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European Journal of Mass Spectrometry

Changchuan Guo, Ke Li, Sheng Xing, Hua Sun, Feng Shi, Guifang Zhang, Haiyan Sun
In this work, a method combining ultra-high performance liquid chromatography and hybrid quadrupole-Orbitrap high-resolution mass spectrometry (HR-MS) was developed and validated for use in the simultaneous screening, identification, and quantification of 21 synthetic dyes in herbal medicines. To optimize the chromatographic conditions, we used a combined Full mass scan and data-dependent MS/MS (Full MS/dd-MS2 ) approach in positive and negative ion mode. Under this mode, selected ions with given fragmentation energy were subjected to a dd-MS2 scan following a Full MS scan...
February 14, 2019: European Journal of Mass Spectrometry
Dhiman Halder, Shubhasis Dan, Pradipta Sarkar, Dibya Das, Umesh Chandra Halder, Tapan Kumar Pal
A simple and highly sensitive bioanalytical method was developed and validated for simultaneous quantification of nimesulide (NSD) and its active metabolite 4-hydroxy-nimesulide (M1) in human plasma by liquid chromatography-tandem mass spectrometer (LC-MS/MS) and applied in a bioequivalence study performed on Indian subjects. The bioanalytical method was carried out by LC-MS/MS with celecoxib (CXB) as an internal standard (IS) using liquid-liquid extraction technique. The chromatographic separation was performed on a reversed-phase Agilent eclipse plus C18 (75 mm × 4...
January 29, 2019: European Journal of Mass Spectrometry
David Touboul
Using a modified atmospheric pressure photoionization (APPI) source coupled to a tunable vacuum ultraviolet source at the SOLEIL synchrotron radiation facility, we determined the appearance energy of protonated methanol monomer and dimers at different source temperatures. The experimental data indicated that protonated monomers can be formed through the direct photoionization of neutral methanol by the second emission band of a krypton discharge UV lamp at 116.49 nm (10.64 eV) explaining why methanol can be considered as a weak dopant under APPI conditions...
January 16, 2019: European Journal of Mass Spectrometry
Denis Lesage, Sakina Mezzache, Yves Gimbert, Héloïse Dossmann, Jean-Claude Tabet
Proline proton affinity PA(Pro) was previously measured by extended kinetic methods with several amines as reference bases using a triple quadrupole mass spectrometer ( J Mass Spectrom 2005; 40: 1300). The measured value of 947.5 ± 5 kJ.mol-1 differs by more than 10 kJ.mol-1 from previous reported experimental or calculated values. This difference may be explained in part by the existence of relatively large entropy difference between the two dissociation channels (ΔΔS‡ avg  = 31 ± 10 J...
January 10, 2019: European Journal of Mass Spectrometry
Manja Wölter, Manuela Russ, Charles A Okai, Werner Rath, Ulrich Pecks, Michael O Glocker
Mass spectrometric profiling of intact serum proteins, i.e. determination of relative protein abundance differences, was performed using two different serum sample preparation methods: one with frozen and thawed serum, the other with at room temperature deposited and dried serum. Since in a typical clinical setting freezing of serum is difficult to achieve, sampling at room temperature is preferred and can be met when using the Noviplex™ card system. Once deposited and dried, serum proteins can be stored and shipped at room temperature...
December 26, 2018: European Journal of Mass Spectrometry
Lidia Podniesińska, Rafał Frański, Magdalena Frańska
The electrospray ionization (ESI) responses, defined as the area of chromatographic peak of ion [M+H]+ obtained upon HPLC/ESI-MS analysis, of three β-lactam antibiotics, namely penicillin G, ampicillin and carbenicillin have been compared with the ESI responses of their methanolysis products. It has been found that methanolyzed penicillin G has much higher ESI response than the penicillin G. Methanolyzed ampicillin also has higher ESI response than ampicillin; however, the effect is less pronounced than for penicillin...
December 24, 2018: European Journal of Mass Spectrometry
Bryan D Linford, Andrea Le Donne, Debora Scuderi, Enrico Bodo, Travis D Fridgen
The gas-phase structure of protonated β-methylaminoalanine was investigated using infrared multiple photon dissociation spectroscopy in the C-H, N-H, O-H stretching region (2700-3800 cm-1 ) and the fingerprint region (1000-1900 cm-1 ). Calculations using density functional theory methods show that the lowest energy structures prefer protonation of the secondary amine. Formation of hydrogen bonds between the primary and secondary amine, and the secondary amine and carboxylic oxygen further stabilize the lowest energy structure...
December 18, 2018: European Journal of Mass Spectrometry
Edebi N Vaikosen, Lorraine T Gibson, Christine M Davidson, Bamidele I Olu-Owolabi, Kayode Adebowale, Benjamin U Ebeshi, Paul Ne Diagboya
Most environmental analytical methods for the determination of organochlorine pesticides (OCPs) are multi-residual with other organic compounds co-extracted and co-eluted. This has been observed in GC spectra using classical detectors like electron-capture detector (ECD) even after appropriate clean-up. This limitation could be resolved by using GC-MS methods which are more specific and selective. Thus, a commercial-grade endosulfan treated Theobroma cacao plantation was sampled. Representative samples comprising leaves, stem bark and pulp were obtained between 0...
December 18, 2018: European Journal of Mass Spectrometry
Emilien L Jamin, Carine Jacques, Laëtitia Jourdes, Jean-Claude Tabet, Nathalie Borotra, Sandrine Bessou-Touya, Laurent Debrauwer, Hélène Duplan
The stratum corneum, the outermost layer of the epidermis, is the most important skin barrier against exogenous physical and chemical effects, in addition to protecting against dehydration. Ceramides are integral parts of the intercellular lipid lamellae of the stratum corneum and play an important role in the barrier function of mammalian skin. Ceramides are sphingolipids consisting of sphingoid bases linked to fatty acids by an amide bond. Typical sphingoid bases in the skin are composed of dihydrosphingosine, sphingosine, phytosphingosine, and 6-hydroxysphingosine, and the fatty acid acyl chains are composed of non-hydroxy fatty acid, α-hydroxy fatty acid, ω-hydroxy fatty acid, and esterified ω-hydroxy fatty acid...
December 13, 2018: European Journal of Mass Spectrometry
Sireesha Dodda, Ajitha Makula, Srinivasa R Polagani, Raj N Kandhagatla
A method for bioanalysis of pentoxifylline in human plasma was developed using liquid chromatography-tandem mass spectrometry, which is simple, specific, and sensitive. Pentoxifylline D5 was used as the internal standard. Employing only 100 µl of human plasma, processing was done with solid-phase extraction technique. The analyte and the internal standard were separated from endogenous components on Ace phenyl column using a mixture of 5 mM ammonium acetate buffer and high performance liquid chromatography grade acetonitrile (60:40, v/v) as mobile phase at a flow rate of 1 ml/min...
December 10, 2018: European Journal of Mass Spectrometry
Cameron J Owen, Georgia C Boles, Giel Berden, Jos Oomens, P B Armentrout
The gas-phase structures of zinc and cadmium complexes of lysine (Lys) are investigated via a combination of infrared multiple photon dissociation action spectroscopy and ab initio quantum chemical calculations. In order to unambiguously identify the experimentally observed species, [Zn(Lys-H)]+ and CdCl+ (Lys), the action spectra were compared to linear absorption spectra calculated at the B3LYP level of theory, using 6-311+G(d,p) and def2-TVZP basis sets for the zinc and cadmium systems, respectively. Single point energies were also calculated at the B3LYP, B3P86, MP2, and B3LYP-GD3BJ (accounting for empirical dispersion) levels of theory using larger basis sets...
December 7, 2018: European Journal of Mass Spectrometry
Bijay Banstola, Carson W Szot, Achala P Deenamulla Kankanamalage, Kermit K Murray
We have developed a new actuation method for matrix-assisted ionization with good temporal and spatial resolution using piezoelectric cantilever. A strike from the piezoelectric bimorph cantilever on a thin metal foil was used to remove materials deposited on the opposite side facing the mass spectrometer inlet. Highly charged ions of peptides and proteins were generated from dried droplet deposits and sampled into the inlet of the mass spectrometer. A lateral resolution of 1 mm was obtained with the piezoelectric sampling configuration...
December 7, 2018: European Journal of Mass Spectrometry
Virginie Domalain, Marie Hubert-Roux, Laurence Quéguiner, Dany Jd Fouque, Eric Arnoult, David Speybrouck, Jérôme Guillemont, Carlos Afonso
Mycobacterium tuberculosis infection results in more than two million deaths per year and is the leading cause of mortality in people infected with HIV. A new structural class of antimycobacterials, the diarylquinolines, has been synthesized and is being highly effective against both M. tuberculosis and multidrug-resistant tuberculosis. As diarylquinolines are biologically active only under their ( R,S) stereoisomeric form, it is essential to differentiate the stereoisomers ( R,S) and ( R,R). To achieve this, tandem mass spectrometry and ion mobility spectrometry-mass spectrometry have been performed with 10 diarylquinoline diastereomers couples...
December 5, 2018: European Journal of Mass Spectrometry
Daniel R Fuller, Christopher R Conant, Tarick J El-Baba, Zhichao Zhang, Kameron R Molloy, Connie S Zhang, David A Hales, David E Clemmer
Biomolecular degradation plays a key role in proteostasis. Typically, proteolytic enzymes degrade proteins into smaller peptides by breaking amino acid bonds between specific residues. Cleavage around proline residues is often missed and requires highly specific enzymes for peptide processing due to the cyclic proline side-chain. However, degradation can occur spontaneously (i.e. in the absence of enzymes). In this study, the influence of the first residue on the stability of a series of penultimate proline containing peptides, with the sequence Xaa-Pro-Gly-Gly (where Xaa is any amino acid), is investigated with mass spectrometry techniques...
February 2019: European Journal of Mass Spectrometry
Qiuyan Jin, Jiaye Li, Alireza Ariafard, Allan J Canty, Richard Aj O'Hair
Gas-phase ion trap mass spectrometry experiments and density functional theory calculations have been used to examine the routes to the formation of the 1,8-naphthyridine (napy) ligated geminally dimetallated phenyl complexes [(napy)Cu2 (Ph)]+ , [(napy)Ag2 (Ph)]+ and [(napy)CuAg(Ph)]+ via extrusion of CO2 or SO2 under collision-induced dissociation conditions from their corresponding precursor complexes [(napy)Cu2 (O2 CPh)]+ , [(napy)Ag2 (O2 CPh)]+ , [(napy)CuAg(O2 CPh)]+ and [(napy)Cu2 (O2 SPh)]+ , [(napy)Ag2 (O2 SPh)]+ , [(napy)CuAg(O2 SPh)]+ ...
February 2019: European Journal of Mass Spectrometry
Evan Perez, Theodore A Corcovilos, John K Gibson, Jonathan Martens, Giel Berden, Jos Oomens, Michael J Van Stipdonk
Electrospray ionization was used to generate species such as [ZnNO3 (CH3 OH)2 ]+ from Zn(NO3 )2 •XH2 O dissolved in a mixture of CH3 OH and H2 O. Collision-induced dissociation of [ZnNO3 (CH3 OH)2 ]+ causes elimination of CH3 OH to form [ZnNO3 (CH3 OH)]+ . Subsequent collision-induced dissociation of [ZnNO3 (CH3 OH)]+ causes elimination of 47 mass units (u), consistent with ejection of HNO2 . The neutral loss shifts to 48 u for collision-induced dissociation of [ZnNO3 (CD3 OH)]+ , demonstrating the ejection of HNO2 involves intra-complex transfer of H from the methyl group methanol ligand...
February 2019: European Journal of Mass Spectrometry
Morgan Stickney, Qiangwei Xia, I Jonathan Amster
Capillary zone electrophoresis (CZE) paired with mass spectrometry (MS) is a powerful analytical technique for examining mixtures of ionic analytes such as glycosaminoglycans. This study examines the mechanics of the electrospray process for a sheath flow CZE-MS interface under reverse polarity negative ionization conditions. Liquid flow in a sheath flow nano-electrospray CZE-MS interface is driven by two mechanisms, electroosmotic flow and electrospray nebulization. The contribution of these two processes to the overall flow of solution to the electrospray tip is influenced by the surface coatings of the sheath flow emitter tip and by the solvent composition...
February 2019: European Journal of Mass Spectrometry
Jialin Mao, Wei Zhang, Stephen Zd Cheng, Chrys Wesdemiotis
Monodisperse, sequence-defined polymers can be potentially used for digital data storage. This study reports the sequence analysis and differentiation of monodisperse polyester copolymers carrying side chains functionalized in a specific order by polyhedral oligomeric silsesquioxane (POSS) nanoparticles. Steglich esterification and succinic anhydride ring-opening chemistries were utilized iteratively to synthesize the intended sequences, which were characterized by matrix-assisted laser desorption ionization tandem mass spectrometry (MALDI-MS2 )...
February 2019: European Journal of Mass Spectrometry
Mary T Rodgers
No abstract text is available yet for this article.
February 2019: European Journal of Mass Spectrometry
Peter B Armentrout, Thomas Baer, Jesse Jack L Beauchamp, Jos Oomens, Mary T Rodgers, Victor Ryzhov
No abstract text is available yet for this article.
February 2019: European Journal of Mass Spectrometry
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