نتایج جستجو برای: headspace solid

تعداد نتایج: 191043  

Journal: :journal of food biosciences and technology 0

abstract: a combined gas chromatography-mass spectrometry (gc-ms) with headspace solid-phase micro extraction (spme) method has been employed for the analysis of the flavor volatiles of three different rice cultivar, including two modified iranian rice cultivars and hashemi rice cultivar during gelatinization. the proposed combination provided a powerful system for easy and rapid screening of a...

2004
R. S. WHITON

Headspace solid-phase microextraction (SPME) is a fast and simple sampling method for analysis of volatile compounds, but quantitation can be affected by sample matrix and sampling conditions. Sampling time and temperature are particularly important in controlling analyte response, and the effects vary for different compound classes and volatilities. Tests with model solutions containing a rang...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2008
Meekin Chai Guanhuat Tan Asha Lal

A headspace solid-phase microextraction method has been developed for the determination of 8 pesticides in vegetables and fruits by using gas chromatography with an electron capture detector. Two types of fibers (polyacrylate, 85 microm and polydimethylsiloxane, 100 microm) have been assayed and compared. The main factors: extraction and desorption parameters, ionic strength, and the effects of...

Journal: :Journal of chromatography. A 2007
Laura Sprunger Amy Proctor William E Acree Michael H Abraham

Water-to-polydimethylsiloxane (PDMS) and gas-to-PDMS sorption coefficients have been compiled for 170 gaseous and organic solutes. Both sets of sorption coefficients were analyzed using the Abraham solvation parameter model. Correlations were obtained for both "dry" headspace solid-phase microextraction and conventional "wet" PDMS coated surfaces. The derived equations correlated the experiment...

Journal: :Molecules 2009
Lin Li Jiancheng Zhao

A total of 38 volatile components were identified in Rhodobryum giganteum (Schwaegr.) Par. collected from two different geographic regions by headspace solid-phase microextraction (HS-SPME), combined with gas chromatography/mass spectrometry (GC/MS). The volatile components included some aliphatic and aromatic aldehydes, monoterpene hydrocarbons and a sesquiterpene (alpha-farnesene), with 1-met...

Journal: :محیط شناسی 0
امیر سالمی -استادیار گروه آلاینده های محیط زیست، پژوهشکدة علوم محیطی، دانشگاه شهید بهشتی پگاه فلاحی کارشناس ارشد مدیریت محیط زیست، پژوهشکدة علوم محیطی، دانشگاه شهید بهشتی عبدالرضا کرباسی استادیار گروه مهندسی محیط زیست، دانشکدة محیط زیست، دانشگاه تهران

in the present work a modified in-tube solid phase microextraction technique followed by gas chromatography-mass spectrometry (gc-ms) has been applied for determination of water odorants. geosmin, 2-methyl isoborneol, 2-isopropyl-3-methoxy pyrazine, 2-isobutyl-3-methoxy pyrazine and 2,4,6-trichloroanisol are of the most important odorants which have been studied. in the described method, analyt...

2005
Shan Zhou Junxiong Huang Xing Gao Liwen Zhao

Solid phase microextraction (SPME) then capillary gas chromatography with mass spectrometric detection have been used for determination of nine phenyl compounds in snow water in Beijing City. Headspace extraction with a fiber coated with 100 lm PDMS was used to extract the compounds. Extraction and desorption times were optimized at 8 and 2 min, respectively. Relative standard deviation (RSD) o...

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