نتایج جستجو برای: assisted headspace spme ua
تعداد نتایج: 139598 فیلتر نتایج به سال:
The volatile compounds from various parts of Echinops ilicifolius (Compositae) such as flowers, leaves and roots obtained by hydrodistillation (HD) and headspace solid-phase microextraction (HS-SPME) methods were subsequently analysed by GC and GC/MS and compared. Thirty-seven and 20 components of the flower of E. ilicifolius were characterized, representing 99.7% and 100.0% of the total compos...
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...
The sensitivity and precision of headspace solid-phase micro extraction (HS-SPME) at an analyte solution temperature (T (as)) of +35 degrees C and a fiber temperature (T (fiber)) of +5 degrees C were compared with those for HS-SPME at T (as) and T (fiber) of -20 degrees C for analysis of the volatile organic compounds benzene, 1,1,1-trichloroethane, trichloroethylene, toluene, o-xylene, ethylbe...
Background: Melanoma is the most serious form of skin cancer and it has the highest rate of growth among different types of cancers. Ursolic acid (UA), a natural pentacyclic triterpenoid, is a major bioactive compound in several traditional medicinal plants including pomegranate (Punica granatum L.) flower. UA has very important biological and pharmacological functions. Objective: In this study...
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...
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...
In this work, the volatile profiles of smoked and non-smoked Iranian rice were identified, and their relative abundance was calculated and compared. Headspace solid-phase microextraction together with gas chromatography-mass spectrometry (SPME-GC-MS) were used to extract and identify the volatile compounds. The main groups of volatiles in Iranian rice were aldehydes, ketones, phenol derivatives...
T198923 ©1998 Sigma-Aldrich Co. Solid phase microextraction, a simple, effective adsorption/ desorption technique, eliminates the need for solvents or complicated apparatus for concentrating volatile or nonvolatile compounds in liquid samples or headspace. SPME is compatible with analyte separation/detection by gas chromatography or HPLC, and provides linear results for wide concentrations of a...
Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography/mass spectrometry (GC/MS) method was developed to determine 3-chloropropane-1,2-diol (3-MCPD) in hydrolyzed vegetable protein and Chinese soy sauce. The 3-MCPD was firstly derivativized with phenylboronic acid in aqueous solution at 90 degrees C for 10 min, then extracted by HS-SPME and finally detected with GC/MS, ...
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