نتایج جستجو برای: headspace sampling

تعداد نتایج: 214473  

2004
Derrick C. Wood James M. Miller

2 Headspace sampling for gas chromatographic (GC) analysis has many advantages, the most important of which is the elimination of many interferences from the sample matrix. In addition to the standard methods for headspace sampling, the technique of solid-phase microextraction (SPME) has found wide acceptance because it is simple and inexpensive. More recently, single-drop microextraction (SDME...

2012

The determination of VOCs is widely used in many fields of chemistry. Two common sample preparation techniques for this analysis are static and dynamic headspace. Static headspace is a relatively simple sampling method that is dependent upon the formation of equilibrium conditions in a closed system. Dynamic headspace continually sweeps the headspace of the sample concentrating the analytes ont...

2003
J. P. Spinhirne J. A. Koziel N. K. Chirase Jacek A. Koziel

A new method for rapid sampling and qualitative characterization of the headspace gases of closed in vitro cultures using solid phase microextraction (SPME) was evaluated for ruminal fluid and ruminal fluid with feed containing a feed additive. Gas sample collection was achieved by exposing a DVB/Carboxen/PDMS 50/30 m SPME fiber to the headspace of cultures for 1 min every hour. This was follow...

2007
Stephanie R. Dungan Susan E. Ebeler

A solid-phase microextraction (SPME) procedure was evaluated for its application in measuring solute release in the headspace (HS) and in the liquid phase (DI) from emulsified and nanostructured materials. Limonene, a hydrophobic flavor compound present in many foods and beverages, was used as a model solute for evaluating the SPME method. Sampling conditions, including SPME fiber type, samplin...

Journal: :Analytical and bioanalytical chemistry 2010
Hanh Lai Alfred Leung Matthew Magee José R Almirall

This study demonstrates the use of solid-phase microextraction (SPME) to extract and pre-concentrate volatile signatures from static air above plastic explosive samples followed by detection using ion mobility spectrometry (IMS) optimized to detect the volatile, non-energetic components rather than the energetic materials. Currently, sample collection for detection by commercial IMS analyzers i...

2002
Glynda Smith

Static headspace analysis can provide reasonably good sensitivity for halogenated hydrocarbons and aromatic compounds. But USEPA Method 524.2 Revision 4 requires the evaluation of several analytes containing different functional groups such as ketones, ethers, and esters. Such compounds can be particularly difficult to analyze at low concentration using static headspace due to the affinity of p...

Journal: :Analytical and bioanalytical chemistry 2006
Lingshuang Cai Jacek A Koziel Jeremiah Davis Yin-Cheung Lo Hongwei Xin

Volatile organic compounds (VOCs) and odors in cattle rumen gas have been characterized by in-vivo headspace sampling by solid-phase microextraction (SPME) and analysis by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). A novel device enabling headspace SPME (HS-SPME) sampling through a cannula was designed, refined, and used to collect rumen gas samples from steers. A Carboxen-pol...

Journal: :Journal of chromatographic science 2006
F Barani N Dell'Amico L Griffone M Santoro C Tarabella

A new analytical method for the determination of halogenated and aromatic volatile organic compounds in groundwater, mineral water, and drinking water at concentrations ranging between 1-10000 ng/L is developed. A new type of headspace sampler that combines static headspace sampling with a trap is used, yielding very low detection limits and good repeatability without carryover effects. An unex...

Journal: :The Journal of experimental biology 2013
Laurent Dormont Jean-Marie Bessière Doyle McKey Anna Cohuet

Odours emitted by human skin are of great interest to biologists in many fields, with practical applications in forensics, health diagnostic tools and the ecology of blood-sucking insect vectors of human disease. Convenient methods are required for sampling human skin volatiles under field conditions. We experimentally compared four modern methods for sampling skin odours: solvent extraction, h...

Journal: :Bio-protocol 2015
Mario Kallenbach Daniel Veit Elisabeth J Eilers Meredith C Schuman

Plant volatiles (PVs) mediate manifold interactions between plants and their biotic and abiotic environments (Dicke and Baldwin, 2010; Holopainen and Gershenzon, 2010). An understanding of the physiological and ecological functions of PVs must therefore be based on measurements of PV emissions under natural conditions. Yet sampling PVs in natural environments is difficult, limited by the need t...

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