Search results for "Microextraction"
showing 10 items of 144 documents
Analysis of furan in coffee of different provenance by head-space solid phase microextraction gas chromatography-mass spectrometry: effect of brewing…
2009
A simple, sensitive and accurate method for the analysis of furan in roasted coffee has been used based on headspace-solid-phase micro-extraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The extraction was performed using 75-microm carboxen/polydimethylsiloxane fiber. Ionic strength, extraction time and temperature, and desorption time were assessed as the most important parameters affecting the HS-SPME procedure and d(4)-furan was used as the internal standard. The linearity range was in the range 0.0075-0.486 ng g(-1); the LOD and LOQ calculated using the signal-to-noise ratio approach were 0.002 and 0.006 ng g(-1), respectively. The inter- and intra-day precisio…
The Off-Flavor of Pea Flour
2014
Pea products are underused as a protein source in human food because of their “beany” flavor. The objective of the study is to select an extraction method being the most representative for the sensory perception of the beany flavor. Solid phase microextraction (SPME) and purge and trap (P&T) extracts were analyzed by GC-MS and the sensory representation of the extracts was assessed by direct gas chromatography-olfactometry (D-GC-O). Extracted compounds were less numerous in SPME extracts than in P&T extracts. Nevertheless, the SPME method was more suitable because of its good representation of the pea suspension odor.
Micropollutants removal in an anaerobic membrane bioreactor and in an aerobic conventional treatment plant
2012
The paper expresses an attempt to tackle the problem due to the presence of micropollutants in wastewater which may be able to disrupt the endocrine system of some organisms. These kinds of compounds are ubiquitously present in municipal wastewater treatment plant (WWTP) effluents. The aim of this paper is to compare the fate of the alkylphenols-APs (4-(tert-octyl)) phenol, t-nonylphenol and 4-p-nonylphenol and the hormones (estrone, 17ß-estradiol and 17¿-ethinylestradiol) in a submerged anaerobic membrane bioreactor (SAMBR) pilot plant and in a conventional activated sludge wastewater treatment plant (CTP). The obtained results are also compared with the results obtained in a previous stud…
Understanding fat, proteins and saliva impact on aroma release from flavoured ice-creams
2017
Publication également référencée sous le numéro WOS:000437803400018; The release profile of fourteen aroma compounds was studied in ice cream samples varying in fat and protein, both in level and type. In vitro aroma release was monitored by solid phase micro-extraction gas chromatography using an innovative saliva reactor, which imitated human chewing under temperature control. The results showed that the effect of the fat type on aroma release was smaller than that of fat level. Ice creams with low fat level released more hydrophobic aroma compounds than ice creams with high fat level. At low fat level more aroma compounds were released from ice creams with lower protein content. At high …
Solid-phase microextraction-liquid chromatography-mass spectrometry applied to the analysis of insecticides in honey
2007
An approach based on solid-phase microextraction-liquid chromatography-mass spectrometry (SPME-LC-MS) has been developed for determining 12 insecticides (bromophos ethyl, chlorpyrifos methyl, chlorpyrifos ethyl, diazinon, fenoxycarb, fonofos, phenthoate, phosalone, pirimiphos methyl, profenofos, pyrazophos, and temephos) in honey. The influence of several parameters on the efficiency of the SPME was systematically investigated. Under optimal conditions, the procedure provided excellent linearity (>0.990), detection and quantification limits (between 0.001 and 0.1 microg g(-1) and between 0.005 and 0.5 microg g(-1), respectively), and precision (<19% at the quantification limits and from 6 t…
Aroma Profiling of Leaf, Flower, Peel and In Vitro Embryo Tissues of “Ciaculli Late” Mandarin
2003
Abstract Volatile compounds released from leaf, flower and peel as well as from somatic (nucellar) embryo tissues of “Tardivo di Ciaculli” or “Ciaculli late” mandarin have been collected/ concentrated by headspace solid phase microextraction, HS-SPME, and analyzed by GC-MS. The tehnique allowed the rapid comparison of the volatiles from the various sources; in particular, 19 compounds were identified for the embryos, 16 for leaf and flower and 13 for peel. Limonene was the most abundant volatile component of the embryo and peel while γ-terpinene was the major compound among volatiles from leaf and flower. Relatively high amounts of methyl N-methyl anthranilate and β-caryophyllene were also …
Stir bar sorptive-dispersive microextraction for trace determination of triphenyl and diphenyl phosphate in urine of nail polish users
2018
Abstract This work describes a new analytical method useful for monitoring the human exposure to the endocrine-disrupting plasticizer triphenyl phosphate (TPP) via nail polish use. The method allows trace determination of this parent compound and its main metabolite, namely diphenyl phosphate (DPP), in urine samples of nail polish users. The method is based on a novel microextraction technique termed stir bar sorptive-dispersive microextraction (SBSDME) using a magnetic composite made of CoFe2O4 magnetic nanoparticles embedded into a mixed-mode weak anion exchange polymer (Strata™-X-AW), followed by liquid chromatography-tandem mass spectrometry (LC–MS/MS). The main parameters involved in t…
The application of molecular imprinting technology to solid phase extraction
2001
In parallel to a long lasting search for universal multi-purpose sorbents, the area of solid phase extraction (SPE) is recently experiencing a rapid development of new types of tailor-made class specific or compound-specific sorbents which are designed to respond to the increasing demand for selectivity and efficiency in sample clean-up prior to quantification. An important issue here is the enrichment and clean-up of complex samples, such as environmental waters, sediments, biofluids and foodstuffs prior to detection. This because the analyte is often present in low concentration in a complex mixture of similar compounds and therefore needs to be isolated and enriched in order to be detect…
A fatal case of a paint thinner ingestion: Comparison between toxicological and histological findings
2010
Toluene and xylene are aromatic hydrocarbons commonly used as an industrial solvent for the manufacturing of pharmaceuticals, paints, and chemicals. The Occupational Safety and Health Administration has determined that toluene levels of 2000 parts per million (ppm) are considered dangerous to life and health. Several studies have examined the absorption of toluene and xylene following inhalation and oral ingestion in humans. Volatile organic compounds that are absorbed into the blood are distributed throughout the body; in particular, distribution of absorbed toluene and xylene in humans and rodents is characterized by preferential uptake in well-perfused and lipophil tissues such as the br…
Determination of benzophenone-3 and its main metabolites in human serum by dispersive liquid–liquid microextraction followed by liquid chromatography…
2013
A new analytical method for the determination of benzophenone-3 (2-hydroxy-4-methoxybenzophenone), and its main metabolites (2,4-dihydroxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone) in human serum is presented. The method is based on dispersive liquid-liquid microextraction (DLLME) as preconcentration and clean-up technique, followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Acidic hydrolysis and protein precipitation with HCl 6 M (1:1) (100 °C, 1 h) were carried out before extraction. The variables involved in the DLLME process were studied. Under the optimized conditions, 70 µL of acetone (disperser solvent) and 30 µL of chloroform (extraction solvent) were …