The isotope ratio of monoterpene hydrocarbons in citrus essential oils of different origins was measured by ordinary high-resolution gas chromatography-mass spectrometry (HRGC-MS). The isotope ratio (Ir) was determined by the ratio of the isotope peak intensity (m/z 137) to the molecular mass peak intensity (m/z 136) of the monoterpene hydrocarbons. The accuracy of Ir was examined by measuring ...

the water-distilled essential oils, which were obtained from the fresh aerial parts of satureja hortensis were analyzed by means of gc and cc/ms instruments. the plant was collected during the flowering stage from foroomad mountains, semnan province, and heart of iran. twenty compounds were identified in the different samples analyzed, representing 100% of the total oil contents. in terms of ge...

The composition of the essential oil of the fruits, leaves and stems of Daucus glaber Forssk has been studied by GC/MS. It was found that, the essential oil of the fruits consists of monoterpene hydrocarbons (limonene and sylvestrene are the majors) and phenylpropanoids (elemicin is the major). Sylvestrene has never been reported before in the essential oil of any Daucus species. The study of t...

The effects of essential oils isolated from Douglas fir needles on sheep and deer rumen microbial activity were tested by use of an anaerobic manometric technique. Rumen microorganisms were obtained from a sheep which had been fed mainly on alfalfa hay and dried range grass. One deer used in this study had access to Douglas fir trees the year around, whereas the other deer had no access to Doug...

The essential oil composition of the aerial parts of Nepeta raphanorhiza is reported for the first time. Capillary GC-FID & GC-MS analysis of the essential oil led to the identification of 16 components accounting for 97.5% of the total oil. Sesquiterpene hydrocarbons dominated the oil composition accounting for 65.3 % followed by monoterpene hydrocarbons constituting 19.5 % of the total oil co...

The volatile composition of fruit from four Citrus varieties (Powell Navel orange, Clemenules mandarine, and Fortune mandarine and Chandler pummelo) covering four different species has been studied. Over one hundred compounds were profiled after HS-SPME-GC-MS analysis, including 27 esters, 23 aldehydes, 21 alcohols, 13 monoterpene hydrocarbons, 10 ketones, 5 sesquiterpene hydrocarbons, 4 monote...