Read by QxMD icon Read


Justen J Poole, Jonathan J Grandy, Miao Yu, Ezel Boyaci, German A Gomez Rios, Nathaly Reyes-Garcés, Barbara Bojko, Harmen Vander Heide, Janusz Pawliszyn
To date, solid-phase microextraction (SPME) fibers used for in-vivo bio-analysis can be too fragile and flexible, which limits suitability for direct tissue sampling. As a result, these devices often require a sheathing needle to pre-puncture robust sample matrices and protect the extraction phase from mechanical damage. To address this limitation, a new SPME device is herein presented which incorporates an extraction phase recessed into the body of a solid needle. This device requires no additional support or shielding during puncture events through protective tissue...
May 26, 2017: Analytical Chemistry
Habib Razmi, Elnaz Marzi Khosrowshahi, Samaneh Farrokhzadeh
In this study, a tiny coiled cupper wire as a novel solid phase microextraction (SPME) fiber was coated with mesoporous silica/cetyltrimethylammonium bromide (MCM-41/CTAB) as an adsorbent by electrochemically assisted self-assembly method and used for the preconcentration of polycyclic aromatic hydrocarbons (PAHs) as model analytes prior to chromatographic determination. Deposition of MCM-41/CTAB on the coiled SPME (C-SPME) fiber resulted in easily controlled and reproducible SPME coatings. Non-calcined MCM-41/CTAB on C-SPME plays a key role in the adsorption of PAHs...
April 9, 2017: Journal of Chromatography. A
German Augusto Gómez-Ríos, Emanuela Gionfriddo, Justen J Poole, Janusz Pawliszyn
The direct interface of microextraction technologies to Mass Spectrometry (MS) has unquestionably revolutionized the speed and efficacy at which complex matrices are analyzed. Solid Phase Micro Extraction-Transmission Mode (SPME-TM) is a technology conceived as an effective synergy between sample preparation and ambient ionization. Succinctly, the device consists of a mesh coated with polymeric particles that extract analytes of interest present in a given sample matrix. This coated-mesh acts as a transmission mode substrate for Direct Analysis in Real Time (DART), allowing for rapid and efficient thermal-desorption/ionization of analytes previously concentrated on the coating, and dramatically lowering limits of detection attained by sole DART analysis...
May 25, 2017: Analytical Chemistry
Petr Doležal, Pavlína Kyjaková, Irena Valterová, Štěpán Urban
Instrumental human scent analysis is undoubtedly desirable for many forensic as well medical applications. Most of the previous human scent studies were focused on volatile organic compounds (VOCs) which were analysed by head space solid phase micro-extraction gas chromatography/mass spectrometry (HS-SPME-GC/MS). This method is, however, significantly less sensitive to "heavier" less volatile compounds emitted from the human skin. These less volatile organic scent molecules probably create the basis of the individual human scent signature, and therefore, our attention is focused mainly on these "heavier" compounds...
May 1, 2017: Journal of Chromatography. A
Andrea Speltini, Andrea Scalabrini, Federica Maraschi, Michela Sturini, Antonella Profumo
This paper presents an overview of the recent applications of molecularly imprinted polymers (MIPs) to sample preparation. The review is thought to cover analytical procedures for extraction of contaminants (mainly illegal/noxious organic compounds) from food and environmental matrices, with a particular focus on the various pre-concentration/cleanup techniques, that is offline and online solid-phase extraction (SPE), dispersive SPE (d-SPE), magnetic SPE (MSPE), solid-phase microextraction (SPME) and stir-bar sorptive extraction (SBSE), applied before instrumental quantification...
June 29, 2017: Analytica Chimica Acta
Kamila Kędziora, Wiesław Wasiak
Analysis of trace compounds in complex matrices requires a preliminary step of sample preparation. From among widely used methodologies, microextraction techniques have become increasingly important as they tend towards being environmentally friendly. The needle trap (NT) extraction is a relatively new and promising technique which combines sampling, sample preparation and sample introduction. The core of the needle trap device is a suitable sorbent material packed inside the needle, that determines selectivity and efficiency of the method...
May 12, 2017: Journal of Chromatography. A
Dana Bors, John Goodpaster
Quantitating post-blast explosive residue is not a common practice in crime labs as it is typically not legally relevant. There is value in quantitation, however, if the distribution of residues on Improvised Explosive Devices (IEDs) can help guide future sample collection and/or method development. Total vaporization solid phase microextraction gas chromatography mass spectrometry (TV-SPME/GC/MS) was used to quantify residues of double-base smokeless powder (DBSP), which includes nitroglycerin (NG), diphenylamine (DPA), and ethyl centralite (EC) on post-blast PVC pipe bomb fragments...
April 14, 2017: Forensic Science International
Rocco Longo, John W Blackman, Guillaume Antalick, Peter J Torley, Suzy Y Rogiers, Leigh M Schmidtke
BACKGROUND: Lower alcohol wines often have a poor reputation among consumers, in part due to their unsatisfactory flavours such as reduced overall aroma intensity or herbaceous characters. The aim of this study, performed on Verdelho and Petit Verdot, was to quantify the effectiveness of a monovarietal blend in which wines made from less ripe grapes were blended with an equivalent volume of a wine vinified from riper fruit to produce wines with a lower alcohol content and desirable ripe fruit flavours...
May 15, 2017: Journal of the Science of Food and Agriculture
Bi-Cheng Yang, Shu-Fen Fang, Xiao-Ju Wan, Yong Luo, Jiang-Yan Zhou, You Li, Yun-Jun Li, Feng Wang, Ou-Ping Huang
Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with carcinogenic effect raising worldwide concerns. Hydroxylated PAHs (OH-PAHs) could be formed in the body as metabolites of PAHs in human urine samples and thus considered as biomarkers of PAH exposure. In this study, five OH-PAHs including 3-phenanthrol, 1-naphthol, 2-hydroxy fluorene, 1-hydroxprene and 6-hydroxy chrysene in human urine samples were selectively enriched by C18 solid-phase microextraction (SPME), then SPME fiber was connected high voltage and then was inserted into a glass-capillary to elute and ionize the analytes for mass spectrometric (MS) detection...
June 22, 2017: Analytica Chimica Acta
Mohammad Saraji, Ali Shahvar
An iron-based metal-organic aerogel was synthesized using metal-organic framework nanoparticles and applied as a fiber coating for solid-phase microextraction (SPME). Chemical, thermal and morphological characteristics of the material were investigated. Headspace SPME followed by gas chromatography-electron capture detection was used for the determination of chlorobenzenes in the environmental samples. The key experimental factors affecting the extraction efficiency of the analytes, such as ionic strength, extraction and desorption temperature, and extraction time were investigated and optimized...
June 22, 2017: Analytica Chimica Acta
Xu Ling, Zilin Chen
Conductive composite films composed of poly (3, 4-ethylenedioxythiophene) (PEDOT) and sulfonated graphene were electrochemically deposited on carbon fiber bundle in aqueous solutions for solid phase microextraction (SPME). During the electro-polymerization process, negatively charged sulfonated graphene were doped in PEDOT layer and uniformly dispersed in the composite. The modified carbon fiber bundle worked as sorbent was then successfully applied to online SPME-HPLC-UV analysis of jasmonates in wintersweet flowers...
August 1, 2017: Talanta
Guan-Hua Wang, Yong-Qian Lei
Direct head-space solid-phase microextraction (HS-SPME) of phenols in water is usually difficult due to its polarity and solubility in aqueous matrix. Herein we report the fabrication of metal-organic framework MOF-177 coated stainless steel fiber for the HS-SPME of phenols (2-methylolphenol, 4-methylolphenol, 2,4-dimethylolphenol, 2,4-dichlorphenol, and 3-methyl-4-chlorophenol) in environmental water samples prior to the gas chromatography-mass spectrometry detection. Several parameters affecting the extraction efficiency were optimized in the experiment, including extraction temperature and time, the pH value and salt addition...
May 12, 2017: Bulletin of Environmental Contamination and Toxicology
Brian Farneti, Iuliia Khomenko, Marcella Grisenti, Matteo Ajelli, Emanuela Betta, Alberto Alarcon Algarra, Luca Cappellin, Eugenio Aprea, Flavia Gasperi, Franco Biasioli, Lara Giongo
Blueberry (Vaccinium spp.) fruit consumption has increased over the last 5 years, becoming the second most important soft fruit species after strawberry. Despite the possible economic and sensory impact, the blueberry volatile organic compound (VOC) composition has been poorly investigated. Thus, the great impact of the aroma on fruit marketability stimulates the need to step forward in the understanding of this quality trait. Beside the strong effect of ripening, blueberry aroma profile also varies due to the broad genetic differences among Vaccinium species that have been differently introgressed in modern commercial cultivars through breeding activity...
2017: Frontiers in Plant Science
Jacek A Koziel, Lam T Nguyen, Thomas D Glanville, Heekwon Ahn, Timothy S Frana, J Hans van Leeuwen
A passive sampling method, using retracted solid-phase microextraction (SPME) - gas chromatography-mass spectrometry and time-weighted averaging, was developed and validated for tracking marker volatile organic compounds (VOCs) emitted during aerobic digestion of biohazardous animal tissue. The retracted SPME configuration protects the fragile fiber from buffeting by the process gas stream, and it requires less equipment and is potentially more biosecure than conventional active sampling methods. VOC concentrations predicted via a model based on Fick's first law of diffusion were within 6...
October 1, 2017: Food Chemistry
Bárbara Nieva-Echevarría, Encarnación Goicoechea, María D Guillén
The extent of cod liver oil hydrolysis and oxidation during in vitro gastrointestinal digestion was investigated by Proton Nuclear Magnetic Resonance ((1)H NMR) and Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). These techniques evidenced the degradation of polyunsaturated ω-3 and ω-6 lipids and, for the first time, that of vitamin A, naturally present in cod liver oil. Cis,trans-conjugated dienes associated with hydroperoxides, as well as monoepoxides, cis,trans-2,4-alkadienals, 4-hydroperoxy- and 4-hydroxy-2-alkenals, and several vitamin A derived metabolites were generated...
October 1, 2017: Food Chemistry
Igor Lukić, Cesare Lotti, Urska Vrhovsek
Recently, various technologies which utilise fermentation with skins have been developed for obtaining distinct white wines. This study first reports the dynamic changes of volatiles and phenols that occur during skin fermentation in white winemaking. Volatiles were analysed by solid-phase extraction (SPE), solid-phase microextraction (SPME) and gas chromatography (GC), and phenols by ultra-performance liquid chromatography (UPLC), both with mass spectrometric detection. Monoterpenols increased during the first 3days of skin fermentation, after which certain glycosides decreased, but were higher than in control...
October 1, 2017: Food Chemistry
Fang Donglu, Yang Wenjian, Benard Muinde Kimatu, Zhao Liyan, An Xinxin, Hu Qiuhui
To clarify the dynamic changes of flavour components in mushrooms packed with different packaging materials during storage, comprehensive flavour characterization, non-volatile and volatile compounds of Flammulina velutipes were evaluated using electronic nose (E-nose), electronic tongue (E-tongue) technology and headspace solid phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS), respectively. Results showed that volatile compounds of fresh F. velutipes mainly consisted of ketones and alcohols, with 3-octanone being the predominant compound...
October 1, 2017: Food Chemistry
Leonard Böhm, Rolf-Alexander Düring, Hans-Jörg Bruckert, Christian Schlechtriem
With regard to a refinement of water analysis in fish bioconcentration studies, automated solidy-phase microextraction (SPME) was used as alternative approach to conventional solvent extraction (liquid-liquid extraction, LLE) for the extraction of 3 hydrophobic organic chemicals (HOCs) (log KOW 5.5-7.8) from flow-through studies with rainbow trout (Oncorhynchus mykiss). Results proved that total concentrations extracted by SPME combined with internal standards and LLE are equal. Results further verify the possibility for a simultaneous extraction of total and freely dissolved HOC concentrations by SPME...
May 10, 2017: Environmental Toxicology and Chemistry
Carl Taylor, Fraser Lough, Stephen P Stanforth, Edward C Schwalbe, Ian A Fowlis, John R Dean
Listeria monocytogenes is a Gram-positive bacterium and an opportunistic food-borne pathogen which poses significant risk to the immune-compromised and pregnant due to the increased likelihood of acquiring infection and potential transmission of infection to the unborn child. Conventional methods of analysis suffer from either long turn-around times or lack the ability to discriminate between Listeria spp. reliably. This paper investigates an alternative method of detecting Listeria spp. using two novel enzyme substrates that liberate exogenous volatile organic compounds in the presence of α-mannosidase and D-alanyl aminopeptidase...
May 8, 2017: Analytical and Bioanalytical Chemistry
Mohamed A Farag, Sara E Ali, Rashad H Hodaya, Hesham R El-Seedi, Haider N Sultani, Annegret Laub, Tarek F Eissa, Fouad O F Abou-Zaid, Ludger A Wessjohann
Plants of the Allium genus produce sulphur compounds that give them a characteristic (alliaceous) flavour and mediate for their medicinal use. In this study, the chemical composition and antimicrobial properties of Allium cepa red cv. and A. sativum in the context of three different drying processes were assessed using metabolomics. Bulbs were dried using either microwave, air drying, or freeze drying and further subjected to chemical analysis of their composition of volatile and non-volatile metabolites. Volatiles were collected using solid phase micro-extraction (SPME) coupled to gas chromatography-mass spectrometry (GC/MS) with 42 identified volatiles including 30 sulphur compounds, four nitriles, three aromatics, and three esters...
May 8, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"