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https://www.readbyqxmd.com/read/27892815/monitoring-trihalomethanes-and-nitrogenous-disinfection-by-products-in-blending-desalinated-waters-using-solid%C3%A2-phase-microextraction-and-gas-chromatography
#1
Providencia González-Hernández, Manuel Hernández-Padrón, Verónica Pino, Ana M Afonso, Juan H Ayala
A simple and efficient method has been developed for the extraction and determination of sixteen common volatile halogenated disinfection by-products (DBPs) in blending desalinated waters, using headspace solid-phase microextraction and gas chromatography with flame-ionization detection (HS-SPME/GC-FID). The DBPs determined included 4 trihalomethanes, 6 haloacetonitriles and 6 halonitromethanes. After the optimization using factorial designs of the HS-SPME parameters (optimum: carboxen/polydimethylsiloxane (CAR/PDMS) fiber, extraction time of 60 min at 30 °C, pH 7, addition of 40% (w/v) of sodium chloride, and desorption time of 2 min at 250 °C), quantification limits ranged from 3...
November 28, 2016: Environmental Technology
https://www.readbyqxmd.com/read/27887699/an-improved-method-for-the-analysis-of-2-aminoacetophenone-in-wine-based-on-headspace-solid-phase-microextraction-and-heart-cut-multidimensional-gas-chromatography-with-selective-detection-by-tandem-mass-spectrometry
#2
Hans-Georg Schmarr, Jutta Keiser, Susann Krautwald
Heart-cut multidimensional gas chromatography coupled to selective mass spectrometric detection (H/C MDGC-MS-MS) was shown to be a suitable combination for analysis of the key component for the wine off-flavor named "atypical aging off-flavor" (german: "Untypische Alterungsnote", UTA), 2-aminoacetophenone (2-AAP). Headspace solid phase microextraction (HS-SPME) was applied as an easy to automate sample preparation step suiting routine control situations. During method development two critical aspects were found, of which one is the chemical degradation of the neat substance, leading to signal reduction and a false response behavior...
November 20, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27869784/phytochemical-profiling-of-flavonoids-phenolic-acids-terpenoids-and-volatile-fraction-of-a-rosemary-rosmarinus-officinalis-l-extract
#3
Pedro Mena, Martina Cirlini, Michele Tassotti, Kelli A Herrlinger, Chiara Dall'Asta, Daniele Del Rio
This paper presents a comprehensive analysis of the phytochemical profile of a proprietary rosemary (Rosmarinus officinalis L.) extract rich in carnosic acid. A characterization of the (poly)phenolic and volatile fractions of the extract was carried out using mass spectrometric techniques. The (poly)phenolic composition was assessed by ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS(n)) and a total of 57 compounds were tentatively identified and quantified, 14 of these being detected in rosemary extract for the first time...
November 19, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27866847/detection-of-trans-fatty-acids-by-high-performance-liquid-chromatography-coupled-with-in-tube-solid-phase-microextraction-using-hydrophobic-polymeric-monolith
#4
Fangling Wu, Jiabin Wang, Qi Zhao, Nan Jiang, Xucong Lin, Zenghong Xie, Jianhua Li, Qiqing Zhang
Based on in-tube solid-phase microextraction (in-tube SPME) using a hydrophobic poly (octadecyl methacrylate-co-ethylene dimethacrylate) [poly (OMA-co-EDMA)] monolith, a simple high performance liquid chromatography (HPLC) method has been developed for detection of trans-fatty acids (TFAs) as their fatty acid methyl esters (FAMEs). The poly (OMA-co-EDMA) monolithic column with high hydrophobicity was specially prepared for simultaneous microextraction, pre-separation and purification for the analytes. The pre-separation selectivity, the extraction efficiency, and the purification effect for FAMEs were investigated respectively...
November 10, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/27863835/metabolites-profiling-reveals-for-antimicrobial-compositional-differences-and-action-mechanism-in-the-toothbrushing-stick-miswak-salvadora-persica
#5
Mohamed A Farag, Sherifa Fahmy, Mouchira A Choucry, Mariam O Wahdan, Mahmoud Fahmi Elsebai
Among many plant species suitable for preparing toothbrushing sticks, miswak (Salvadora persica, family Salvadoraceae) is found the most effective tool for oral hygiene. S. persica possesses antibacterial, antiviral and antifungal effects against oral microbes, mostly due to its benzyl isothiocyanate content. To provide insight into S. persica chemical composition, volatile constituents from roots and stems of S. persica grown in Egypt and Saudi Arabia were profiled using solid-phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS)...
January 30, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27862062/paper-based-solid-phase-microextraction-for-analysis-of-8-hydroxy-2-deoxyguanosine-in-urine-sample-by-ce-lif
#6
Xiangying Meng, Qinrui Liu, Yongsheng Ding
An easy-to-do paper-based solid phase microextraction (p-SPME) was developed for determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in urine sample by CE-LIF. Small piece of filter paper was used as a solid phase to extract 8-OHdG from urine sample. Its primary mechanism is based on the hydrogen-bonding interaction between 8-OHdG and cellulose molecules. The effects of the pH of the sample solution, extraction time and temperature on the peak area of the analyte were investigated in order to obtain the optimal p-SPME conditions...
November 9, 2016: Electrophoresis
https://www.readbyqxmd.com/read/27855921/determination-of-5-hydroxymethylfurfural-in-honey-using-headspace-solid-phase-microextraction-coupled-with-a-polyoxometalate-coated-piezoelectric-quartz-crystal
#7
Marta I S Veríssimo, José A F Gamelas, Dmitry V Evtuguin, M Teresa S R Gomes
High concentrations of 5-hydroxymethylfurfural (HMF) in honey provide an indication of overheating under inappropriate storage conditions or aging. Conventional methods for determining HMF are cumbersome and require expensive equipment or hazardous reagents. Hence the aim of this study was to propose a new analytical tool for HMF determination in honey, using a low cost acoustic wave sensor. Volatile organic compounds (VOCs) of honey samples were extracted, using the solid phase microextraction (SPME) technique, and HMF was quantified, using a piezoelectric quartz crystal with gold electrodes coated with a layer of decamolybdodivanado phosphoric acid, sensitive to HMF...
April 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27855884/determination-of-semi-volatile-additives-in-wines-using-spme-and-gc-ms
#8
Gulyaim N Sagandykova, Mereke B Alimzhanova, Yenglik T Nurzhanova, Bulat Kenessov
Parameters of headspace solid-phase microextraction, such as fiber coating (85μm CAR/PDMS), extraction time (2min for white and 3min for red wines), temperature (85°C), pre-incubation time (15min) were optimized for identification and quantification of semi-volatile additives (propylene glycol, sorbic and benzoic acids) in wines. To overcome problems in their determination, an evaporation of the wine matrix was performed. Using the optimized method, screening of 25 wine samples was performed, and the presence of propylene glycol, sorbic and benzoic acids was found in 22, 20 and 6 samples, respectively...
April 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27855313/characterization-of-the-clostridium-difficile-volatile-metabolome-using-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#9
Christiaan A Rees, Aimee Shen, Jane E Hill
Clostridium difficile is a bacterial pathogen capable of causing life-threatening infections of the gastrointestinal tract characterized by severe diarrhea. Exposure to certain classes of antibiotics, advanced age, and prolonged hospitalizations are known risk factors for infection by this organism. Anecdotally, healthcare providers have reported that they can smell C. difficile infections in their patients, and several studies have suggested that there may indeed be an olfactory signal associated with C. difficile-associated diarrhea...
November 9, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/27847109/modified-zeolitic-imidazolate-framework-8-as-solid-phase-microextraction-arrow-coating-for-sampling-of-amines-in-wastewater-and-food-samples-followed-by-gas-chromatography-mass-spectrometry
#10
Hangzhen Lan, Tuukka Rönkkö, Jevgeni Parshintsev, Kari Hartonen, Ning Gan, Motolani Sakeye, Jawad Sarfraz, Marja-Liisa Riekkola
In this study, a novel solid phase microextration (SPME) Arrow was prepared for the sampling of volatile low molecular weight alkylamines (trimethylamine (TMA) and triethylamine (TEA)) in wastewater, salmon and mushroom samples before gas chromatographic separation with mass spectrometer as detector. Acidified zeolitic imidazolate framework-8 (A-ZIF-8) was utilized as adsorbent and poly(vinyl chloride) (PVC) as the adhesive. The custom SPME Arrow was fabricated via a physical adhesion: (1) ZIF-8 particles were suspended in a mixture of tetrahydrofuran (THF) and PVC to form a homogeneous suspension, (2) a non-coated stainless steel SPME Arrow was dipped in the ZIF-8/PVC suspension for several times to obtain a uniform and thick coating, (3) the pore size of ZIF-8 was modified by headspace exposure to hydrochloric acid in order to increase the extraction efficiency for amines...
November 4, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27836229/hollow-fiber-stir-bar-sorptive-extraction-and-microwave-assisted-derivatization-of-amino-acids-in-biological-matrices
#11
Jia Li, Huan-Yang Qi, Yan-Bin Wang, Qiong Su, Shang Wu, Lan Wu
A kind of solid phase microextraction configuration combining the principles of hollow fiber solid phase microextraction (HF-SPME) and stir bar sorptive extraction (SBSE) is presented. The main feature of HF-SBSE is the use of microporous hollow fiber acting as the carrier and filter, while a thin stainless steel wire and silica microspheres in the lumen of hollow fiber respectively acting as the magnetic stirrer and the dispersed sorbents for the collection and extraction of the target analytes, thus affording extraction process like SBSE...
November 1, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27836227/polythiophene-graphene-oxide-nanostructured-electrodeposited-coating-for-on-line-electrochemically-controlled-in-tube-solid-phase-microextraction
#12
Maryam Shamsayei, Yadollah Yamini, Hamid Asiabi
In this work, a novel polythiophene/graphene oxide (PTh/GO) nanostructured coating was introduced for on-line electrochemically-controlled in-tube solid phase microextraction of amitriptyline (AMI) and doxepin (DOX) as antidepressant drugs. The PTh/GO coating was prepared on the inner surface of a stainless steel tube by a facile in-situ electro-deposition method and it was used as a working electrode for electrochemically control in-tube solid phase microextraction. In the PTh/GO coating, GO acts as an anion dopant and sorbent...
December 2, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27833635/gene-metabolite-networks-of-volatile-metabolism-in-airen-and-tempranillo-grape-cultivars-revealed-a-distinct-mechanism-of-aroma-bouquet-production
#13
José L Rambla, Almudena Trapero-Mozos, Gianfranco Diretto, Angela Rubio-Moraga, Antonio Granell, Lourdes Gómez-Gómez, Oussama Ahrazem
Volatile compounds are the major determinants of aroma and flavor in both grapes and wine. In this study, we investigated the emission of volatile and non-volatile compounds during berry maturation in two grape varieties (Airén and Tempranillo) throughout 2010 and 2011. HS-SPME coupled to gas chromatography and mass spectrometry was applied for the identification and relative quantitation of these compounds. Principal component analysis was performed to search for variability between the two cultivars and evolution during 10 developmental stages...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27829300/evaluation-of-the-volatile-profile-of-tuber-liyuanum-by-hs-spme-with-gc-ms
#14
Changjiao Liu, Yu Li
The volatile components of Tuber liyuanum were determined by HS-SPME with GC-MS for the first time. The effects of different fibre coating, extraction time, extraction temperature and sample amount were studied to get optimal extraction conditions. The optimal conditions were SPME fibre of Carboxen/PDMS, extraction time of 40 min, extraction temperature of 80 °C, sample amount of 2 g. Under these conditions 57 compounds in volatile of T. liyuanum were detected with a resemblance percentage above 80%. Aldehydes and aromatics were the main chemical families identified...
November 10, 2016: Natural Product Research
https://www.readbyqxmd.com/read/27826631/determination-of-volatile-organic-compounds-including-alcohols-in-refill-fluids-and-cartridges-of-electronic-cigarettes-by-headspace-solid-phase-micro-extraction-and-gas-chromatography-mass-spectrometry
#15
Hyun-Hee Lim, Ho-Sang Shin
An analytical method for the detection of 14 volatile organic compounds (VOCs) was developed to investigate VOCs in refill fluids and cartridges of electronic cigarettes (EC) using headspace solid-phase micro extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). In total, 14 VOCs were identified and quantified in 283 flavored liquids, 21 nicotine liquids, and 12 disposable cartridges. The detected concentration ranges of the VOCs are as follows: benzene (0.008-2.28 mg L(-1)), toluene (0...
November 9, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27826436/the-flavor-and-nutritional-characteristic-of-four-strawberry-varieties-cultured-in-soilless-system
#16
Li Liu, Mei-Ling Ji, Min Chen, Ming-Yue Sun, Xi-Ling Fu, Ling Li, Dong-Sheng Gao, Cui-Ying Zhu
Strawberry fruits (cv. Benihoppe, Tochiotome, Sachinoka, and Guimeiren) were harvested and evaluated the flavor and nutritional parameters. By principal component analysis and hierarchical clustering analysis, differences were observed based on the volatile compounds composition, sugar and acid concentration, sweetness, and total soluble sugars/total organic acids of the four varieties. A total of 37, 48, 65, and 74 volatile compounds were identified and determined in cv. Benihoppe, Tochiotome, Sachinoka, and Guimeiren strawberry fruits extracted by head-space solid-phase microextraction (HS-SPME), respectively...
November 2016: Food Science & Nutrition
https://www.readbyqxmd.com/read/27821850/a-comparative-metabolomics-approach-reveals-early-biomarkers-for-metabolic-response-to-acute-myocardial-infarction
#17
Sara E Ali, Mohamed A Farag, Paul Holvoet, Rasha S Hanafi, Mohamed Z Gad
Discovery of novel biomarkers is critical for early diagnosis of acute coronary syndrome (ACS). Serum metabolite profiling of ST-elevation myocardial infarction (STEMI), unstable angina (UA) and healthy controls was performed using gas chromatography mass spectrometry (GC/MS), solid-phase microextraction coupled to gas chromatography mass spectrometry (SPME-GC/MS) and nuclear magnetic resonance ((1)H-NMR). Multivariate data analysis revealed a metabolic signature that could robustly discriminate STEMI patients from both healthy controls and UA patients...
November 8, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27816883/electrochemical-luminescence-determination-of-hyperin-using-a-sol-gel-graphene-luminescent-composite-film-modified-electrode-for-solid-phase-microextraction
#18
Xiaojun Zou, Fang Shang, Sui Wang
In this paper, a novel electrochemiluminescence (ECL) sensor of sol-gel@graphene luminescent composite film modified electrode for hyperin determination was prepared using graphene (G) as solid-phase microextraction (SPME) material, based on selective preconcentration of target onto an electrode and followed by luminol ECL detection. Hyperin was firstly extracted from aqueous solution through the modified GCE. Hydrogel, electrogenerated chemiluminescence reagents, pH of working solution, extraction time and temperature and scan rate were discussed...
October 23, 2016: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/27807849/evaluation-of-cross-contamination-of-nylon-bags-with-heavy-loaded-gasoline-fire-debris-and-with-automotive-paint-thinner
#19
Filipa Belchior, Stephen P Andrews
Nylon bags are used for packaging fire debris in several countries, particularly in Europe. The possibility of cross-contamination during transport from the fire scene to the laboratory, in normal casework conditions in the U.K., was studied for two brands of nylon bags, using simulated heavy-loaded fire debris. Three experiments were carried out with each brand, using as sample a piece of cotton fabric soaked with gasoline. One experiment was carried out using automotive paint thinner (oxygenated solvent)...
November 2016: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/27787985/sensitive-monitoring-of-fluoroquinolones-in-milk-and-honey-using-multiple-monolithic-fiber-solid-phase-microextraction-coupled-to-liquid-chromatography-tandem-mass-spectrometry
#20
Lei Chen, Xiaojia Huang
In present study, a new multiple monolithic fiber solid-phase microextraction (MMF-SPME) based on poly (apronal-co-divinylbenzene/ ethylenedimethacrylate) monolith (APDE) was synthesized. The effect of preparation parameters of APED on extraction efficiency was studied thoroughly. The combination of APDE/MMF-SPME with high-performance liquid chromatography tandem mass spectrometry detection (HPLC/MS-MS) was developed for sensitive monitoring of ultra-trace fluoroquinolones (FQs) in foodstuffs including milk and honey samples...
October 27, 2016: Journal of Agricultural and Food Chemistry
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