step. The aim of this study was to develop a simple, robust, and derivatization-free GC method that is suitable for routine analysis of all the major components in oleic acid ...

A three-step development, optimization and validation strategy is described for gas chromatography (GC) fingerprints of Brazilian commercial diesel fuel. A suitable GC-flame ionization detection (FID) system was selected to assay a complex matrix such as diesel. The next step was to improve acceptable chromatographic resolution with reduced analysis time, which is recommended for routine applic...

The volatile compounds from Maclura pomifera (Osage orange fruit) peel have been studied by GC-FID and GC–MS. Volatiles fraction proportion was estimated to 60 mg/kg. Identified compounds consist on aliphatics (52.6%), monoterpenes along with sesquiterpenes (27.3%), phenylpropane derivatives along with related compounds (10.0%) and other compounds (10.6%). Among the 60 identified compounds, 1-h...

This study investigated the chemical composition and in-vitro cytotoxic activities of the essential oil isolated from the leaf of Beilschmiedia erythrophloia. The essential oil was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. Fifty-five compounds were identified, representing 100% of the oil. The main components identified were beta-cary...

The chemical composition of the essential oils from leaves and wood of Ocotea brenesii Standl. growing wild in Costa Rica was determined by capillary GC/FID and GC/MS. From the leaves, 64 compounds were identified, corresponding to 85.9% of the oil, and from the wood 57 compounds were identified corresponding to 69.0% of the oil. The major constituents identified in the leaf oil were alpha-copa...

The composition of supercritical CO2 extracts and essential oils obtained by hydrodistillation of Bupleurum fruticosum L., growing spontaneously in Italy and Portugal, and its antifungal activity is reported. The collected extracts were analyzed by GC-FID and GC-MS methods. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal...

Different solvent extracts of a red algae, Hypnea flagelliformis, and two brown algae, Cystoseira myrica and Sargassum boveanum, which were collected from the Persian Gulf coast were subjected to different bioassays, including: 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, antibacterial and antifungal activity by thin layer chromatography (TLC)-bioautography, agar disc dif...

This work describe products of reactions between four alpha-dicarbonyl compounds (diacetyl, pentan-2,3-dione, glyoxal, and methylglyoxal) or two alpha-hydroxy ketones, (acetoine and acetol) and amino acids present in wines. The results shows the formation of odorous products or strong-smelling additives resulting from the Maillard and Strecker reaction in a primarily aqueous medium, at low temp...

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...