نتایج جستجو برای: spme solid
تعداد نتایج: 190012 فیلتر نتایج به سال:
The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the influence of magnetic forces over the extraction efficiency of triazines using superparamagne...
This study presents the preparation and characterization of a nanoscale Davankov-type hyper-crosslinked-polymer (HCP) as an adsorbent of benzene-ring-containing dyes and organic pollutants. HCP nanoparticles post-crosslinked from a poly(DVB-co-VBC) precursor were synthesized in this study, possessing ultrahigh surface area, hydrophobicity and stability. The as-synthesized Davankov-type HCP exhi...
Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) has been developed, optimized, and applied to investigate the dimethylsulfide (DMS) emissions from eight marine phytoplankton species, namely, Calcidiscus leptoporus, Emiliania huxleyi, Phaeodactylum tricornutum, Chaetoceros neogracilis, Dunaliella tertiolecta, Synechococcus, Prochlorococcu...
The coupling of disposable solid-phase microextraction (SPME) with performance reference compounds (PRCs) has been recently introduced to measure time-averaged freely dissolved concentrations (Cfree) of hydrophobic organic contaminants in sediments under laboratory conditions. To explore the use of PRC-SPME for in situ sampling in seawater, disposable PDMS fibers (35-μm and 100-μm coating) prel...
The aroma profile of cocoa products was investigated by headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). SPME fibers coated with 100 microm polydimethylsiloxane coating (PDMS), 65 microm polydimethylsiloxane/divinylbenzene coating (PDMS-DVB), 75 microm carboxen/polydimethylsiloxane coating (CAR-PDMS) and 50/30 microm divinylbenzene/car...
Aromatic amines are an important class of harmful components of cigarette smoke. Nevertheless, only few of them have been reported to occur in urine, which raises questions on the fate of these compounds in the human body. Here we report on the results of a new analytical method, in situ derivatization solid phase microextraction (SPME) multi-dimensional gas chromatography mass spectrometry (GC...
Comparison of chemical approaches for assessing bioavailability of sediment-associated contaminants.
Two chemical approaches, Tenax extraction and matrix solid-phase microextraction (matrix-SPME), were compared to assess the bioavailability of hydrophobic contaminants from sediment. Hexachlorobiphenyl, DDE, permethrin, chlorpyrifos, and phenanthrene were individually spiked into two sediments differing in physical characteristics. Bioaccumulation was determined by exposing the oligochaete, Lum...
Environmental and health aspects of road materials have been discussed for a long time, mostly regarding bitumen and bitumen fumes. However, just a few studies on other types of road materials have been reported. In this doctoral study, two types of materials, asphalt release agents and bituminous sealants, were investigated with regard to chemical characterization and emission profiles. Beside...
BACKGROUND, AIM, AND SCOPE Polycyclic aromatic hydrocarbons (PAHs) are often found in oily wastewaters. Their presence is usually the result of human activities and has a negative effect on the environment. One important step in addressing this problem is to evaluate the effectiveness of PAH removal by biological processes since these are the most cost-effective treatments known today. Many tec...
Smokeless powder additives are usually detected from an extraction of post-blast residues or unburned powder particles followed by chromatographic analyses. This work presents the first comprehensive study of the detection of volatile and semi-volatile additives of smokeless powders using solid phase microextraction (SPME) as a sampling and pre-concentration technique. The goal of this study is...
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