In this research the lipid fraction of two strains of Streptococcus thermophilus was studied. Lipids were extracted by applying Folch method and fractioned by thin layer chromatography (TLC). Fatty acid composition was determined both before TLC, on the total fat extracted, and after TLC on diacylglycerol and apolar fractions. Gas chromatographic analysis was performed by using both flame ioniz...

Background Biodiesel, an alternative energy source, has been attracting increasing worldwide interest in recent decades. It is obtained by base-catalyzed transesterification, resulting in a final mixture consisting of mono-alkyl esters and other by-products (e.g. glycerol, alcohol, free fatty acids). This composition provides a level of operational quality control that enables biodiesel to be m...

Six cultivars (Franquette, Marbot, Mayette, Mellanaise, Lara, and Parisienne) of walnuts (Juglans regia L.) were collected during the 2001 crop, from Bragança, Portugal. Chemical composition, including moisture, total oil content, crude protein, ash, carbohydrates, and nutritional value, was evaluated. Fat was the predominant component, ranging from 62.3 to 66.5%. Total oil was extracted and an...

Menthol is widely used as a fragrance and flavor in the food and cosmetic industries. It is also used in the medical and pharmaceutical fields for its various biological effects. Gas chromatography (GC) is considered to be a sensitive method for the analysis of menthol. GC chromatographic separation was developed using capillary column (VF-624) and a flame ionization detector (FID). The method ...

The main effects of six experimental factors on the efficiency of HS (headspace) extraction in headspace gas chromatography--flame ionization detector (HS-GC-FID) determination of twenty organic solvents routinely used in production of pharmaceuticals were obtained on the basis of the results of experiments carried out according to the Plackett-Burman factorial design. The effects were used as ...

ABSTRACT Oil blending is often used to enhance the properties of vegetable oils. The admixture of a more thermally stable oil makes the resulting blend more suitable for use in frying. A new method of quality assessment of vegetable oils used in frying is presented in this paper. In this method, ultra-fast gas chromatography coupled with flame ionization detector and chemometrics is employed. P...

The present work aimed to evaluate whether it is possible to use oral fluid to monitor alcohol in drivers. In a control experiment the subjects ingested beer with an alcoholic percentage of 4.7%, in an amount that furnished 0.5 g ethanol per kg of body weight. Volunteer's urine, oral fluid, and breath were collected at 10, 30, 60, and 90 min after alcohol intake. Urine and oral fluid were analy...

the our main goal of the present research is evaluating the performance of mno2 nanoparticles-agx zeolite composite as a novel adsorbent catalyst for the decontamination reactions of two most known sulfur mustard simulants; 2-chloroethyl phenyl sulfide (2-ceps), 2-chloroethyl ethyl sulfide (2-cees) at room temperature and monitoring by gas chromatography flame ionization detector (gc-fid) and g...

different solvent extracts of a red algae, hypnea flagelliformis,and two brown algae, cystoseira myrica and sargassum boveanum, 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 diffusion (add) ...

A new NMF algorithm has been proposed for the deconvolution of overlapping chromatograms of chemical mixture. Most of the NMF algorithms used so far for chromatogram separation do not converge to a stable limit point. To get same results for all the runs, instead of random initialization, three different initialization methods have been used namely, ALS-NMF (robust initialization), NNDSVD based...