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Journal of Mass Spectrometry: JMS

João L Bronzel, Cintia D F Milagre, Humberto M S Milagre
Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) is a high throughput, easy to use analytical technique. The simple sample preparation of this technique and its tolerance to the presence of contaminants are among its advantages. In contrast, depending on the matrix used, MALDI can ionize and generates ions in the low m/z range that complicate the interpretation of the spectra of low molecular weight compounds. To address this issue, one can envisage the use of tunable ionic matrices that can reduce the low m/z interferents...
August 14, 2017: Journal of Mass Spectrometry: JMS
Emerson Finco Marques, Marisa H G Medeiros, Paolo Di Mascio
Singlet molecular oxygen ((1) O2 ) is generated in biological systems and reacts with different biomolecules. Proteins are a major target for (1) O2 and His, Tyr, Met, Cys and Trp are oxidized at physiological pH. In the present study, the modification of lysozyme protein by (1) O2 was investigated using mass spectrometry approaches. The experimental findings showed methionine, histidine and tryptophan oxidation. The experiments were achieved using [(18) O]-labeled (1) O2 released from thermolabile endoperoxides in association with nano-scale liquid chromatography coupled to electrospray ionization mass spectrometry, an UHR-ESI-Q-TOF...
August 11, 2017: Journal of Mass Spectrometry: JMS
Juliano Geraldo Amaral, Anelize Bauermeister, Alan Cesar Pilon, Dayana Rubio Gouvea, Humberto Takeshi Sakamoto, Leonardo Gobbo-Neto, João Luis Callegari Lopes, Norberto Peporine Lopes
No abstract text is available yet for this article.
August 10, 2017: Journal of Mass Spectrometry: JMS
Eero Itälä, Katrin Tanzer, Sari Granroth, Kuno Kooser, Stephan Paul Denifl, Edwin Kukk
We present here the photofragmentation patterns of doubly ionized 4(5)-nitroimidazole and 1-methyl-5-nitroimidazole. The doubly ionized state was created by core ionizing the C 1s orbitals of the samples, rapidly followed by Auger decay. Due to the recent development of nitroimidazole-based radiosensitizing drugs, core ionization was selected as it represents the very same processes taking place under the irradiation with medical X-rays. In addition to the fragmentation patterns of the sample, we study the effects of methylation on the fragmentation patterns of nitroimidazoles...
August 1, 2017: Journal of Mass Spectrometry: JMS
Yury Kostyukevich, Denis Efremov, Vladimir Ionov, Eugene Kukaev, Eugene Nikolaev
The detection of explosives and drugs in hard-to-reach places is a considerable challenge. We report the development and initial experimental characterization of the air analysis system that includes Field Asymmetric Ion Mobility Spectrometer (FAIMS), array of the semiconductor gas sensors and is installed on multicopter. The system was developed based on the commercially available DJI Matrix 100 platform. For data collection and communication with operator, the special compact computer (Intel Compute Stick) was installed onboard...
August 1, 2017: Journal of Mass Spectrometry: JMS
Lucia Mainero Rocca, Juri Cecca, Nunziata L'Episcopo, Giovanni Fabrizi
A new field of application for a relatively new mass-spectrometric interface such as desorption electrospray ionization was evaluated. For this purpose, its behavior was tested versus quantitative analysis of dimethoate, trifloxystrobin and tebuconazole directly on olive and vine leaves surface. The goal was workers exposure assessment during field re-entry operations since evidence suggests an association between chronic occupational exposure to some agrochemicals and severe adverse effects. DESI gave good response working in positive ionization mode, while numerous test were necessary for the choice of a unique blend of spray solvents suitable for all three substances...
August 1, 2017: Journal of Mass Spectrometry: JMS
Adam P Cismesia, Larry F Tesler, Matthew R Bell, Laura S Bailey, Nicolas C Polfer
We demonstrate operation of the first cryogenic 2D linear ion trap (LIT) with mass-selective capabilities. This trap presents a number of advantages for infrared ion "action" spectroscopy studies, particularly those employing the "tagging/messenger" spectroscopy approach. The high trapping efficiencies, trapping capacities, and low detection limits make 2D LITs a highly suitable choice for low-concentration analytes from scarce biological samples. In our trap, ions can be cooled down to cryogenic temperatures to achieve higher-resolution infrared spectra, and individual ions can be mass selected prior to irradiation for a background-free photodissociation scheme...
July 27, 2017: Journal of Mass Spectrometry: JMS
Damila Rodrigues de Morais, Ingrid Lopes Barbosa, Kelly Francisco Cunha, Guilherme Lucas Tripodi, Célio Fernando Figueiredo Angolini, Marcos Fernando Franco, Elvis Medeiros de Aquino, Marcos Nogueira Eberlin, Jose Luiz Costa
The increasing number of new psychoactive substances (NPS) and their quick worldwide spreading, often only slightly modified in the form of new derivatives and analogues, have brought the need for fast, wide-ranging and unequivocal identification methods in clinical and forensic investigations. Since it usually provides secure results, gas chromatography coupled to mass spectrometry (GC-MS) has been routinely employed as the standard technique for the detection of NPS in blotter papers. For 25I-NBOH (N-(2-hydroxybenzyl)-2-(4-iodo-2,5-dimethoxyphenyl)ethan-1-aminium), however, GC-MS analysis of an blotter paper extract leads to incorrect results...
July 26, 2017: Journal of Mass Spectrometry: JMS
Matias Butler, Gabriela M Cabrera
2-mercaptopyridine N-oxide (pyrithione, PTOH) along with several transition metal ions forms coordination compounds displaying notable biological activities. Gas-phase complexes formed between pyrithione and Manganese (II), Cobalt (II), Nickel (II), Copper (II) and Zinc (II) were investigated by infusion in the electrospray source of a quadrupole-time of flight mass spectrometer. Remarkably, positive ion mode spectra displayed the singly charged metal adduct ion [C10 H8 MN2 O2 S2 ](2+) ([M(PTO)2 ](+•) or [M(DPTO)](+•) ), where DPTO is dipyrithione, 2,2'-dithiobis(pyridine N-oxide), among the most abundant peaks, implying a change in the oxidation state of whether the metal ion or the ligands...
July 24, 2017: Journal of Mass Spectrometry: JMS
Ester Oras, Signe Vahur, Sven Isaksson, Ivari Kaljurand, Ivo Leito
Soft-ionization methods are currently at the forefront of developing novel methods for analysing degraded archaeological organic residues. Here we present little-used soft ionisation method of matrix assisted laser desorption/ionization - Fourier transform - ion cyclotron resonance - mass spectrometry (MALDI-FT-ICR-MS) for the identification of archaeological lipid residues. It is a high-resolution and sensitive method with low limits of detection capable of identifying lipid compounds in small concentrations, thus providing a highly potential new technique for the analysis of degraded lipid components...
July 24, 2017: Journal of Mass Spectrometry: JMS
Ákos Kuki, Lajos Nagy, Miklós Zsuga, Sándor Kéki
The classical semi-quantitative Rice-Ramsperger-Kassel (RRK) theory was used for the calculation of the internal energy dependent reaction rate coefficient of the collision-induced dissociation (CID) reaction in tandem mass spectrometry (MS/MS). The survival yield (SY) was determined by the reaction rate equation for the unimolecular dissociation of the precursor ion. The parameters of the rate equation and the RRK model were approximated based on the instrumental conditions. We used the RRK equation for the description of the basic behavior of the fragmentation reactions and for the estimation of the internal energy of the precursor ion...
July 21, 2017: Journal of Mass Spectrometry: JMS
Argitxu Esquivel, Xavier Matabosch, Aristotelis Kotronoulas, Georgina Balcells, Jesús Joglar, Rosa Ventura
Studies on steroid metabolism are of utmost importance to improve the detection capabilities of anabolic androgenic steroids (AAS) misuse in sports drug testing. In humans, glucuronoconjugates are the most abundant phase II metabolites of AAS. Bis-glucuronidation is a reaction where two separated functional groups on the same molecule are conjugated with glucuronic acid. These metabolites have not been studied in depth for steroids and could be interesting markers for doping control. The aim of the present work was to study the ionization and collision induced dissociation of steroid bis-glucuronides to be able to develop mass spectrometric analytical strategies for their detection in urine samples after AAS administration...
July 21, 2017: Journal of Mass Spectrometry: JMS
David Bongiorno, Valentina Calabrese, Leopoldo Ceraulo, Serena Indelicato, Vincenzo Turco Liveri
The ability of positively charged aggregates of the surfactant (1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) to incorporate D- or L-tryptophan in the gas-phase has been investigated by electrospray ion mobility mass spectrometry (ESI-IM-MS). Strongly impacted by the pH of the electrosprayed solutions, both protonated (T(+) ) and deprotonated (T(-) ) tryptophan are effectively included into the aggregates whereas, tryptophan in zwitterionic (T(0) ) form is practically absent in singly charged DMEB aggregates but can be found in multiply charged ones...
July 21, 2017: Journal of Mass Spectrometry: JMS
Yunfeng Chai, Yunlong Shao, Lu Wang, Lin Wang
In electrospray ionization tandem mass spectrometry of protonated 1-benzoylamines (1-benzoylpiperadine, 1-benzoylmorpholine, and 1-benzoyl-4-methylpiperazine), the dominant fragmentation pathway was amide bond cleavage to form benzoyl cation and neutral amine. Meanwhile, in their fragmentations, an interesting loss of benzaldehyde (106 Da) was observed and identified to derive from hydride transfer reaction between the benzoyl cation and amine. A stepwise mechanism for loss of 106 Da (benzene and CO) could be excluded with the aid of deuterium labeling experiment...
July 14, 2017: Journal of Mass Spectrometry: JMS
Vadim Shevyrin, Yuri Shafran
Differentiation of new psychoactive substance (NPS), 6-(2-methylaminopropyl)benzofuran (6-MAPB), and its positional isomer, 2-(2-methylaminopropyl)benzofuran (2-MAPB), by means of gas chromatography/mass spectrometry (GC/MS) with quadrupole detection is ambiguous. Reliable distinguishing of the two isomers could be achieved by MS/MS spectra recorded after collision-induced dissociation (CID) of precursor ions. Both electron ionization (EI) and electrospray ionization (ESI) methods could be used for these purposes...
July 14, 2017: Journal of Mass Spectrometry: JMS
A F Lago, R D Januário, R L Cavasso Filho, M Simon, J Z Dávalos
Time of flight mass spectrometry, electron-ion coincidence and ion yield spectroscopy were employed to investigate for the first time the thiazole (C3 H3 NS) molecule in the gas phase excited by synchrotron radiation in the soft X-ray domain. Total Ion Yield and PEPICO spectra were recorded as a function of the photon energy in the vicinity of the carbon K edge (C1s). The C1s resonant transitions as well as the core ionization thresholds have been determined from the profile of TIY spectrum and the features were discussed...
July 12, 2017: Journal of Mass Spectrometry: JMS
Cuizhu Wang, Nanqi Zhang, Zhenzhou Wang, Zeng Qi, Bingzhen Zheng, Pingya Li, Jinping Liu
Platycodon grandiflorum (PG) is extensively used for treating cough, excessive phlegm, sore throat, bronchitis and asthma. Whereas Adenophora stricta (AS) is commonly used to reduce phlegm, clear lung and tonify stomach. Due to similar appearances, PG is sometimes adulterated with cheap AS so as to gain profits. And this will inevitably result in different pharmacological property. In order to further clarify the differences in the chemical composition of these two Chinese herbs, the ultra-high performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) coupled with UNIFI platform was used to establish a reliable, simple, sensitive and rapid analytical method...
July 7, 2017: Journal of Mass Spectrometry: JMS
Svetlana Tsizin, Boaz Seemann, Tal Alon, Aviv Amirav
We report the observation of a new physical phenomenon of the addition of two hydrogen atoms to molecular ions thus forming [M+2H](+) ions. We demonstrate such second hydrogen atom abstraction onto the molecular ions of pentaerythritol and trinitrotoluene (TNT). We used both GC-MS with supersonic molecular beam (SMB) with methanol added into its make-up gas and electron ionization LC-MS with SMB with methanol as the LC solvent. We found that the formation of methanol clusters resulted upon electron ionization in the formation of dominant protonated pentaerythritol ion at m/z=137 plus about 70% relative abundance of pentaerythritol molecular ion with two additional hydrogen atoms at m/z=138 which is well above the 5...
July 7, 2017: Journal of Mass Spectrometry: JMS
M Peng, S Li, J Wu, Y Guo, S Cao, Y Zhao
Sartans and related analogues with 5-oxo-l, 2, 4-oxadiazole ring and tetrazole ring are investigated in detail using collision-induced dissociation (CID) method in positive ion mode by electrospray ionization tandem mass spectrometry (ESI-MS(n) ). It is found that, the protonated sartans and related analogues tend to form the N-substituted-3- substituted phenanthridin-6-amine ion which has a large conjugative structure. The possible fragmentation pathways were proposed for the first time, and the key structure of product ions were confirmed by high resolution tandem mass spectrometry and theoretical calculation...
July 5, 2017: Journal of Mass Spectrometry: JMS
T Fouquet, R B Cody, H Sato
No abstract text is available yet for this article.
July 3, 2017: Journal of Mass Spectrometry: JMS
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