A new single-drop microextraction approach is proposed for the extraction of compounds with a wide range of volatilities from tap water samples with separation/detection by gas chromatographymass spectrometry. This new microextraction mode is called direct immersion-headspace-single drop microextraction (DI-HS-SDME). Trihalomethanes (THMs), hydrocarbons with low molecular weight (benzene, ethyl...

in this work, zncao2 (zinc oxide-calcium oxide) nanocomposite were synthesized at different temperatures (500-700°c) by sol-gel method based on polymeric network of polyvinyl alcohol (pva). the synthesized samples were characterized by sem/edax, ft-ir and xrd techniques. it was found that synthesized nanocomposites have 1.62, 2.05 and 13.91%wt of cao, respectively. the obtained results show tha...

This study was undertaken to elucidate the dominant endogenous gibberellins (GA) and the changes in their levels in germinating barley during malting. Also, a method for determining gibberellins in barley and malt by combined gas chromatography-mass spectrometry (GC-MS) was developed. Endogenous gibberellins in germinating Fuji Nijo I I and Betzes barley were sequentially extracted with ethanol...

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...

A sensitive and simple Gas Chromatographic-Mass Spectrometric method was developed and validated for the determination of captopril in human plasma. Thiosalicylic acid was used as an internal standard, and plasma extraction was performed by solid phase extraction. The limit of quantification was 0.5 ng/mL with signal to noise ratio greater than 5. The calibration curve was linear from 1 to 160 ...

Introduction: The members of the genus Tanacetum are important medicinal plants. This study investigated the chemical composition and antibacterial activity of Tanacetum lingulatum and Tanacetum polycephalum essential oils on human infectious bacteria. Methods: The aerial part of two plants were collected from Urmia Province, Iran. The essential oils were extracted using a Clevenger device. The...

OBJECTIVE The alteration of steroid hormonal status in premenopausal breast disease (benign and malignant) were investigated by comparing the urinary profile of androgens and corticoids. METHODS The urinary concentrations of 25 androgens and corticoids were quantitatively determined by a gas chromatographymass spectrometry system in patients with benign breast disease (35 cases, 20-54 years),...

In the present study, the safety and toxicity of Dendrophthoe pentandra (DP) extracted using ethyl acetate were investigated. DP ethyl acetate (DPEA) extract was screened for its phytochemical constituents using standard procedure and active compounds present in DPEA extract were determined using gas chromatographymass spectrometry (GC-MS), the toxicity of DPEA extract was investigated using br...

During the Medieval Climate Anomaly (MCA), Western North America experienced episodes of intense aridity that persisted for multiple decades or longer. These megadroughts are well documented in many proxy records, but the causal mechanisms are poorly understood. General circulation models (GCMs) simulate megadroughts, but do not reproduce the temporal clustering of events during the MCA, sugges...