simple, cheap and green protocol for effective conversion of alcohols to corresponding carbonyl compounds in the presence of h14[nap5w30o110] and ammonium nitrate is reported. the products were characterized by ft-ir and comparison of their physical properties with those reported in the literatures. the progress of the reaction was monitored by thin layer chromatography (tlc) technique. the ali...

A simplified method for following the urinary excretion of estriol, pregnanediol, and pregnanoloneduring the course of pregnancy is presented. The procedure has been used successfully in a large hospital laboratory. An important advantage is that the estrogen and progesterone metabolites are measured simultaneously, and separate extraction and gas-liquid chromatographyis not required. The urine...

Migration of chemicals from plastic containers into drinks and liquids containing them, is supposed to be a hazardous phenomenon and results in many health problems. Sample preparation is of great importance due to trace amounts analysis of these compounds. In this research, dispersive liquid–liquid microextraction is applied for the extraction and preconcentration of the migrated compounds pri...

The essential oil in leaves of Polygonum minus Huds., a local aromatic plant, were identified by a pipeline of gas chromatography (GC) techniques coupled with mass-spectrometry (MS), flame ionization detector (FID) and two dimensional gas chromatography time of flight mass spectrometry (GC x GC-TOF MS). A total of 48 compounds with a good match and high probability values were identified using ...

In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for first time as a natural, ecological, and sustainable corrosion inhibitor acid cleaning carbon steel. The extracted by hydrodistillation using Clevenger-type apparatus, analyzed gas chromatography–flame–ionization detection (GC–FID) chromatography–mass spectrometry (GC–MS). most abundant components in were ?-pi...

in the present study the volatile organic compounds of e. azerbaijanica rech.f. were identified. phytochemical assessment of meoh extract of aerial parts of this plant was also performed and its free radical scavenging properties was evaluated. the essential oil of the air-dried aerial parts was obtained by hydro-distillation using a clevenger type apparatus. the oil was then analyzed by gas ch...

A new method for online measurement of volatile fatty acids (VFA) in anerobic digesters has been developed based on headspace gas chromatography (HSGC). The method applies ex situ VFA stripping with variable headspace volume and gas analysis by gas chromatography-flame ionization detection (GC-FID). In each extraction, digester sample was acidified with H(3)PO(4) and NaHSO(4), then heated to st...

A simple andefficient hollow fiber-based method,viz magnetic solvent bar liquid-phasemicroextraction (MSB-LPME) combined with gas chromatography-flame ionization detection (GCFID)has been successfully developed for the trace determination of mononitrotoluenes (MNTs) innatural water samples. The analytes were extracted from sample solution to the organic solventimmobilize...

An air–assisted liquid–liquid microextraction method for the extraction and preconcentration of trace amounts of some synthetic phenolic antioxidants in biological fluids followed by their determination by gas chromatography–flame ionization detection has been reported. In this method the target analytes are extracted into a few microliters of carbon tetrachloride (extraction solvent) from an a...

In the present work, a stainless steel wire was etched by hydrochloric acid during a chemical etching process. The obtained black layer on the surface of the fiber was used as sorbent for extraction of trace amount of phthalates in the aqueous samples by solid phase microextraction. New fiber efficiency was investigated using a home-made solid-phase microextraction (SPME) device and gas chr...