نتایج جستجو برای: spme solid

تعداد نتایج: 190012  

2006
Maggie Ka-Yi LI Ka-Ho LAM Hongxia YU Michael Hon-Wah LAM

Introduction. Polybrominated diphenyl ethers (PBDEs) are undoubtedly the most important group of organohalogenated compounds that captures the attention of environmental scientists in recent years. PBDEs are widely used flame retardant additives in polymers and textiles and are present in nearly all of our daily appliances. There are growing evidences that these brominated flame retardants are ...

2004
Y. Zeng David Tsukada James A. Noblet Jian Peng

ABSTRACT Despite the growing popularity of solid-phase microextraction (SPME) among the community of analytical chemists, applications of SPME in the measurement of very hydrophobic organic compounds (VHOCs) have remained limited. This is due, in part, to the difficulty of calibrating SPME devices for VHOCs. Here, we present an analytical procedure used to determine the distribution coefficient...

Journal: :Molecules 2014
Jiyuan Zhang Mun-Wai Cheong Bin Yu Philip Curran Weibiao Zhou

The application of headspace-solid phase microextraction (HS-SPME) has been widely used in various fields as a simple and versatile method, yet challenging in quantification. In order to improve the reproducibility in quantification, a mathematical model with its root in psychological modeling and chemical reactor modeling was developed, describing the kinetic behavior of aroma active compounds...

Introduction: In this research the solid phase micro extraction (SPME) for sampling and determination of carbon tetrachloride and chloroform in air was developed and effect of ambient parameters on SPME was assessed. Methods: For this purpose standard chamber was built in the laboratory. The concentrations of compounds in the chamber were measured with SPME. The optimum condition for extract...

Journal: :analytical and bioanalytical chemistry research 2014
akram rahimi payman hashemi gholam reza talei mohammad borzuei ali reza ghiasvand

the volatile components of citrus aurantium l. flowers were characterized by gc-ms with two different extraction techniques, hydrodistillation (hd) and ultrasonic-assisted headspace solid phase microextraction (ua-hs-spme). in the spme method, the volatile components of the samples, irradiated by ultrasonic radiation, were collected on a polydimethyl siloxane (pdms) commercial fiber as well as ...

2006
Yan Wang

The use of laser desorption as a sample introduction method for solid-phase microextraction (SPME) has been investigated in this research project. Three different types of analytical instruments, mass spectrometry (MS), ion mobility spectrometry (IMS) and gas chromatography (GC) were employed as detectors. The coupling of laser desorption SPME to these three instruments was constructed and desc...

Journal: :Journal of forensic sciences 2011
Patricia J Giebink Ruth Waddell Smith

Organic impurity profiling of seized 3,4-methylenedioxymethamphetamine (MDMA) tablets aims to link tablets to common production sources. Conventionally, organic impurities are extracted from tablets using a liquid-liquid extraction (LLE) procedure prior to analysis by gas chromatography-mass spectrometry (GC-MS). In this research, the development of an alternative microwave-assisted extraction/...

Journal: :Analytical chemistry 2010
Xiang Li Gangfeng Ouyang Heather Lord Janusz Pawliszyn

Previous aerosol studies utilizing solid-phase microextraction (SPME) predominantly focused on volatile and semivolatile compounds in the gaseous phase. Difficulties were associated with quantitative analysis of these compounds when they were associated with atmospheric particles. The present study combines SPME technology with that of carboxen packed needles (needle trap, NT) for analysis of g...

Journal: :Journal of chromatographic science 2006
Annamaria Halasz Jalal Hawari

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...

2011
Emma Dixon Cynthia Clubb Sara Pittman Larry Ammann Zeehasham Rasheed Nazia Kazmi Ali Keshavarzian Pat Gillevet Huzefa Rangwala Robin D. Couch

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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