نتایج جستجو برای: spme solid
تعداد نتایج: 190012 فیلتر نتایج به سال:
since solid-phase and liquid-phase microextraction (spme and lpme) were introduced, as effective solvent-free methods, many efforts have been made to improve their modes and applications. however, due to limitations with sensitivity and efficiency, researchers have focused on improving the performance of their basic primary modes. in this way, in recent years, different methods such as ultrason...
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...
This work examines a newly developed dynamic air sampling technique, known as HighSurface Area Solid Phase Micro Extraction (HSA-SPME), in sampling and analysis of chemical warfare agent surrogate and degradation compounds. The polymer coating of this device has 10 times the surface area of commercially available SPME fibers, and at high sample flow rates (4 L·min) provided increased extraction...
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)...
A headspace solid-phase microextraction (HS-SPME) method is developed for the determination of styrene in drinking water. Gas chromatography (GC)-mass spectrometry is utilized for qualitative analysis. A manual SPME holder with 85-microm polyacrylate coating is used to extract the styrene from water, which is determined to have good linearity (correlation coefficient r = 0.9999 for 1.00-100.00 ...
Ultrasonic assist with headspace solid phase microextraction (UA-HS-SPME) have been applied, for the first time, for the extraction of volatile organic compounds of Carum carvi L. from Iran. The oils obtained were analyzed by GC–MS. Different experimental parameters such as fiber's coating type, sonication time, extraction time and temperature, and desorption time were investigated. Results sho...
A solid-phase microextraction (SPME) sampling method is developed to evaluate indoor exposure to benzene, toluene, ethylbenzene, xylene, and styrene with gas chromatography and flame ionization detection for quantitative analysis. An SPME holder with a 100-pm polydimethylsiloxane (PDMS) and 65-pm PDMS-divinylbenzene fiber coating is tested in different air relative humidity conditions. The meth...
Solid phase microextraction (SPME) has been optimized and applied to the determination of the volatile halogenated compounds (VHCs) and semi-volatile halogenated compounds (SVHCs). Three types of SPME fiber coated with different stationary phases (PDMS-100 mum, CAR/PDMS-75 mum, PDMS/DVB-65 mum) were used to examine their extraction efficiencies for the compounds tested. Experimental parameters ...
Manual solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry is investigated as a possible alternative for the determination of petroleum hydrocarbons in soils. Spiked onto an agricultural soil is a commercial diesel fuel (DF) with the following composition by weight: 12% linear alkanes, 52% saturated hydrocarbons (branched and cyclic), 21% alkylated aromatic hydr...
a fiber coating from polyaniline (pani) was electrochemically prepared and employed for solid phase micreoextraction (spme). the pani film was directly electrodeposited on the platinum wire surface using cyclic voltametry (cv) technique. the same method was applied for the preparation of spme fiber coated by polyaniline multiwalled carbon nanotubes (pani/mwcnts) composite. the concentration of ...
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