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Gabriele Serreli, Igor Jerković, Katarzyna Angelika Gil, Zvonimir Marijanović, Viviana Pacini, Carlo Ignazio Giovanni Tuberoso
The aim of this research was to evaluate the antioxidant capacity and physical-chemical characteristics of commercial white myrtle berry (Myrtus communis L. var. leucocarpa DC) liqueur (WMBL). The total phenolic (TP) content was measured spectrophotometrically, applying a modified Folin-Ciocalteu's method, and phenolic compounds were identified by high-performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry, and quantified by HPLC coupled with ultraviolet/visible detection. The antioxidant capacities were evaluated by FRAP, CUPRAC, DPPH(•), and ABTS(•+) assays...
April 26, 2017: Plant Foods for Human Nutrition
Mario F Mirabelli, Jan-Christoph Wolf, Renato Zenobi
In this study, a gas chromatography (GC) system was interfaced to a high-resolution Orbitrap mass spectrometer by means of an active capillary plasma ionization source, based on dielectric barrier discharge ionization (DBDI). This allowed highly efficient soft ionization of gas-phase, chromatographically resolved compounds at ambient pressure. Several pesticides and illicit drugs were analyzed, and the limits of detections (LODs) were as low as 30 pg mL(-1) for the GC-DBDI-MS coupling (corresponding to 60 fg on-column sensitivity) and 30 fg mL(-1) for SPME-GC-DBDI-MS...
April 26, 2017: Analyst
Susana Ramírez-Guízar, Hannah Sykes, John D Perry, Edward C Schwalbe, Stephen P Stanforth, Ma Cristina I Perez-Perez, John R Dean
This paper utilized L-alanine aminopeptidase activity as a useful approach to distinguish between Gram-negative and Gram-positive bacteria. This was done using two enzyme substrates, specifically 2-amino-N-phenylpropanamide and 2-amino-N-(4-methylphenyl)propanamide which liberated the volatile compounds aniline and p-toluidine, respectively. Two complementary analytical techniques have been used to identify and quantify the VOCs, specifically static headspace multicapillary column gas chromatography ion mobility spectrometry (SHS-MCC-GC-IMS) and headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS)...
April 12, 2017: Journal of Chromatography. A
Bogusław Buszewski, Maciej Milanowski, Tomasz Ligor, Paweł Pomastowski
The aim of the study was determination of bacterial viability in saliva samples and finding a correlation between microbiological and volatile profiles of saliva depending on incubation time. Bacteria colonizing healthy oral cavities were also identified. Twelve healthy adults donated unstimulated saliva samples. Flow cytometry, optical density measurements and colony-forming unit (CFU) counting method were employed for analyses of native and inoculated saliva after 0, 1, 2, 24 and 48 h of incubation. Volatile profiles were acquired using headspace-solid phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS)...
April 21, 2017: Electrophoresis
Gaalebalwe Ntlhokwe, Andreas G J Tredoux, Tadeusz Górecki, Matthew Edwards, Jochen Vestner, Magdalena Muller, Lené Erasmus, Elizabeth Joubert, J Christel Cronje, André de Villiers
The applicability of comprehensive two-dimensional gas chromatography (GC×GC) using a single-stage thermal modulator was explored for the analysis of honeybush tea (Cyclopia spp.) volatile compounds. Headspace solid phase micro-extraction (HS-SPME) was used in combination with GC×GC separation on a non-polar × polar column set with flame ionisation (FID) detection for the analysis of fermented Cyclopia maculata, Cyclopia subternata and Cyclopia genistoides tea infusions of a single harvest season. Method optimisation entailed evaluation of the effects of several experimental parameters on the performance of the modulator, the choice of columns in both dimensions, as well as the HS-SPME extraction fibre...
April 17, 2017: Analytical and Bioanalytical Chemistry
Yu Tian, Juanjuan Feng, Yanan Bu, Xiuqin Wang, Chuannan Luo, Min Sun
Titanium dioxide nanorods were prepared on the surface of titanium wire by hydrothermal synthesis for use as a solid-phase microextraction (SPME) fiber. The morphology of the SPME coating was observed by scanning electron microscopy (SEM). Employed in conjunction with gas chromatography (GC), the fiber was investigated with five polycyclic aromatic hydrocarbons (PAHs) and three terphenyls in direct-immersion extraction mode. Various parameters were optimized, such as the extraction time, the stirring rate, the extraction temperature, the ionic strength of the sample solution, and the desorption time...
April 17, 2017: Analytical and Bioanalytical Chemistry
Laura Oliveira Lago, Karine Primieri Nicolli, Aline Biasoto Marques, Claudia Alcaraz Zini, Juliane Elisa Welke
The validated method based on the use of headspace solid phase microextraction (HS-SPME) coupled with the comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC/TOFMS) proved to be appropriate for this first simultaneous quantitative determination of six toxic compounds (formaldehyde, acetaldehyde, ethyl carbamate, furan, furfural and acrolein) found in wines. Acetaldehyde and acrolein coeluted with other wine compounds, which indicated that difficulties could arise if only one-dimensional gas chromatography was used for the determination of these compounds...
September 1, 2017: Food Chemistry
William Kranz, Clinton Carroll, Darren A Dixon, John V Goodpaster, Christine J Picard
Alternative methods for the identification of species of blow fly pupae have been developed over the years that consist of the analyses of chemical profiles. However, the effect of biotic and abiotic factors that could influence the predictive manner for the tests have not been evaluated. The lipids of blowfly pupae (Cochliomyia macellaria, Lucilia cuprina, Lucilia sericata, and Phormia regina) were extracted in pentane, derivatized, and analyzed by total-vaporization solid phase microextraction gas chromatography-mass spectrometry (TV-SPME GC-MS)...
April 11, 2017: Insects
Alison G Simon, DeEtta K Mills, Kenneth G Furton
Raffaelea lauricola, a fungus causing a vascular wilt (laurel wilt) in Lauraceae trees, was introduced into the United States in the early 2000s. It has devastated forests in the Southeast and has now moved into the commercial avocado groves in southern Florida. Trained detection canines are currently one of the few successful methods for early detection of pre-symptomatic diseased trees. In order to achieve the universal and frequent training required to have successful detection canines, it is desirable to create accessible, safe, and long-lasting training aids...
June 1, 2017: Talanta
Shuyao Huang, Jianqiao Xu, Jiayi Wu, Haojia Hong, Guosheng Chen, Ruifen Jiang, Fang Zhu, Yuan Liu, Gangfeng Ouyang
The concentration of five rapidly metabolized anesthetics in living tilapias was determined in this study, by the presented method coupling in vivo solid phase microextraction (SPME) to gas chromatography-mass spectrometry (GC-MS), which was the first time that in vivo sampling method was adapted in detecting the anesthetic residue in the living aquatic product. The analytical performance of the developed method was evaluated in homogenized tilapia dorsal muscle, and the results demonstrated that the present method possessed low detection limits 1...
June 1, 2017: Talanta
John C Beaulieu, Javier M Obando-Ulloa
Pilot plant ultrafiltration was used to mimic the dominant U.S. commercial pomegranate juice extraction method (hydraulic pressing whole fruit), to deliver a not-from-concentrate (NFC) juice that was high-temperature short-time pasteurized and stored at 4 and 25°C. Recovered were 46 compounds, of which 38 were routinely isolated and subjected to analysis of variance to assess these NFC juices. Herein, 18 of the 21 consensus pomegranate compounds were recovered. Ultrafiltration resulted in significant decreases for many compounds...
August 15, 2017: Food Chemistry
Jihéne Bouhlel, Jérémy Ratel, Said Abouelkaram, Frédéric Mercier, Angelique Travel, Elisabeth Baéza, Catherine Jondreville, Gaud Dervilly-Pinel, Philippe Marchand, Bruno Le Bizec, Estelle Dubreil, Sophie Mompelat, Eric Verdon, Chanthadary Inthavong, Thierry Guérin, Douglas N Rutledge, Erwan Engel
Starting from a critical analysis of a first "proof of concept" study on the utility of the liver volatolome for detecting livestock exposure to environmental micropollutants (Berge et al., 2011), the primary aim of this paper is to improve extraction conditions so as to obtain more representative extracts by using an extraction temperature closer to livestock physiological conditions while minimizing analytical variability and maximizing Volatile Organic Compound (VOC) abundancies. Levers related to extraction conditions and sample preparation were assessed in the light of both abundance and coefficient of variation of 22 candidate VOC markers identified in earlier volatolomic studies...
March 7, 2017: Journal of Chromatography. A
Yan Lu, Wenqi Niu, Xue Zou, Chengyin Shen, Lei Xia, Chaoqun Huang, Hongzhi Wang, Haihe Jiang, Yannan Chu
Breath analysis is a non-invasive approach which may be applied to disease diagnosis and pharmacokinetic study. In the case of offline analysis, the exhaled gas needs to be collected and the sampling bag is often used as the storage vessel. However, the sampling bag usually releases some extra compounds, which may interfere with the result of the breath test. In this study, a novel breath sampling glass bottle was developed with a syringe needle sampling port for solid phase microextraction (SPME). Such a glass bottle scarcely liberates compounds and can be used to collect exhaled gas for ensuing analysis by gas chromatography-mass spectrometry (GC-MS)...
March 23, 2017: Journal of Chromatography. A
Celine Liaud, Jean-Jacques Schwartz, Maurice Millet
XAD-2® passive samplers (PAS) have been exposed simultaneously for 14 days on two sites, one rural and one urban, situated in Alsace (East of France) during intensive pesticides application in agriculture (between March and September). PAS have been extracted and analyzed for current-used pesticides and lindane with an analytical method coupling accelerated solvent extraction (ASE), solid-phase microextraction (SPME) and GC/MS/MS. Results show the detection of pesticides is linked to the period of application and spatial and temporal variabilities can be observed with these PAS during the selected sampling period...
March 29, 2017: Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes
Mohammad Saraji, Mohammad Taghi Jafari, Mehdi Mossaddegh
Halloysite nanotubes were modified in three simple steps including etching, hydroxylation and amino grafting. The sol-gel technique was used for the chemical bonding of the modified halloysite nanotubes (MHNTs) to fused-silica support. The MHNTs, as a novel adsorbent was applied as a SPME coating. Diazinon, parathion and fenthion were selected as the model compounds to study the extraction efficiency of the coating. Gas chromatography-corona discharge ion mobility spectrometry was applied for the analysis of the extracted analytes...
April 29, 2017: Analytica Chimica Acta
Cláudia M Dias, Helvécio C Menezes, Zenilda L Cardeal
This paper shows the use of exhaled air as a biomonitoring method to assess perchloroethylene (PERC) environmental and occupational exposure. A sensitive, fast, and solvent free analytical method was developed to determine PERC in ambient and exhaled air of individuals occupationally exposed. The developed method used cold fiber solid phase microextraction (CF-SPME) as the sampling technique, and a standard permeation method to simulation of air matrix. The analysis were conducted by gas chromatography coupled to mass spectrometry (GC/MS)...
March 22, 2017: Environmental Research
Selenia De Grazia, Emanuela Gionfriddo, Janusz Pawliszyn
The current work presents the optimization of a protocol enabling direct extraction of avocado samples by a new Solid Phase Microextraction matrix compatible coating. In order to further extend the coating life time, pre-desorption and post-desorption washing steps were optimized for solvent type, time, and degree of agitation employed. Using optimized conditions, lifetime profiles of the coating related to extraction of a group of analytes bearing different physical-chemical properties were obtained. Over 80 successive extractions were carried out to establish coating efficiency using PDMS/DVB 65µm commercial coating in comparison with the PDMS/DVB/PDMS...
May 15, 2017: Talanta
JingHong Li, Hui Xu
Exploration of volatile organic compounds (VOCs) generated by lung cell lines is a powerful and non-invasive tool for the detection of potential volatile biomarkers of lung cancer. In this study, a simple and sensitive solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) method was developed for the determination of VOCs in the headspace gas of lung cell lines. For the purpose of preconcentration, a novel polyaniline/polypyrrole/graphene oxide (PANI/PPy/GO) coating was prepared on the surface of stainless steel fiber via in-situ electrochemical deposition for the first time...
May 15, 2017: Talanta
Mingguang Ma, Huiju Wang, Qi Zhen, Min Zhang, Xinzhen Du
A novel solid-phase microextraction (SPME) fiber was fabricated by direct electrodeposition of polyaniline (PANI) coated the titania nanotube arrays in situ grown on the titanium wire followed by carbonization at 500°C under nitrogen atmosphere. The resulting titanium-based fiber with nitrogen-enriched carbonaceous material coated titania nanotubes (N-C/TiO2NTs/Ti) showed better extraction performance for ultraviolet (UV) filters among model aromatic compounds compared with common PANI as well as commercial polydimethylsiloxane and polyacrylate coatings...
May 15, 2017: Talanta
Mariane A Andrade, Fernando M Lanças
Ochratoxin A (OTA), a widely studied mycotoxin, can be found in a variety of food matrices. As its concentration in food is generally low (in the order of μg kg(-1)), sample preparation techniques are necessary for the analyte purification and pre-concentration in order to achieve the required low detection limits. The separation and detection methods used for OTA analysis should also offer proper sensitivity in order to allow the adequate quantification of the analyte. This manuscript addresses the development of a methodology aiming the analysis of OTA in wine samples by packed in-tube SPME in flow through extraction mode coupled to HPLC-MS/MS...
April 14, 2017: Journal of Chromatography. A
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