physical and chemical properties of  crude oil, including viscosity and api gravity, are commonly inherited  from the  early organic matter, environmental conditions in which they were deposited and depth of burial of the source beds. api gravity increases in deeper burial due to higher thermal maturation of organic matter in the source rocks and consequently, generation of lighter saturated hy...

The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at the Woods Hole Oceanographic Institution has developed an Accelerator Mass Spectrometry (AMS) system designed specifically for the analysis of C in a continuously flowing stream of carrier gas. A key part of the system is a gas-accepting microwave ion source. Recently, substantial progress has been made in the develo...

gas chromatography (gc) and gas chromatography mass spectrometry (gc-ms) were employed to determine the chemical composition of essential oil obtained from dry fruits of carum copticum. thymol (36.7%), -terpinene (36.5%) and -cymene (21.1%) were found to be the major constituents of the oil. the anti-bacterial activities of the oil were mainly investigated against food poisoning bacteria (sal...

a combined gas chromatography–mass spectrometry (gc–ms) with headspace solid-phase microextraction (hs-spme) method has been employed for the analysis of the flavor volatiles of some iranian rice cultivars (domsiah, deylamani, hashemi, shirodi and tarom). the samples were grown in different cities of mazandaran province. the sampling procedure and chromatographic conditions were same for all sa...

background: a new microextraction method named dispersive liquid-liquid microextraction (dllme) for determination of chloroform in pool water and blood of swimmers after swimming is described. methods: this method was performed based on coupling dispersive liquid-liquid microextraction (dllme) with gas chromatog­raphy-mass spectrometry (gc-ms). methanol and trichloroethylenes were used as the d...

objective: scutellaria luteo-caerulea bornm. & snit. is one of the species of genus scutellaria, within the family of the lamiaceae, that is used for immune system stimulation and antibacterial effects in traditional medicine in iran. the aims of this study were to analyze essential oils and mineral element contents of leaves of  s. luteo-caerulea in flowering stage of development. materials an...

background adulterated herbal weight loss products with containing undeclared synthetic drugs are common and responsible for many serious health damages. objectives the purpose of the study was to determine five synthetic adulterants in eight common herbal weight loss supplements, which are currently sold in iran markets, to verify their presence in supplements, without mentioning on the labels...