In recent years, comprehensive two-dimensional gas chromatography (GC x GC) has attained increasing attention for its outstanding separation potential and capability to solve demanding analytical tasks. Trace level analysis of pesticides residues in complex food matrices represents such a demanding task. For some commodities, such as baby food, the requirements on method detection limits are ve...

Pesticide residue analysis in medicinal herbs is a challenging task because of the matrix effect and its influence on quantitative despite continuous development several new analytical methods instrumentations. In this study, modified QuEChERS method was developed for indoxacarb by using conventional instrument, gas chromatography micro-electron-capture-detector (GC–μECD), comparing it with chr...

The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextr...

background many members of the genus satureja have aromatic and medicinal characteristics. objectives results thymol (34.5%), γ-terpinene (18.2%) and ρ-cymene (10.5%) were the main components of the essential oil. the toxicological study on 5637 and kyse cell lines showed ic50 values of 156 μg/ml. the essential oil exhibited considerable antimicrobial activity on tested bacteria and fungi. mate...

Hypericum Perforatum L., commonly known as St. John’s wort, is one of the best-known medicinal herbs. wort infused oils are mostly used externally, but can be taken orally for stomach ulcers, a food supplement. Therefore, it important to develop methods that allow rapid and reliable determination β-caryophyllene, which main active components wort. In this work, two gas chromatographic technique...

in this study 50 samples of ecstasy tablets seized in iran during the period of 2007 through 2008 were examined and their physical characteristics (appearance, marking, scored/not scored, color, weight, diameter, thickness) were determined. in order to determine the chemical characteristics of these tablets, color tests (marquis test, simon’s test, chen’s test and gallic acid test), thin layer ...

A robust and complete workflow for metabolic profiling and data mining was described in detail. Three independent and complementary analytical techniques for metabolic profiling were applied: hydrophilic interaction chromatography (HILIC–LC– ESI–MS), reversed-phase liquid chromatography (RP–LC–ESI–MS), and gas chromatography (GC–TOF–MS) all coupled to mass spectrometry (MS). Unsupervised method...

high-performance liquid chromatography with UV detection (HPLC–UV), liquid chromatography coupled with tandem mass spectrometry (LC–MS–MS), and gas chromatography with mass spectrometry (GC–MS) for the characterization and C=C bond localization on the long chain base of sphingolipids in yeast extracts in order to identify the plant sphingolipid desaturases activity. Samples of wild type control...

BACKGROUND Derangements of one-carbon metabolism have been related to the development of chronic diseases. Metabolic profiling as part of epidemiological studies in this area should include intermediates involved in the transfer of one-carbon units, cofactors for the relevant enzymes and markers of inflammation, kidney function and smoking. METHODS We established five platforms that measured ...

In this research, CaO (calcium oxide) nanoparticles were synthesized by Co-Precipitation method in the absence and presence of Polyvinylpyrrolidone (PVP) via using calcium (II) nitrate. The Polyvinylpyrrolidone (PVP) was used as a capping agent to control the agglomeration of the nanoparticles. The synthesized samples were characterized via SEM, XRD and FTIR techniques. The average sizes of nan...