the essential oils of the aerial parts of three different artemisia species (a.scoparia, a. diffusa, a. turanica ) growing wildly in the northeast of iran were analyzed by gc-ms. twenty-two, twenty-six, and thirteen components were identified in the essential oils of these plants, respectively. the major constituents of the oil ofa. scoparia were b-pinene (16.10%), carvacrol (13.81%), limonene ...

results glandular trichomes composed of capitates and peltate trichomes. the essential oil composition differs. viridiflora and neryl acetate were not identified in yellow glandular trichomes. conclusions it seems that there is no relation between anatomical characteristics of the plant leaves and its essential oil composition. background perovskia abrotanoides karel. is a medicinal plant used ...

The current study applied gas chromatography-mass spectrometry (GC–MS), liquid (LC-MS), and thermal desorption direct analysis in real-time mass (TD-DART-MS) methods to the of black pepper (Piper nigrum L.) samples from different countries. powder were analyzed directly by TD-DART-MS without any extraction, but for GC–MS LC-MS methods, a methanol extraction procedure was employed before analysi...

GC/MS/MS techniques to quantitate mixtures of acyclic stereoisomers are explored for a set of secondary n-alkyl phenyl ethers vicinally substituted with deuterium. Examination of a set of test compounds using a commercial quadrupole ion trap instrument (GC/QIT) reveals large differences between threo and erythro diastereomers when trapped molecular ions expel neutral alkene as a result of colli...

This overview evaluates the capabilities of mass spectrometry (MS) in combination with gas chromatography (GC) and liquid chromatography (LC) for the determination of a multitude of pesticides. The selection of pesticides for this assessment is based on the status of production, the existence of regulations on maximum residue levels in food, and the frequency of residue detection. GC-MS with el...

BACKGROUND Activation of the type I interferon (IFN) response program is described for several autoimmune diseases, including systemic lupus erythematosus (SLE), multiple sclerosis (MS), myositis (IIM) and rheumatoid arthritis (RA). While IFNα contributes to SLE pathology, IFNβ therapy is often beneficial in MS, implying different immunoregulatory roles for these IFNs. This study was aimed to i...

Muramic acid (Mur) is present in the cell wall of Eubacteria and serves as a chemical marker for the trace detection of bacteria and bacterial cell wall debris in complex matrices. There have been numerous studies using a variety of derivatives of Mur, particularly in combination with gas chromatography-tandem mass spectrometry (GC-MS-MS) where the detection limit has been steadily lowered. A s...

A simple and high-throughput screening method for the analysis of 136 pesticides in avocado ( Persea americana ) by LC-(+)-ESI-MS/MS and GC-MS/MS is presented. A modified QuEChERS sample preparation method was developed to improve the extraction recovery of highly lipophilic pesticides. Extracts from minced avocados after acetonitrile (MeCN) extraction were directly injected to LC-MS/MS, wherea...