Read by QxMD icon Read

Journal of Mass Spectrometry: JMS

Niclas Nikolai Stephanson, Patrick Signell, Anders Helander, Olof Beck
The influx of new psychoactive substances (NPS) has created a need for improved methods for drug testing in toxicology laboratories. The aim of this work was to design, validate and apply a multi-analyte liquid chromatography-high resolution mass spectrometry (LC-HRMS) method for screening of 148 target analytes belonging to the NPS class, plant alkaloids and new psychoactive therapeutic drugs. The analytical method used a five-fold dilution of urine with 9 deuterated internal standards and injection of 2 μL...
May 10, 2017: Journal of Mass Spectrometry: JMS
Marianne Engeser, Christian Mundt, Christoph Bauer, Stefan Grimme
Electron ionisation mass spectra of N-methylimidazolidin-4-one organocatalysts were studied by experimental and theoretical means. The molecular ions mostly undergo alpha cleavages of exocyclic substituents that leave the five-membered ring intact. The type of substituent strongly dominates the appearance of the spectra. Fragmentation cascades are corroborated by metastable ion mass spectra. Quantum Chemistry Electron Ionization Mass Spectra calculations correlate reasonably well with the experimental electron ionization spectra and reveal mechanistic details of fragmentation pathways...
May 8, 2017: Journal of Mass Spectrometry: JMS
Jean-Arthur Amalian, Abdelaziz Al Ouahabi, Gianni Cavallo, Niklas Felix König, Salomé Poyer, Jean-François Lutz, Laurence Charles
Digital polymers are monodisperse chains with a controlled sequence of co-monomers, defined as letters of an alphabet, and are used to store information at the molecular level. Reading such messages is hence a sequencing task that can be efficiently achieved by tandem mass spectrometry. To improve their readability, structure of sequence-controlled synthetic polymers can be optimized, based on considerations regarding their fragmentation behavior. This strategy is described here for poly(phosphodiester)s, that were synthesized as monodisperse chains with more than 100 units but exhibited extremely complex dissociation spectra...
May 8, 2017: Journal of Mass Spectrometry: JMS
Zhihui Yin, Changhai Sun, Hongzhuang Fang
This work aims to analyze the electrospray ionization multistage mass spectrometry (ESI-MS(n) ) fragmentation characteristics of hydroxycinnamic acids (HCAs) in negative ion mode. The geometric parameters, energies, natural bond orbitals and frontier orbitals of fragments were calculated by density functional theory (DFT) to investigate mass spectral fragmentation mechanisms. The results showed that proton transfer always occurred during fragmentation of HCAs; their quasi-molecular ions ([M-H](-) ) existed in more than one form and were mainly with the lowest energy...
May 8, 2017: Journal of Mass Spectrometry: JMS
David Rodriguez-Temporal, Daniel Perez-Risco, Eduardo A Struzka, Mireia Mas, Fernando Alcaide
Conventional identification of mycobacteria species is slow, laborious and has low discriminatory power. MALDI-TOF MS has proved highly effective for identifying conventional bacteria, and it may also be useful for identifying mycobacteria. The aim of this study was to evaluate and compare MALDI-TOF MS with currently recommended molecular methods for the identification of nontuberculous mycobacteria (NTM), applying Mycobacteria Libraries v3.0 (ML3.0) and v2.0 (ML2.0). A total of 240 clinical isolates of 41 NTM species grown on solid media were analysed: 132 isolates of slow-growing mycobacteria and 108 of rapid-growing mycobacteria...
May 8, 2017: Journal of Mass Spectrometry: JMS
Anu Teearu, Signe Vahur, Toomas Rodima, Koit Herodes, Werner Bonrath, Thomas Netscher, Sofja Tshepelevitsh, Aleksander Trummal, Märt Lõkov, Ivo Leito
Matrix-assisted laser desorption/ionization (MALDI) is a mass spectrometry (MS) ionization technique suitable for a wide variety of sample types including highly complex ones such as natural resinous materials. Coupled with Fourier transform ion cyclotron resonance (FT-ICR) mass analyzer, which provides mass spectra with high resolution and accuracy, the method gives a wealth of information about the composition of the sample. One of the key aspects in MALDI-MS is the right choice of matrix compound. We have previously demonstrated that 2,5-dihydroxybenzoic acid (DHB) is suitable for the positive ion mode analysis of resinous samples...
May 4, 2017: Journal of Mass Spectrometry: JMS
Lu Wang, Yali Wang, Yunfeng Chai, Yu Kang, Cuirong Sun, Su Zeng
A facile method based on electrospray mass spectrometry was established and validated for the differentiation of enantiomeric Tadalafil isomers without using chiral chromatographic separation. The enantiomers were coupled with a chiral selector to form diastereomeric complex ions. Nickel-Tadalafil complexes, [Ni(II) (Tadalafil)(L-Trp)-H](+) , produced a characteristic fragment ion at m/z 524 by loss of 1-methyl-1, 6-dihydropyrazine-2, 5-dione (MDD) via collision-induced dissociation (CID). The relative abundance of this fragment ion to the precursor contributed to differentiate Tadalafil enantiomers, and energy-resolved product-ion spectra were applied to determine molar composition of Tadalafil in the mixture (R, R and S, S) as well...
May 4, 2017: Journal of Mass Spectrometry: JMS
Sebastian Beck, Sabrina Trog, Sarah Knizia, Michael W Linscheid
1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) is a macrocycle that is able to complexate a large variety of metals. The stability of these metal complexes is generally very high. This has led to the use of these complexes in medical applications, e.g. magnetic resonance imaging. Here, we have investigated the fragmentation behavior of a number of DOTA-metal complexes under collision-induced dissociation (CID), infrared-multiphoton dissociation (IRMPD) and higher-energy collisional dissociation (HCD) activation conditions...
April 28, 2017: Journal of Mass Spectrometry: JMS
Uri Keshet, Tal Alon, Alexander B Fialkov, Aviv Amirav
An Open Probe inlet was combined with a low thermal mass ultra-fast gas chromatograph (GC), in-vacuum electron eonization (EI) ion source and a mass spectrometer (MS) of GC-MS for obtaining real time analysis with separation. The Open Probe enables ambient sampling via sample vaporization in an oven that is open to room air and the ultra-fast GC provides ~30 s separation while if no separation is required it can act as a transfer line with 2-3 s sample transfer time. Sample analysis is as simple as touching the sample, pushing the sample holder into the open probe oven and getting the results in 30 s...
April 28, 2017: Journal of Mass Spectrometry: JMS
Feifan Xie, Pieter Colin, Jan Van Bocxlaer
Non-enzyme dependent hydrolysis of the drug cisplatin is important for its mode of action and toxicity. However, up until today, the hydrolysis process of cisplatin is still not completely understood. In the present study, the hydrolysis of cisplatin in an aqueous solution was systematically investigated using electrospray ionization mass spectrometry coupled to liquid chromatography. A variety of previously unreported hydrolysis complexes corresponding to mono-, di-, and trimeric species were detected and identified...
April 26, 2017: Journal of Mass Spectrometry: JMS
Nidia Lauzon, Martin Dufresne, Alexandre Beaudoin, Pierre Chaurand
Silver-assisted laser desorption ionization (AgLDI) imaging mass spectrometry (IMS) has been demonstrated to be a useful technology for fingermark analysis allowing for the detection of several classes of endogenous as well as exogenous compounds. Ideally, in IMS analyses, the fingermarks are deposited under controlled conditions on metallized conductive target slides. However, in forensic investigations, fingermarks are often found on a variety of non-conductive surfaces. A sputtered silver layer renders the target surface conductive, which allows the analyses of insulating surfaces by time-of-flight (TOF) IMS...
April 26, 2017: Journal of Mass Spectrometry: JMS
Yan-Chun Liu, Sa Xiao, Kun Yang, Li Ling, Zhi-Liang Sun, Zhao-Ying Liu
This study reports an applicable analytical strategy of comprehensive identification and structure characterization of target components from Gelsemium elegans by using high-performance liquid chromatography quadruopole time-of-flight mass spectrometry (LC-QqTOF MS) based on the use of accurate mass databases combined with MS/MS spectra. The databases created included accurate masses and elemental compositions of 204 components from Gelsemium and their structural data. The accurate MS and MS/MS spectra were acquired through data-dependent auto MS/MS mode followed by an extraction of the potential compounds from the LC-QqTOF MS raw data of the sample...
April 26, 2017: Journal of Mass Spectrometry: JMS
Angelo Palmigiano, Rosaria Ornella Bua, Rita Barone, Daisy Rymen, Luc Régal, Nicolas Deconinck, Carlo Dionisi-Vici, Cheuk-Wing Fung, Domenico Garozzo, Jaak Jaeken, Luisa Sturiale
Congenital disorders of glycosylation (CDG) are due to defective glycosylation of glycoconjugates. COG-CDG are genetic diseases due to defects of the conserved oligomeric Golgi (COG) complex subunits 1-8 causing N- and O-glycan processing abnormalities. In COG-CDG, IEF separation of undersialylated glycoforms of serum transferrin and apolipoprotein C-III (apoC-III) allows to detect N- and O-glycosylation defects respectively. COG5-CDG (COG5 subunit deficiency) is a multisystem disease with dysmorphic features, intellectual disability of variable degree, seizures, acquired microcephaly, sensory defects and autistic behavior...
April 25, 2017: Journal of Mass Spectrometry: JMS
Martin L Schmidt, Marianne Engeser
N-methylimidazolidin-4-one organocatalysts were studied in the gas phase. Protonated and sodium-cationized (sodiated) molecules are conveniently accessible by electrospray mass spectrometry. Protonation enables three different closed-shell paths of ring cleavage leading to iminium ions. The fragmentation pattern is largely unaffected by exocyclic substituents and thus is valuable to characterize the substance type as N-methylimidazolidin-4-ones. Sodiated species show a distinctly different fragmentation which is less useful for characterization purposes: Apart from signal loss due dissociaton of Na(+) , the observation of benzyl radical loss is by far predominant...
April 18, 2017: Journal of Mass Spectrometry: JMS
Olena Kudina, Huseyin Burak Eral, Frieder Mugele
We recently showed that electrowetting-enhanced sample preparation for MALDI-MS (eMALDI) can increase the intensity of the MALDI signal by 2-25 times compared to conventional drop drying by concentrating all the dried sample in a single spot rather than leaving behind a heterogeneous coffee stain pattern. Here, we demonstrate that the eMALDI signal enhancement can be further increased to more than 100x by systematically optimizing the electrowetting actuation frequency and amplitude. This enables 30x signal increase for a peptide standard...
April 18, 2017: Journal of Mass Spectrometry: JMS
Huiyan Li, Jun Han, Jingxi Pan, Teng Liu, Carol E Parker, Christoph H Borchers
Proteins can provide insights into biological processes at the functional level, so they are very promising biomarker candidates. The quantification of proteins in biological samples has been routinely used for the diagnosis of diseases and monitoring the treatment. Although large-scale protein quantification in complex samples is still a challenging task, a great amount of effort has been made to advance the technologies that enable quantitative proteomics. Seven years ago, in 2009, we wrote an article about the current trends in quantitative proteomics...
April 18, 2017: Journal of Mass Spectrometry: JMS
Mays Al-Dulaymi, Anas El-Aneed
Diquaternary ammonium gemini Surfactants have emerged as effective gene delivery vectors. A novel series of eleven peptide-modified compounds was synthesized, showing promising results in delivering genetic materials. The purpose of this work is to elucidate the tandem mass spectrometric (MS/MS) dissociation behaviour of these novel molecules establishing a generalized MS/MS fingerprint. Exact mass measurements were achieved using a hybrid quadrupole orthogonal time-of-flight mass spectrometer (QqToF-MS) and a multi-stage tandem mass spectrometric analysis was conducted using a triple quadrupole-linear ion trap mass spectrometer (QqQLIT-MS)...
April 14, 2017: Journal of Mass Spectrometry: JMS
Zhaoyu Zheng, Julius Pavlov, Athula B Attygalle
In the past, Chrome Yellow (lead chromate, PbCrO4 ), a bright orange-red substance, has been widely used as an inorganic pigment in the production of paints, coatings, and plastics. Herein, we demonstrate that laser desorption/ionization mass spectrometry (LDI-MS) is a powerful tool for the detection of lead chromate in solid residues. In fact, lead chromate in trace amounts is easily detectable by LDI-MS even from residues left as latent prints. For example, a latent print obtained by stamping the exposed laterally cut surface of a pencil over 50 years old on an acetonitrile-moistened paper, was successfully imaged for both lead and chromate using a Synapt G2 HDMS mass spectrometer...
March 21, 2017: Journal of Mass Spectrometry: JMS
Raeuf Roushangar, George I Mias
MathIOmica-MSViewer is an add-on graphical user interface utility for the Mathematica software system which facilitates the visualization and exploration of spectra from open format mass spectrometry files (mzXML and mzML standard community formats). The viewer was designed for simplicity and handling of large mass spectrometry data files. To facilitate searches, users may use search filters for the spectra based on mass to charge ratios and retention times, and visualize precursor spectra associated to a parent spectrum...
March 15, 2017: Journal of Mass Spectrometry: JMS
Hongyan Liu, Yimin Wei, Hai Lu, Shuai Wei, Tao Jiang, Yingquan Zhang, Jinfu Ban, Boli Guo
RATIONALE: As (87) Sr/(86) Sr ratio plays a significant role in authenticating the geographical origin of foodstuff, it is important to identify where the (87) Sr/(86) Sr signature in food comes from, and the methods of (87) Sr/(86) Sr ratio analysis in food and environmental samples. METHODS: Wheat with three genotypes, soil and groundwater samples were collected from three regions of China during harvest time of 2014. The (87) Sr/(86) Sr ratios in the samples were determined by thermal ionization mass spectrometer in order to investigate the possible source of (87) Sr/(86) Sr in wheat, and the concentrations of Rb and Sr in wheat and soils were also detected by inductively coupled plasma mass spectrometry and combined with (87) Sr/(86) Sr ratio in order to trace the geographical origin of wheat...
March 14, 2017: Journal of Mass Spectrometry: JMS
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"