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William P McMahon, Arjuna Subramanian, Carina S Minardi, Rohan Dalvi, Kaveh Jorabchi
Ion mobility-mass spectrometry (IM-MS) has gained considerable attention for detection of clusters and weakly-bound species created by electrospray ionization (ESI). Atmospheric-pressure (AP) IM-MS offers an advantage in these studies compared to its low-pressure counterpart, owing to soft introduction of ions into the mobility cell with minimal ion activation. Here, we report new approaches to improve the sensitivity and soft ion introduction in AP-IM-MS. For the former, we demonstrate enhanced aerodynamic sampling of ions from the mobility cell into the MS using pulsed-field sampling...
October 26, 2016: Analytical Chemistry
Maurizio Baldassarre, Marco Domenicali, Marina Naldi, Maristella Laggetta, Ferdinando A Giannone, Maurizio Biselli, Daniela Patrono, Carlo Bertucci, Mauro Bernardi, Paolo Caraceni
Decompensated cirrhosis is associated to extensive post-transcriptional changes of human albumin (HA). This study aims to characterize the occurrence of HA homodimerization in a large cohort of patients with decompensated cirrhosis and to evaluate its association with clinical features and prognosis. HA monomeric and dimeric isoforms were identified in peripheral blood by using a HPLC-ESI-MS technique in 123 cirrhotic patients hospitalized for acute decompensation and 50 age- and sex-comparable healthy controls...
October 26, 2016: Scientific Reports
Giuseppe Mannino, Andrea Occhipinti, Massimo E Maffei
Boswellia serrata and Boswellia sacra (syn. B. carteri) are important medicinal plants widely used for their content of bioactive lipophilic triterpenes. The qualitative and quantitative determination of boswellic acids (BAs) is important for their use in dietary supplements aimed to provide a support for osteoarthritic and inflammatory diseases. We used High Performance Liquid Chromatography (HPLC)-Diode Array Detector (DAD) coupled to ElectroSpray Ionization and tandem Mass Spectrometry (ESI-MS/MS) for the qualitative and quantitative determination of BAs extracted from the gum resins of B...
October 6, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Elixabet Díaz-de-Cerio, Federica Pasini, Vito Verardo, Alberto Fernández-Gutiérrez, Antonio Segura-Carretero, Maria Fiorenza Caboni
Due to the importance of the proanthocyanidins (PAs) bioactivity and its relationship with the PAs degree of polymerization (DP), an experimental design was carried out to establish the best extraction conditions in order to evaluate the proanthocyanidins content and their degree of polymerization in Psidium guajava leaves at different oxidation state. Optimal conditions achieved by response surface methodology were 50% acetone/water (v/v), 48°C, 30min, and 0% acetic acid (v/v). The highest DP has been found in the low oxidized state (DP 13 plus the polymers)...
October 13, 2016: Journal of Pharmaceutical and Biomedical Analysis
Sai Zheng, Jia-Chen Shi, Jian-Ying Hu, Wen-Xin Hu, Jing Zhang, Bing Shao
The reaction kinetics and transformation pathways between bisphenol F (BPF) and sodium hypochlorite were investigated at pH values ranging from 6.5 to 8.5 and with different initial concentration ratios. The reaction rate was pH- and free available chlorine (FAC)-dependent: the reaction rate at pH 8.5 was almost 10 times than that at pH 6.5. A total of 40 compounds were tentatively identified as chloro-substituted BPF and polyphenolic compounds by liquid chromatography quadrupole time-of-flight mass spectrometry operating in electrospray ionization mode (LC-ESI-Q-ToF), and 4 main byproducts were confirmed by (1)H and (13)C nuclear magnetic resonance (NMR)...
October 19, 2016: Water Research
Tomasz Mroczek, Tomasz Plech, Monika Wujec
Till now, three major spectroscopic techniques, fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, have been used for determination of thiol-thione tautomeric forms. Therefore, a novel analytical concept of discrimination of 1,2,4-triazole-3-thione and 3-thiol tautomers using two high-resolution mass spectrometers has been proposed. It comprises the high-performance liquid chromatography (HPLC) hyphenated with electrospray ionization (ESI)-time-of-flight mass spectrometry (ESI-TOF-MS, positive ion mode) followed by in-source collision-induced dissociation (CID) and low-energy CID-tandem mass spectrometry (MS/MS) analysis measured with a Quadruple-TOF-MS instrument...
October 24, 2016: Journal of Chromatographic Science
Marlies Decleer, Andreja Rajkovic, Benedikt Sas, Annemieke Madder, Sarah De Saeger
Rapid and accurate UPLC-MS/MS methods for the simultaneous determination of beauvericin and the related enniatins (A, A1, B, B1), together with cereulide were successfully developed and validated in cereal and cereal-based food matrices such as wheat, maize, rice and pasta. Although these emerging foodborne toxins are of different microbial origin, the similar structural, toxicological and food safety features provided rationale for their concurrent detection in relevant food matrices. A Waters Acquity UPLC system coupled to a Waters Quattro Premier XE™ Mass Spectrometer operating in ESI+ mode was employed...
October 4, 2016: Journal of Chromatography. A
Vagner Bezerra Dos Santos, Daniela Daniel, Melina Singh, Claudimir Lucio do Lago
A capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) method for amphetamine (AM), phentermine (PTM), methamphetamine (MAM), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), and methylenedioxyethylamphetamine (MDEA) in commercial samples of homeopathic and phytotherapic medicines and dietary supplements is presented. The samples were submitted to a modified QuEChERS extraction procedure (at apparent pH 13) followed by electrophoretic separation in 0.1molL(-1) formic acid electrolyte (pH 2...
October 17, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Ben Ajmia Wafa, Mohamed Makni, Sonda Ammar, Lamia Khannous, Amal Ben Hassana, Mohamed Bouaziz, Nour Eddine Es-Safi, Radhouane Gdoura
Punica granatum L. is widely recognized for its potency against a broad spectrum of bacterial pathogens. The purpose of this study was to explore the inhibitory and the bactericidal activities of Punica granatum against Salmonella strains. The effect of extracts obtained from different parts (peels, seeds, juice and flowers) of pomegranate and using different solvents against Salmonella enterica serovars Kentucky and Enteritidis isolated from chicken meat was thus investigated. Salmonella strains were identified with the standard API-20E system and confirmed by real time PCR...
October 11, 2016: International Journal of Food Microbiology
Ana Coito, Christoph M Michel, Pieter van Mierlo, Serge Vulliemoz, Gijs Plomp
: The importance of functional brain connectivity to study physiological and pathological brain activity has been widely recognized. Here, we aimed to 1) review a methodological pipeline to investigate directed functional connectivity between brain regions using source signals derived from high-density EEG; 2) elaborate on some methodological challenges; 3) apply this pipeline to temporal lobe epilepsy (TLE) patients and healthy controls to investigate directed functional connectivity differences in the theta and beta frequency bands during EEG epochs without visible pathological activity...
October 20, 2016: IEEE Transactions on Bio-medical Engineering
Imelda Ryona, Jack Henion
Despite many benefits including simple point-of-care sample collection, reduced costs, and simplified shipping and storage, dried blood spot (DBS) techniques have faced adoption resistance such as the hematocrit (Hct) effects and the established preference for bioanalysis of plasma rather than whole blood. One way to potentially circumvent these challenges is to adopt the concept of a dried plasma spot (DPS) technique. One approach to accomplishing this is through an on-card red blood cell (RBC) filtration to generate plasma from whole blood without the need for centrifugation...
October 24, 2016: Analytical Chemistry
Akio Hayashi, Hiromi Ota, Xavier López, Norihito Hiyoshi, Nao Tsunoji, Tsuneji Sano, Masahiro Sadakane
Dipotassium cation (K(+))-encapsulated Preyssler-type phosphotungstate, [P5W30O110K2](13-), was prepared by heating monobismuth (Bi(3+))-encapsulated Preyssler-type phosphotungstate, [P5W30O110Bi(H2O)](12-), in acetate buffer in the presence of an excess amount of potassium cations. Characterization of the isolated potassium salt, K13[P5W30O110K2] (1a), and its acid form, H13[P5W30O110K2] (1b), by single crystal X-ray structure analysis, (31)P and (183)W nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, cyclic voltammetry (CV), high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), and elemental analysis revealed that two potassium cations are encapsulated in the Preyssler-type phosphotungstate molecule with formal D5h symmetry, which is the first example of a Preyssler-type compound with two encapsulated cations...
October 24, 2016: Inorganic Chemistry
Omer Yehezkeli, Nicholas M Bedford, Eunsol Park, Ke Ma, Jennifer N Cha
There has been active interest to identify new methods to reduce CO2 into usable fuel sources. In this work, we demonstrate two types of photo-electrochemical cells (PECs) that photoreduce CO2 directly to formate in aqueous solutions both in the presence and absence of external bias or additional electron sources. The photocathodes were either a CuFeO2 /CuO electrode or a bilayer of CdTe on NiO, whereas the photoanode was a bilayer of NiOx on CdS. The PECs were characterized by using both electrochemistry and spectroscopy, and the products formed from CO2 reduction were characterized and quantified by using (1) H NMR spectroscopy and ESI-MS...
October 24, 2016: ChemSusChem
Taewoong Rho, Mila Jung, Min Won Lee, Young-Won Chin, Kee Dong Yoon
Efficient high-performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n-Butanol soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid (1), swertiamarin (2) and gentiopicroside (3), and a chromene derivative, macrophylloside D (4) which were successfully isolated by flow rate gradient (1.5 mL/min in 0-60 min, 5.0 mL/min in 60-120 min), and consecutive flow rate gradient HPCCC using n-butanol/0...
October 24, 2016: Journal of Separation Science
Yi Yong, Ammar Saleem, José A Guerrero-Analco, Pierre S Haddad, Alain Cuerrier, John T Arnason, Cory S Harris, Tim Johns
ETHNOPHARMACOLOGICAL RELEVANCE: Larix laricina, a native tree of North America, is a highly respected medicinal plant used for generations by Indigenous Peoples across its range, including the Cree of northern Québec who use the bark to treat symptoms of diabetes. This study investigates the antioxidant capacity and bioavailability of active constituents identified in L. laricina bark extracts. MATERIALS AND METHODS: (1) Oxygen radical absorbance capacity (ORAC) assay was employed to test antioxidant capacity of organic extracts (80% ethanol) from bark of L...
October 20, 2016: Journal of Ethnopharmacology
Song Klapoetke, Michael Hongwei Xie
Protein-level partial reduction was investigated as a novel sample preparation technique to characterize proteins with cystine knots or complex disulfide linkages. Human Factor Xa containing twelve disulfide bonds was selected as a model protein to demonstrate this methodology. Five in twelve disulfide linkages were characterized through conventional non-reduced samples while the other seven disulfide linkages containing cystine knots were successfully characterized though partially reduced samples. Each disulfide linkage was confirmed through product ions generated by an UPLC-ESI QTOF MS system equipped with data independent collision-induced dissociation (CID) acquisition...
October 5, 2016: Journal of Pharmaceutical and Biomedical Analysis
Minjie Zhao, Michel Mozeika Arau Jo, Stéphanie Dal, Séverine Sigrist, Martine Bergaentzlé, David Ramanitrahasimbola, Charles Andrianjara, Eric Marchioni
This study describes a selective and effective pressurized liquid extraction (PLE) coupled with HPLC-DAD-ESI/MS method for the identification and quantification of three fructosazine analogues (FZAs), fructosazine, 2,6- and 2,5-deoxyfructosazine in Madeglucyl(®) (MG) which is an ammonia treated extract of Eugenia jambolana Lamarck seeds, and is the world's first anti-diabetic phytodrug. FZAs were extracted from MG by PLE using methanol as extraction solvent. The PLE extract was then analyzed directly by HPLC-DAD-ESI/MS without cleanup step...
October 13, 2016: Journal of Chromatography. A
Canlan Jiang, Yuefei Ji, Yuanyuan Shi, Jifei Chen, Tianming Cai
Widespread occurrence of fluoroquinolone antibiotics (FQs) in surface water, groundwater, soil and sediment has been reported and their remediation is essentially needed. Sulfate radical (SO4(-)) based advanced oxidation processes (SR-AOPs) are promising technologies for soil and groundwater remediation. In this study, the degradation kinetics, mechanisms, and effects of natural water matrices on heat-activated persulfate (PS) oxidation of FQs were systematically investigated. Experimental results clearly demonstrated that 92% of CIP was removed within 180 min (pH = 7, 60 °C)...
October 12, 2016: Water Research
Ilaria Degano, Jacopo La Nasa, Elisa Ghelardi, Francesca Modugno, Maria Perla Colombini
Lipid binders have traditionally been determined in paintings by using gas chromatography/mass spectrometry (GC/MS) to identify the characteristic profiles and ratios of fatty acids . However, the presence of mixtures in contemporary and modern oil paints makes the GC/MS determination of fatty acids insufficient to fully characterize the lipid binding media. In this study we prove that triacylglycerol (TAG) profiling by high-performance liquid chromatography with high-resolution tandem mass spectrometry, using ESI in positive and negative ionization modes is highly effective...
December 1, 2016: Talanta
Shima N N S Hashim, Lachlan J Schwarz, Basil Danylec, Mahesh K Potdar, Reinhard I Boysen, Milton T W Hearn
This investigation describes a general procedure for the selectivity mapping of molecularly imprinted polymers, using (E)-resveratrol-imprinted polymers as the exemplar, and polyphenolic compounds present in Pinot noir grape skin extracts as the test compounds. The procedure is based on the analysis of samples generated before and after solid-phase extraction of (E)-resveratrol and other polyphenols contained within the Pinot noir grape skins using (E)-resveratrol-imprinted polymers. Capillary reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionisation tandem mass spectrometry (ESI MS/MS) was then employed for compound analysis and identification...
December 1, 2016: Talanta
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