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Journal of Mass Spectrometry: JMS

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https://www.readbyqxmd.com/read/28940471/screening-of-exon-methylation-biomarkers-for-colorectal-cancer-via-lc-ms-ms-strategy
#1
Qionglin Huang, QinjinYang, Mingming Mo, Xiaoxia Ye, Junjie Zhang, Lijian Zhang, Bin Chen, Jian Li, Chun Cai
The identification of biomarkers would be benefit for the diagnosis and treatment of colorectal cancer in clinic. DNA methylation in specific genomic regions, which had shown strongly association with disease genotypes, was effective indicators to reveal the occurrence and development of cancers. To screen out the methylation biomarkers for colorectal cancer (CRC), genomic DNA was isolated from colorectal cancerous and corresponding cancer-adjacent tissues collected from 30 CRC patients and then bisulfite-converted...
September 21, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28929549/uplc-qtof-ms-e-based-diagnostic-product-ion-filtering-to-unveil-unstable-c6-c2-glucoside-conjugates-in-forsythia-suspensa
#2
Yong-Gang Xia, Jun Liang, Xin-Dong Guo, Hui-Min Sun, Hai-Xue Kuang
Forsythia suspensa contains C6 -C2 glucoside conjugates (CCGCs) that are chemically unstable, thereby hindering their isolation and purification. In the present study, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF) was utilized to screen and identify unstable CCGCs in the fruits and leaves of F. suspensa without any tedious isolation and purified process based on independent information acquisition (also called MS(E) ) and individual MS/MS experiments. Diagnostic product ion filtering (DPIF) was further applied to mine unknown analogs in MS(E) high energy levels based on characteristic m/z of key substructures...
September 20, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28929601/conversion-of-benzoic-acid-into-phenol-in-an-itms-under-ci-ms-n-conditions-recognition-of-ortho-chlorobenzoyl-derivatives
#3
Michela Begala
Isomeric chlorobenzoyl cations (m/z 139), under collision induced experiments, fragment identically. Chlorobenzoyl cations can be efficiently converted into cholorophenol radical cations by the reaction with methanol in the ion trap analyser under CI-MS(n) conditions. The substitution of the carbonyl group with a hydroxyl moiety is able to induce an ortho effect, which is absent in the starting ortho-chlorobenzoyl cation. This transformation could be useful to recognize ortho-chlorinated benzoyl derivatives without the need of MS spectra comparison of the whole set of isomers...
September 19, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28892241/seasonal-variations-in-the-profile-of-main-phospholipids-in-mytilus-galloprovincialis-mussels-a-study-by-hydrophilic-interaction-liquid-chromatography-electrospray-ionization-fourier-transform-mass-spectrometry
#4
Laura Facchini, Ilario Losito, Tommaso R I Cataldi, Francesco Palmisano
A systematic characterization of phosphatidylcholines (PC) and phosphatidylethanolamines (PE) in mussels of sp. Mytilus galloprovincialis was performed by high efficiency Hydrophilic Interaction LIquid Chromatography (HILIC) combined with ElectroSpray Ionization (ESI) and Fourier-Transform Mass Spectrometry (FTMS), based on a quadrupole-Orbitrap hybrid spectrometer. FTMS/MS experiments under high-collisional energy dissociation (HCD) conditions, complemented by low energy collisionally induced dissociation (CID) MS(n) (n = 2,3) experiments, performed in a linear ion trap mass spectrometer, were exploited for structural elucidation purposes...
September 11, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28885753/study-of-gas-phase-reactions-of-no2-with-aromatic-compounds-using-proton-transfer-reaction-time-of-flight-mass-spectrometry
#5
Jianquan Li, Xubing Du, Teng Guo, Zhen Peng, Li Xu, Junguo Dong, Ping Cheng, Zhen Zhou
The study of ion chemistry involving the NO2(+) is currently the focus of considerable fundamental interest and is relevant in diverse fields ranging from mechanistic organic chemistry to atmospheric chemistry. A very intense source of NO2(+) was generated by injecting the products from the dielectric barrier discharge (DBD) of a nitrogen and oxygen mixture upstream into the drift tube of a proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) apparatus with H3 O(+) as the reagent ion. The NO2(+) intensity is controllable and related to the DBD operation conditions and ratio of oxygen to nitrogen...
September 8, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28885748/extensive-study-on-physicochemical-properties-of-polychlorinated-biphenyls-in-a-commercial-ion-trap-mass-spectrometer-relevance-in-analytical-and-environmental-chemistry
#6
R Narizzano, F Risso, A Magherini, G Cordone, M Ottonelli, E Smirnova, S Nadotti, L Rivara, R La Rocca, E Magi, S Lottici, S Maggiolo, C E Pepe, M Garbarino
Polychlorinated biphenyls (PCBs) exist as 209 congeners, consisting of biphenyl molecules, where the number and substitution positions of halogen atoms are known to affect industrial uses, environmental transport mechanisms, distribution, fate, and toxicity. The complexity of the problem requires accurate physicochemical studies of an increasing number of congeners in order to understand the environmental and biological processes at play. This work presents a systematic study on the thermodynamic and kinetic properties of PCBs by quadrupole ion trap mass spectrometry...
September 8, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28877381/caffeine-and-glucosamine-mobility-shifts-by-adduction-with-2-butanol-depended-on-interaction-energy-charge-delocalization-and-steric-hindrance-in-ion-mobility-spectrometry
#7
Dairo Meza-Morelos, Roberto Fernandez-Maestre
Ion mobility spectrometry (IMS) is an analytical technique that separates gas-phase ions drifting under an electric field according to their size to charge ratio. We used electrospray ionization-drift tube IMS coupled to quadrupole mass spectrometry to measure the mobilities of glucosamine (GH(+) ) and caffeine (CH(+) ) ions in pure nitrogen or when the shift reagent (SR) 2-butanol was introduced in the drift gas at 6.9 mmol m(-3) . Binding energies of 2-butanol-ion adducts were calculated using Gaussian 09 at the CAMB3LYP/6-311++G(d,p) level of theory...
September 6, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28868667/preparation-of-novel-deuterated-cyclosporin-a-standards-for-quantitative-lc-ms-analysis
#8
Remigiusz Bąchor, Alicja Kluczyk, Piotr Stefanowicz, Zbigniew Szewczuk
The investigation on the synthesis of α-C deuterated analogues of cyclosporine A (CsA) in N-methylated amino acid residues was performed. The reaction based on our previous report (Bachor et al. 2014 J Mass Spectrom 49, 43-49), proceeds in the presence of bases like TBD or MTBD at pH 13.4. The obtained results suggest the possibility of introduction of three deuterons, two at the α-C of sarcosine and one at the chiral α-C atom of 2-N-methyl-(R)-((E)-2-butenyl)-4-methyl-L-threonine residue. The stability of the obtained isotopologues was analyzed both under neutral or acidic conditions and the obtained results revealed that the introduced deuterons do not undergo back-exchange...
September 4, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28865113/investigation-on-the-absolute-and-relative-photoionization-cross-sections-of-three-potential-propargylic-fuels
#9
Matthew Winfough, Giovanni Meloni
Absolute photoionization cross sections for two potential propargylic fuels (propargylamine and dipropargyl ether) along with the partial ionization cross sections for their dissociative fragments are measured and presented for the first time via synchrotron photoionization mass spectrometry. The experimental set-up consists of a multiplexed orthogonal time-of-flight mass spectrometer and is located at the Advanced Light Source facility of the Lawrence Berkeley National Laboratory in Berkeley, California. Data for a third propargylic compound (propargyl alcohol) was taken, however, because of its low signal, due to its weakly bound cation, only the dissociative ionization fragment from the H-loss channel is observed and presented...
September 1, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28865086/fragmentation-of-2-aroylbenzofuran-derivatives-by-electrospray-ionization-tandem-mass-spectrometry
#10
Herbert J Dias, Tatiana M Vieira, Eduardo J Crevelin, Paulo M Donate, Ricardo Vessecchi, Antônio E M Crotti
We investigated the gas-phase fragmentation reactions of a series of 2-aroylbenzofuran derivatives by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The most intense fragment ions were the acylium ions m/z 105 and M+H-C6 H6 ](+) , which originated directly from the precursor ion as a result of two competitive hydrogen rearrangements. Eliminations of CO and CO2 from [M+H-C6 H6 ](+) were also common fragmentation processes to all the analyzed compounds. In addition, eliminations of the radicals •Br and •Cl were diagnostic for halogen atoms at aromatic ring A, whereas eliminations of •CH3 and CH2 O were useful to identify the methoxyl group attached to this same ring...
September 1, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28843012/the-main-beam-correction-term-in-kinetic-energy-release-from-metastable-peaks
#11
Allan Christian Petersen
The correction term for the precursor ion signal width in determination of kinetic energy release is reviewed and the correction term is formally derived. The derived correction term differs from the traditionally applied term. An experimental finding substantiates the inaccuracy in the latter. The application of the 'T-value' to study kinetic energy release is found preferable to kinetic energy release distributions when the metastable peaks are slim and simple Gaussians. For electronically predissociated systems a 'borderline zero' kinetic energy release can be directly interpreted in terms of reaction dynamics with strong curvature in the reaction coordinate...
August 26, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28833875/characterization-of-phenolic-compounds-in-green-and-red-oak-leaf-lettuce-cultivars-by-uhplc-dad-esi-qtof-ms-using-ms-e-scan-mode
#12
Gabriela E Viacava, Sara I Roura, Luis A Berrueta, Carmen Iriondo, Blanca Gallo, Rosa M Alonso-Salces
Lettuce (Lactuca sativa) is one of the most popular leafy vegetables in the world and constitutes a major dietary source of phenolic compounds with health promoting properties. In particular, the demand for green and red oak-leaf lettuces have considerably increased in the last years but few data on their polyphenol composition is available. Moreover, the utilization of analytical edge technology can provide new structural information and allow the identification of unknown polyphenols. In the present study the phenolic profiles of green and red oak-leaf lettuce cultivars were exhaustively characterized by ultrahigh performance liquid chromatography (UHPLC) coupled online to diode array detection (DAD), electrospray ionization (ESI) and quadrupole time-of-flight mass spectrometry (QToF/MS), using the MS(E) instrument acquisition mode for recording simultaneously exact masses of precursor and fragment ions...
August 22, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28806859/analysis-of-low-molecular-weight-compounds-using-maldi-and-ldi-tof-ms-direct-detection-of-active-pharmaceutical-ingredients-in-different-formulations
#13
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
https://www.readbyqxmd.com/read/28801970/lysozyme-oxidation-by-singlet-molecular-oxygen-peptides-characterization-using-18-o-labeling-oxygen-and-nlc-ms-ms
#14
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
https://www.readbyqxmd.com/read/28796372/fragmentation-pathway-and-structural-characterization-of-new-glycosylated-phenolic-derivatives-from-eremanthus-glomerulatus-less-asteraceae-by-electrospray-ionization-tandem-mass-spectrometry
#15
LETTER
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
https://www.readbyqxmd.com/read/28763569/fragmentation-patterns-of-4-5-nitroimidazole-and-1-methyl-5-nitroimidazole-the-effect-of-the-methylation
#16
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
https://www.readbyqxmd.com/read/28762581/remote-detection-of-explosives-using-field-asymmetric-ion-mobility-spectrometer-installed-on-multicopter
#17
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
https://www.readbyqxmd.com/read/28762560/ambient-mass-spectrometry-direct-analysis-of-dimethoate-tebuconazole-and-trifloxystrobin-on-olive-and-vine-leaves-by-desorption-electrospray-ionization-interface
#18
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
https://www.readbyqxmd.com/read/28750482/infrared-ion-spectroscopy-inside-a-mass-selective-cryogenic-2d-linear-ion-trap
#19
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
https://www.readbyqxmd.com/read/28746793/easi-ims-an-expedite-and-secure-technique-to-screen-for-25i-nboh-in-blotter-papers
#20
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
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