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Ion mobility spectrometry

Juan Camilo Molano-Arevalo, Kevin Jeanne Dit Fouque, Khoa N Pham, Jaroslava Miksovska, Mark E Ridgeway, Melvin A Park, Francisco Fernandez-Lima
Globular proteins, such as cytochrome c (cyt c), display an organized native conformation, maintained by a hydrogen bond interaction network. In the present work, the structural interrogation of kinetically trapped intermediates of cyt c was performed by correlating the ion-neutral collision cross section (CCS) and charge state with the starting solution conditions and time after desolvation using collision induced activation (CIA), time resolved hydrogen/deuterium back exchange (HDX) and trapped ion mobility spectrometry - mass spectrometry (TIMS-MS)...
July 25, 2017: Analytical Chemistry
Danny Fisher, Raya Zach, Yossef Matana, Paz Elia, Shiran Shustack, Yarden Sharon, Yehuda Zeiri
The marked increase in international terror in recent years requires the development of highly efficient methods to detect trace amounts of explosives at airports, border crossings and check points. The preferred analytical method worldwide is the ion mobility spectrometry (IMS) that is capable of detecting most explosives at the nano-gram level. Sample collection for the IMS analysis is based on swabbing of a passenger's belongings to collect possible explosive residues. The present study examines a wide range of issues related to swab-based particle collection and analysis, in the hope of gaining deeper understanding into this technique that will serve to improve the detection process...
November 1, 2017: Talanta
Ileana Andreea Ratiu, Victor Bocos-Bintintan, Adrian Patrut, Victor Hugo Moll, Matthew Turner, C L Paul Thomas
The objective of our study was to investigate whether one may quickly and reliably discriminate different microorganism strains by direct monitoring of the headspace atmosphere above their cultures. Headspace samples above a series of in vitro bacterial cultures were directly interrogated using an aspiration type ion mobility spectrometer (a-IMS), which produced distinct profiles ("fingerprints") of ion currents generated simultaneously by the detectors present inside the ion mobility cell. Data processing and analysis using principal component analysis showed net differences in the responses produced by volatiles emitted by various bacterial strains...
August 22, 2017: Analytica Chimica Acta
Paul D Rainville, Ian D Wilson, Jeremy K Nicholson, Giorgis Issacs, Lauren Mullin, James I Langridge, Robert S Plumb
The need for rapid and efficient high throughput metabolic phenotyping (metabotyping) in metabolomic/metabonomic studies often requires compromises to be made between analytical speed and metabolome coverage. Here the effect of column length (150, 75 and 30 mm) and gradient duration (15, 7.5 and 3 min respectively) on the number of features detected when untargeted metabolic profiling of human urine using reversed-phase gradient ultra performance chromatography with, and without, ion mobility spectrometry, has been examined...
August 22, 2017: Analytica Chimica Acta
Yang Kang, Bradley B Schneider, Thomas R Covey
Sample throughput in electrospray ionization mass spectrometry (ESI-MS) is limited by the need for frequent ion path cleaning to remove accumulated debris that can lead to charging and general performance degradation. Contamination of ion optics within the vacuum system is particularly problematic as routine cleaning requires additional time for cycling the vacuum pumps. Differential mobility spectrometry (DMS) can select targeted ion species for transmission, thereby reducing the total number of charged particles entering the vacuum system...
July 21, 2017: Journal of the American Society for Mass Spectrometry
Anupriya, Elaura Gustafson, Daniel N Mortensen, David V Dearden
Two corrections to the equation used in the cross-sectional areas by Fourier transform ion cyclotron resonance ("CRAFTI") technique are identified. In CRAFTI, ion collision cross-sections are obtained from the pressure-dependent ion linewidths in Fourier transform mass spectra. The effects of these corrections on the accuracy of the cross-sections obtained using the CRAFTI technique are evaluated experimentally using the 20 biogenic amino acids and several crown ether complexes with protonated alkyl monoamines...
July 21, 2017: Journal of the American Society for Mass Spectrometry
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
James N Bull, Neville J A Coughlan, Evan John Bieske
The utility of tandem ion mobility mass spectrometry coupled with electronic spectroscopy to investigate protomer-specific photochemistry is demonstrated by measuring the photoisomerization response for protomers of protonated 4-dicyanomethylene-2-methyl-6-para-dimethylaminostyryl-4H-pyran (DCM) molecules. The target DCMH(+) species, has three protomers that are distinguished by their different collision cross-sections with He, N2, and CO2 buffer gases, trends in abundance with ion source conditions, and from their photoisomerization responses...
July 19, 2017: Journal of Physical Chemistry. A
Mathilde Farenc, Benoit Paupy, Sabrina Marceau, Eleanor Riches, Carlos Afonso, Pierre Giusti
Ion mobility coupled with mass spectrometry was proven to be an efficient way to characterize complex mixtures such as petroleum samples. However, the identification of isomeric species is difficult owing to the molecular complexity of petroleum and no availability of standard molecules. This paper proposes a new simple indicator to estimate the isomeric content of highly complex mixtures. This indicator is based on the full width at half maximum (FWHM) of the extracted ion mobility peak measured in millisecond or square angstrom that is corrected for instrumental factors such as ion diffusion...
July 18, 2017: Journal of the American Society for Mass Spectrometry
David J Cocovi-Solberg, Francesc A Esteve-Turrillas, Sergio Armenta, Miguel de la Guardia, Manuel Miró
A lab-on-valve miniaturized system integrating on-line disposable micro-solid phase extraction has been interfaced with ion mobility spectrometry for the accurate and sensitive determination of cocaine and ecgonine methyl ester in oral fluids. The method is based on the automatic loading of 500μL of oral fluid along with the retention of target analytes and matrix clean-up by mixed-mode cationic/reversed-phase solid phase beads, followed by elution with 100μL of 2-propanol containing (3% v/v) ammonia, which are online injected into the IMS...
June 30, 2017: Journal of Chromatography. A
Christian Lipok, Jörg Hippler, Oliver J Schmitz
A two-dimensional GC (2D-GC) method was developed and coupled to an ion mobility-high resolution mass spectrometer, which enables the separation of complex samples in four dimensions (2D-GC, ion mobilility spectrometry and mass spectrometry). This approach works as a continuous multiheart-cutting GC-system (GC+GC), using a long modulation time of 20s, which allows the complete transfer of most of the first dimension peaks to the second dimension column without fractionation, in comparison to comprehensive two-dimensional gas chromatography (GCxGC)...
July 8, 2017: Journal of Chromatography. A
Felix Maurer, Larissa Walter, Martin Geiger, Jörg Ingo Baumbach, Daniel I Sessler, Thomas Volk, Sascha Kreuer
Propofol is a commonly used intravenous general anesthetic. Multi-capillary column (MCC) coupled Ion-mobility spectrometry (IMS) can be used to quantify exhaled propofol, and thus estimate plasma drug concentration. Here, we present results of the calibration and analytical validation of a MCC/IMS pre-market prototype for propofol quantification in exhaled air. Calibration with a reference gas generator yielded an R(2)≥0.99 with a linear array for the calibration curve from 0 to 20 ppbv. The limit of quantification was 0...
July 1, 2017: Journal of Pharmaceutical and Biomedical Analysis
Ryoichi Moriyama, Ryuki Sato, Motoyoshi Nakano, Keijiro Ohshimo, Fuminori Misaizu
Structural assignments of gas phase chromium oxide cluster anions, CrmOn(-) (m = 1-7), have been achieved by comparison between experimental collision cross sections measured by ion mobility mass spectrometry and theoretical collision cross sections of optimized structures by quantum chemical calculations. In the mass spectrum, significant magic behavior between the numbers m and n was not observed for CrmOn(-), while wide ranges of compositions were observed around CrmO2m+2(-) to (CrO3)m(-) as reported previously...
July 13, 2017: Journal of Physical Chemistry. A
Fredrik Haeffner, Karl K Irikura
Collision-induced dissociation (or tandem mass spectrometry, MS/MS) of a protonated peptide results in a spectrum of fragment ions that is useful for inferring amino acid sequence. This is now commonplace and a foundation of proteomics. The underlying chemical and physical processes are believed to be those familiar from physical organic chemistry and chemical kinetics. However, first-principles predictions remain intractable because of the conflicting necessities for high accuracy (to achieve qualitatively correct kinetics) and computational speed (to compensate for the high cost of reliable calculations on such large molecules)...
July 11, 2017: Journal of the American Society for Mass Spectrometry
Eric T Dziekonski, Joshua T Johnson, Kenneth W Lee, Scott A McLuckey
Collision cross sections (CCSs) were determined from the frequency-domain linewidths in a Fourier transform electrostatic linear ion trap. With use of an ultrahigh-vacuum precision leak valve and nitrogen gas, transients were recorded as the background pressure in the mass analyzer chamber was varied between 4× 10(-8) and 7 × 10(-7) Torr. The energetic hard-sphere ion-neutral collision model, described by Xu and coworkers, was used to relate the recorded image charge to the CCS of the molecule. In lieu of our monoisotopically isolating the mass of interest, the known relative isotopic abundances were programmed into the Lorentzian fitting algorithm such that the linewidth was extracted from a sum of Lorentzians...
July 11, 2017: Journal of the American Society for Mass Spectrometry
Sara Tengattini, Elena Domínguez-Vega, Caterina Temporini, Teodora Bavaro, Francesca Rinaldi, Luciano Piubelli, Loredano Pollegioni, Gabriella Massolini, Govert W Somsen
Improved methods for detailed characterization of complex glycoproteins are required in the growing sector of biopharmaceuticals. Hydrophilic interaction liquid chromatography (HILIC) coupled to high resolution (HR) time-of-flight mass spectrometric (TOF-MS) detection was examined for the characterization of intact neo-glycoproteins prepared by chemical conjugation of synthetic saccharides to the lysine residues of selected recombinant proteins. The separation performances of three different amide HILIC columns (TSKgel Amide-80, XBridge BEH and AdvanceBio Glycan Mapping) were tested...
August 15, 2017: Analytica Chimica Acta
Lucie Borovcová, Martina Hermannová, Volodymyr Pauk, Matěj Šimek, Vladimír Havlíček, Karel Lemr
Coupling of ion mobility with mass spectrometry has brought new frontiers in separation and quantitation of a wide range of isobaric/isomeric compounds. Ion mobility spectrometry may separate ions possessing the identical molecular formula but having different molecular shapes. The separation space in most commercially available instruments is limited and rarely the mobility resolving power exceeds one hundred. From this perspective, new approaches allowing for extracting individual compound signals out of a more complex mixture are needed...
August 15, 2017: Analytica Chimica Acta
Xiangying Yu, Zhong-Ping Yao
In this study, travelling wave ion mobility mass spectrometry has been used to investigate chiral differentiation of common chiral amino acids, through separation of binuclear copper bound tetrameric ions formed with chiral selector tryptophan, proline, tyrosine, phenylalanine or histidine. Significant chiral recognition was observed for amino acids with aromatic rings or long and active side chains, with peak-to-peak resolutions up to 1.826. Tryptophan and histidine offered better enantioselectivity, compared to other chiral selectors...
August 15, 2017: Analytica Chimica Acta
Heping Sun, Qi Zhang, Zhi Zhang, Jin Tong, Dafeng Chu, Jingkai Gu
PEGylation is practically one of most important modifications of drugs including small molecules, peptides and proteins, which has been proven to dramatically improve physicochemical properties and pharmacokinetic behavior of the PEGylated drugs. However, it is a challenge currently to quantitatively analyze PEG and PEGylated drugs by various analytical methods, even mass spectrometry because of multiple parent ion distribution of PEG caused by its polydispersity of molecular weight. Here we developed a robust method with MS/MS(ALL) technique using electrospray ionization (ESI) source coupled high resolution Quadrupole Time-of-Flight (Q-TOF) mass spectrometry for the quantification of PEG2K-Paclitaxel (PEG-PTX) and its two metabolites, PEG and Paclitaxel (PTX)...
June 23, 2017: Journal of Pharmaceutical and Biomedical Analysis
Jian Wang, Yu Xu, Yunfeng Zhang, Hong Wang, Weihui Zhong
RATIONALE: Seven unknown antibiotic impurities in cefonicid sodium were separated and characterized by a trap-free two-dimensional liquid chromatography coupled to high resolution ion trap/time-of-flight mass spectrometry s2D LC-IT-TOF MS) with positive and negative modes of electrospray ionization method. Trap-free two-dimensional liquid chromatography and online demineralization technique made it possible to characterize cefonicid sodium in the condition of the official standard, and the TIC chromatogram of LC-MS was in conformity with the LC chromatogram of the official analytical method in the peak sequence of impurities...
July 8, 2017: Rapid Communications in Mass Spectrometry: RCM
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