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Journal of Mass Spectrometry: JMS

Simone Cristoni, Guglielmo Dusi, Paolo Brambilla, Adriana Albini, Matteo Conti, Maura Brambilla, Antonino Bruno, Francesca Digaudio, Luca Ferlin, Valeria Tazzari, Silvia Mengozzi, Simone Barera, Carlos Salier, Tommaso Trenti, Marco Cantu, Luigi Rossi Bernardi, Douglas M Noonan
Electrospray Ionization (EI) and Collision Induced Dissociation tandem mass spectrometry (CID-MS/MS) are usually employed to obtain compound identification through a mass spectra match. Different algorithms have been developed for this purpose (for example the NIST match algorithm). These approaches compare the tandem mass spectra (MS/MS) of the unknown analyte with the MS/MS spectra of known compounds inserted in a database. The compounds are usually identified on the basis of spectral match value associated with a probability of recognition...
October 24, 2016: Journal of Mass Spectrometry: JMS
Qiang Zhao, Jianli Liu, Bo Wang, Xiaohua Zhang, Guangyan Huang, Wei Xu
Rapid, direct and trace detection of explosives in an open environment is of particular need in homeland and/or transportation security. In this work, an aerodynamic assisted thermo desorption mass spectrometry method was developed for the direct quantitative analyses of explosives from a distance. Remote non-volatile explosive sensing was achieved for 2, 4, 6-trinitrotoluene (TNT), trinitrohexahydro-1, 3, 5-triazine (RDX), 8701 (main ingredient: RDX 98.5%) and C4 (a type of plastic explosive) with a distance of 0...
October 13, 2016: Journal of Mass Spectrometry: JMS
Bi-Cheng Yang, Feng Wang, Xiao Yang, Wei Zou, Jia-Chun Wang, Yang Zou, Fa-Ying Liu, Huai Liu, Ou-Ping Huang
Newborn screening is one of public health concerns designed to screen infants shortly after birth. Prenatal exposure to tobacco smoke such as nicotine has been reported to effects on babies. Levels of nicotine and cotinine in meconium were widely used to evaluate the tobacco exposure of fetuses during pregnancy in a polluted environment. In this study, medical swabs were applied to collect meconium from newborn infants for detection of nicotine and cotinine by touch spray-mass spectrometry (TS-MS). Parameters such as choice of spray solvents, solvent volume and collision energy for screening of nicotine and cotinine were optimized...
October 10, 2016: Journal of Mass Spectrometry: JMS
Joachim Vater, Stefanie Herfort, Joerg Doellinger, Max Weydmann, Kristin Dietel, Sebastian Faetke, Peter Lasch
Paenibacillus polymyxa are rhizobacteria with a high potential to produce natural compounds of biotechnological and medical interest. Main products of P. polymyxa are fusaricidins, a large family of antifungal lipopeptides with a 15-guanidino-3-hydroxypentadecanoic acid (GHPD) as fatty acid side chain. We use the P. polymyxa strain M-1 as a model organism for the exploration of the biosynthetic potential of these rhizobacteria. Using matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) about 40 new fusaricidins were detected which were fractionated by reversed-phase (rp) HPLC...
October 6, 2016: Journal of Mass Spectrometry: JMS
Christof Stönner, Bettina Derstroff, Thomas Klüpfel, John N Crowley, Horst Fischer, Jonathan Williams
We examine the potential for PTR-TOF-MS systems to quantitatively measure glyoxal in ambient air by characterizing the response of the instrument to a dilute glyoxal sample, calibrating the system as a function of humidity. The concentration of glyoxal in a sample air-stream was measured with an UV absorption spectrometer in parallel to a PTR-TOF-MS. This calibration demonstrated that the PTR-TOF-MS has a relatively low sensitivity to glyoxal particularly at high humidity. Extensive fragmentation of glyoxal to formaldehyde was observed...
October 6, 2016: Journal of Mass Spectrometry: JMS
Dilshadbek T Usmanov, Lee Chuin Chen, Kenzo Hiraoka, Hiroshi Wada, Hiroshi Nonami, Shinichi Yamabe
Experimental and theoretical studies on the oxidation of saturated hydrocarbons (n-hexane, cyclohexane, n-heptane, n-octane, and isooctane) and ethanol in 28 Torr O2 or air plasma generated by a hollow cathode discharge (HCD) ion source were made. Ions corresponding to [M + 15](+) and [M + 13](+) in addition to [M - H](+) and [M - 3H](+) were detected as major ions where M is the sample molecule. The ions [M + 15](+) and [M + 13](+) were assigned as oxidation products, [M - H + O](+) and [M - 3H + O](+) , respectively...
October 5, 2016: Journal of Mass Spectrometry: JMS
Jien-Lian Chen, Chuping Lee, I-Chung Lu, Chia-Lung Chien, Yuan-Tseh Lee, Wei-Ping Hu, Chi-Kung Ni
Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mainly generate protonated ions from peptides and proteins but sodiated (or potassiated) ions from carbohydrates. The ion intensities of sodiated (or potassiated) carbohydrates generated by ESI and MALDI are generally lower than those of protonated peptides and proteins. Ab initio calculations and transition state theory were used to investigate the reasons for the low detection sensitivity for underivatized carbohydrates...
September 27, 2016: Journal of Mass Spectrometry: JMS
Faizan Zubair, Paul E Laibinis, William G Swisher, Junhai Yang, Jeffrey M Spraggins, Jeremy L Norris, Richard M Caprioli
Prefabricated surfaces containing alpha-cyano-4-hydroxycinnamic acid (CHCA) and trypsin have been developed to facilitate enzymatic digestion of endogenous tissue proteins prior to MALDI imaging mass spectrometry (IMS). Tissue sections are placed onto slides that were previously coated with CHCA and trypsin. After incubation to promote enzymatic digestion, the tissue is analyzed by MALDI IMS to determine the spatial distribution of the tryptic fragments. The peptides detected in the MALDI IMS dataset were identified by LC-MS/MS...
September 27, 2016: Journal of Mass Spectrometry: JMS
Lei Deng, Ai-Min Shi, Hong-Zhi Liu, Naren Meruva, Li Liu, Hui Hu, Ying Yang, Chun Huang, Peng Li, Qiang Wang
Peanut stems and leaves have been used traditionally as both herbal medicines and special food in Asia. In this study, the main functional compounds of peanut stems and leaves extracts were identified using UPLC separation coupled to high resolution mass spectrometry (QTOF-MS), and a traditional medicine library. Three different extraction solvents (ethyl acetate, petroleum ether and n-butanol) were evaluated to prepare the extracts of peanut stems and leaves. A total of 283 chemical compounds were identified in peanut stems and leaves extracts, of which 207 compounds are tentatively new identifications in Genus Arachis...
September 23, 2016: Journal of Mass Spectrometry: JMS
Kyung Man Park, Jeong Hee Moon, Seong Hoon Lee, Myung Soo Kim
In profiling of a specimen by matrix-assisted laser desorption ionization (MALDI) using a solid matrix, the solvent of the matrix solution extracts an analyte(s). A quantitative profiling cannot be achieved if the solvent evaporates before the complete extraction of the analyte. The extraction can become more quantitative when a liquid matrix dissolved in a solvent is used, which remains a liquid even after the evaporation of the solvent. To check this, radii of an analyte circle (rA ), a matrix solution drop (rD ), and a liquid matrix (rM ) remaining after the solvent evaporation were controlled...
September 14, 2016: Journal of Mass Spectrometry: JMS
Maja Friščić, Franz Bucar, Kroata Hazler Pilepić
Plants produce a great number of metabolites with potentially useful biological activities. Species from the genus Globularia (Plantaginaceae) are known as sources of different phenolic and iridoid compounds. Globularia alypum L. is a medicinal plant used as a healing agent in many Mediterranean countries. Similarities in phytochemical composition are often observed for related species. For Globularia spp. such findings were mostly based on identification of several isolated compounds from distinct species...
September 13, 2016: Journal of Mass Spectrometry: JMS
Manale Noun, Elsa Van Elslande, David Touboul, Helen Glanville, Spike Bucklow, Philippe Walter, Alain Brunelle
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging using cluster primary ion beams is used for the identification of the pigments in the painting of Rebecca and Eliezer at the Well by Nicolas Poussin. The combination of the high mass resolution of the technique with a sub-micrometer spatial resolution offered by a delayed extraction of the secondary ions, together with the possibility to simultaneously identifying both minerals and organics, has proved to be the method of choice for the study of the stratigraphy of a paint cross-section...
September 12, 2016: Journal of Mass Spectrometry: JMS
Andreina Ricci, Federico Pepi, Paola Cimino, Anna Troiani, Stefania Garzoli, Chiara Salvitti, Brunella Di Rienzo, Vincenzo Barone
In order to investigate the gas-phase mechanisms of the acid catalyzed degradation of ascorbic acid (AA) to furan we undertook a mass spectrometric (ESI/TQ/MS) and theoretical investigation at the B3LYP/6-31 + G(d,p) level of theory. The gaseous reactant species, the protonated ascorbic acid, [C6 H8 O6 ]H(+) , were generated by electrospray ionization (ESI) of a 10(-3) M H2 O/CH3 OH (1:1) ascorbic acid solution. In order to structurally characterize the gaseous [C6 H8 O6 ]H(+) ionic reactants, we estimated the proton affinity and the gas-phase basicity of ascorbic acid by the extended Cooks's kinetic method and by computational methods at the B3LYP/6-31 + G(d,p) level of theory...
September 7, 2016: Journal of Mass Spectrometry: JMS
Stephanie M Wagoner, Manogna Deeconda, Kayleah L Cumpian, Rafael Ortiz, Swetha Chinthala, Laurence A Angel
Whether traveling wave ion mobility - mass spectrometry (IM-MS), B3LYP/LanL2DZ density functional theory, and ion size scaled Lennard-Jones (LJ) collision cross sections (CCS) from the B3LYP optimized structures could be used to determine the type of Zn(II) coordination by the oligopeptide acetyl-His1 -Cys2 -Gly3 -Pro4 -Tyr5 -His6 -Cys7 (amb5 ) was investigated. The IM-MS analyses of a pH titration of molar equivalents of Zn(II):amb5 showed that both negatively- and positively-charged complexes formed and coordination of Zn(II) increased as the His and Cys deprotonated near their pKa values...
September 4, 2016: Journal of Mass Spectrometry: JMS
Yunfeng Chai, Lu Wang, Lin Wang
In the literature, it is reported that the protonated ketotifen mainly undergoes C = C double bond cleavage in electrospray ionization tandem mass spectrometry (ESI-MS/MS), however, there is no explanation on the mechanism of this fragmentation reaction. Therefore, we carried out a combined experimental and theoretical study on this interesting fragmentation reaction. The fragmentation of protonated ketotifen (m/z 310) always generated a dominant fragment ion at m/z 96 in different electrospray ionization mass spectrometers (ion trap, triple quadrupole, and LTQ-orbitrap)...
September 3, 2016: Journal of Mass Spectrometry: JMS
Ádám Nagy, László Abrankó
Hydroxycinnamoylquinic acids (HCQAs) are a major class of phenolic plant secondary metabolites, belonging to the chlorogenic acid family. Various health-beneficial properties of HCQAs have been shown, which has drawn interest for HCQA profiling in plants of human consumption. However this task remains challenging, since several isomeric HCQAs can be present in the sample with identical molecular formulae and the limited availability of reference standards poses additional challenges to their identification...
September 3, 2016: Journal of Mass Spectrometry: JMS
Yohei Sakaguchi, Tomoya Kinumi, Akiko Takatsu
Stable isotope-coding coupled with mass spectrometry is a popular method for quantitative proteomics and peptide quantification. However, the efficiency of the derivatization reaction at a particular functional group, especially in complex structures, can affect accuracy. Here, we present a dual functional-group derivatization of bioactive peptides followed by micro liquid chromatography-tandem mass spectrometry (LC-MS/MS). By separating the sensitivity-enhancement and isotope-coding derivatization reactions, suitable chemistries can be chosen...
September 3, 2016: Journal of Mass Spectrometry: JMS
Pravin Kumar, Kedar Mal, G Rodrigues
We report the charge state distributions of the pure, 25% and 50% oxygen mixed krypton plasma to shed more light on the understanding of the gas-mixing and the isotope anomaly [A. G. Drentje, Rev. Sci. Instrum. 63 (1992) 2875 and Y Kawai, D Meyer, A Nadzeyka, U Wolters and K Wiesemann, Plasma Sources Sci. Technol. 10 (2001) 451] in the Electron Cyclotron Resonance (ECR) plasmas. The krypton plasma was produced using a 10 GHz all- permanent-magnet ECR ion source. The intensities of the highly abundant four isotopes viz...
August 24, 2016: Journal of Mass Spectrometry: JMS
Bing Wang, Jinrong Liu, Jungang Cao, Huixin Wang, Xinshu Guan, Zhonglin Wei, Xinhua Guo
Peptide fragments such as b and y sequence ions generated upon low-energy collision induced dissociation (CID) have been routinely used for tandem mass spectrometry (MS/MS) based peptide/protein identification. The underlying formation mechanisms have been studied extensively and described within the literature. As a result, the 'mobile proton model' and 'pathways in competition model' have been built to interpret a majority of peptide fragmentation behavior. However, unusual peptide fragments which involve unfamiliar fragmentation pathways or various rearrangement reactions occasionally appear in MS/MS spectra, resulting in confused MS/MS interpretations...
August 18, 2016: Journal of Mass Spectrometry: JMS
Bjoern Moosmann, Philippe Bisel, Florian Franz, Laura M Huppertz, Volker Auwärter
Designer benzodiazepines represent an emerging class of new psychoactive substances (NPS). While other classes of NPS such as cannabinoid receptor agonists and designer stimulants are mainly consumed for hedonistic reasons, designer benzodiazepines may also be consumed as 'self-medication' by persons with anxiety or other psychiatric disorders or as stand-by 'antidote' by users of stimulant and hallucinogenic drugs. In the present study, five benzodiazepines (adinazolam, cloniprazepam, fonazepam, 3-hydroxyphenazepam, and nitrazolam) and one thienodiazepine (metizolam) offered as 'research chemicals' on the Internet were characterized and their main in vitro phase I metabolites tentatively identified after incubation with pooled human liver microsomes...
August 17, 2016: Journal of Mass Spectrometry: JMS
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