نتایج جستجو برای: assisted headspace spme ua
تعداد نتایج: 139598 فیلتر نتایج به سال:
Two simple methods using headspace solid-phase microextraction (HS-SPME) coupled to a gas chromatograph with a flame ionization detector were compared for the determination of polycyclic aromatic hydrocarbons (PAH) in soils. These compounds were included in the US Environmental Protection Agency's Priority Pollutants list. Direct hot water HS-SPME extraction and sonication organic extraction fo...
Volatile components from Rhizoma Alpiniae Officinarum were respectively extracted by three methods including hydrodistillation, headspace solid-phase microextraction (HS-SPME) and diethyl ether extraction. A total of 40 (hydrodistillation), 32 (HS-SPME) and 37 (diethyl ether extraction) compounds were respectively identified by gas chromatography-mass spectrometry (GC/MS) and 22 compounds were ...
A headspace solid-phase microextraction (HS-SPME), in conjunction with gas chromatography-flame ionization detection for use in the determination of six frequently used glycol ethers at the microg/l level is described. A 75 microm Carboxenpolydimethylsiloxane fiber was used to extract the analytes from an aqueous solution. Experimental HS-SPME parameters such as extraction temperature, extracti...
In this paper, a headspace solid-phase microextraction (HS-SPME) method was applied to analyse the volatile compounds in a traditional Chinese medicine (TCM), Rhioxma Curcumae Aeruginosae. SPME parameters such as fibers, extraction temperature, extraction time and desorption time were investigated. Thirty-five volatile compounds were separated and identified. Relative standard deviations (RSDs)...
The main objective of this contribution is to describe the fundamental concepts associated with solid-phase microextraction (SPME). Theory provides insight when developing SPME methods and identifies parameters for rigorous control and optimization. A mathematical model has been developed to understand the principal processes of SPME by applying basic fundamental principles of thermodynamics an...
In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by ...
background: determination of organic pollutants usually requires extraction of the pollutants from samples, using hazardous solvent. solid phase micro-extraction (spme) is a solvent-free equilibrium extraction method, in which, proper calibration can allow quantitative measurements of organic pollutants at a very good sensitivity without the use of any organic solvent. because individual voc...
This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the ...
Solid-phase microextraction (SPME) is an organic solvent-free sample preparation tool suitable for direct adsorption of analytes from the headspace or the aqueous phase of a matrix followed by desorption into a gas chromatograph (GC) or high-performance liquid chromatograph (HPLC) for subsequent analysis. The SPME technique is designed to accommodate the use of fibers coated with different poly...
The diagnostic potential and health implications of volatile organic compounds (VOCs) present in human feces has begun to receive considerable attention. Headspace solid-phase microextraction (SPME) has greatly facilitated the isolation and analysis of VOCs from human feces. Pioneering human fecal VOC metabolomic investigations have utilized a single SPME fiber type for analyte extraction and a...
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