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 ...

We report a modified micro-scale gas-chromatographic procedure for determining phenobarbital, primidone, and diphenylhydantoin in serum with use of a nitrogen/phosphorus detector. Serum, 20 mul, is extracted into chloroform, the solvent is evaporated, and the residue dissolved in dilute (32 mmol/liter) trimethylanillinium hydroxide, which yields the methyl-derivatives of the drugs upon on-colum...

We developed a reversed-phase chromatographic procedure for detecting benzodiazepines and other drugs in serum. A liquid-liquid extraction step with hexane/ethyl acetate isolates the drugs from serum; absolute recoveries are generally greater than 85%. Reconstituted extracts are chromatographed on a 4-microns (particle size) C18 column; 14 drugs and an internal standard (flunitrazepam) are sepa...

A method for isolating organic acids from acidified urine on an equivolume mixture of Porapak Q and Porapak T is described, and results are compared with extraction with ethyl acetate and ion exchange on DEAE-Sephadex. Average recoveries of 14C-labeled oxalic acid, lactic acid, succinic acid, alpha-ketoglutaric acid, citric acid, and cinnamic acid were equal to or better than those obtained wit...

This study describes optimization of headspace solid phase microextraction followed by gas chromatography equipped with a flame ionization detector for toluene at trace level in spiked urine. The parameters affecting the extraction and gas chromatographic determination of analytes were studied: extraction time and temperature; desorption time and temperature; addition of NaCl; and pH, volume an...

A bstract. This paper describes a new method for qualitative and quantitative assay of abscisic acid and other acidic plant hormones, such as indoleacetic acid and the gibberellins, by the gas-liquid chromatography of their trimethylsilyl derivatives. Interfering substances in plant extracts were largely removed by preliminary oolumn chromatography with carbon-celite and elution of the absoisic...

objective(s): dispersive liquid-liquid microextraction coupled with gas chromatography (gc)-flame ionization detector was developed for the determination of valproic acid (vpa) in human plasma. materials and methods: using a syringe, a mixture of suitable extraction solvent (40 µl chloroform) and disperser (1 ml acetone) was quickly added to 10 ml of diluted plasma sample containing vpa (ph, 1.0...

valproic acid (vpa) is one of the mostly used antiepileptic drugs that may have some side effects so, it is highly recommended to evaluate its serum concentrations. the aim of this study was to develop a simple, fast and economic method using gas-chromatography equipped with flame ionization detector (gc/fid) and vpa analysis. to do this, 200 µl of serum was mixed with an aliquot of caproic aci...

background and aims: walnuts are good sources of polyunsaturated fatty acids (pufa) and polyphenols which have beneficial effects such as proper growth, decreasing coronary heart disease, prevention of several kinds of cancer, anti-inflammatory and anti-mutagenic activities. in this study, the fatty acid content and antiradical activity of different walnut (juglans regia l.) genotypes grown in ...

the aim of this study was to investigate the removal of toluene from air through nano-graphene modified by ionic liquid (ng-il). the batch adsorption experiments in glass bottle of gas chromatography equipped with flame ionization detector (gc-fid) were used. graphene ultrahigh-quality synthesized by substrate-free gas-phase method in a single step and graphene sheets were deposited with ionic-...