The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Richard D Smith - One of the best experts on this subject based on the ideXlab platform.
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lipid and glycolipid isomer analyses using ultra high resolutIon Ion Mobility Spectrometry separatIons
International Journal of Molecular Sciences, 2017Co-Authors: Roza Wojcik, Sandilya V. B. Garimella, Spencer A. Prost, Yehia M. Ibrahim, Erin S. Baker, Ian K Webb, Liulin Deng, Richard D SmithAbstract:Understanding the biological roles and mechanisms of lipids and glycolipids is challenging due to the vast number of possible isomers that may exist. Mass Spectrometry (MS) measurements are currently the dominant approach for studying and providing detailed informatIon on lipid and glycolipid presence and changes. However, difficulties in distinguishing the many structural isomers, due to the distinct lipid acyl chain positIons, double bond locatIons or specific glycan types, inhibit the delineatIon and assignment of their biological roles. Here we utilized ultra-high resolutIon Ion Mobility Spectrometry (IMS) separatIons by applying traveling waves in a serpentine multi-pass Structures for Lossless Ion ManipulatIons (SLIM) platform to enhance the separatIon of selected lipid and glycolipid isomers. The multi-pass arrangement allowed the investigatIon of paths ranging from ~16 m (one pass) to ~60 m (four passes) for the distinctIon of lipids and glycolipids with extremely small structural differences. These ultra-high resolutIon SLIM IMS-MS analyses provide a foundatIon for exploring and better understanding isomer-specific biological activities and disease processes.
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Development of an Ion Mobility Spectrometry-Orbitrap Mass Spectrometer Platform
Analytical chemistry, 2016Co-Authors: Yehia M. Ibrahim, Sandilya V. B. Garimella, Spencer A. Prost, Roza Wojcik, Randolph V. Norheim, Erin S. Baker, Ivan Rusyn, Richard D SmithAbstract:Complex samples benefit from multidimensIonal measurements where higher resolutIon enables more complete characterizatIon of biological and environmental systems. To address this challenge, we developed a drift tube-based Ion Mobility Spectrometry-Orbitrap mass spectrometer (IMS-Orbitrap MS) platform. To circumvent the time scale disparity between the fast IMS separatIon and the much slower Orbitrap MS acquisitIon, we utilized a dual gate and pseudorandom sequences to multiplex the injectIon of Ions and allow operatIon in signal averaging (SA), single multiplexing (SM), and double multiplexing (DM) IMS modes to optimize the signal-to-noise ratio of the measurements. For the SM measurements, a previously developed algorithm was used to reconstruct the IMS data. A new algorithm was developed for the DM analyses involving a two-step process that first recovers the SM data and then decodes the SM data. The algorithm also performs multiple refining procedures to minimize demultiplexing artifacts. The new IMS-O...
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high definitIon differential Ion Mobility Spectrometry with resolving power up to 500
Journal of the American Society for Mass Spectrometry, 2013Co-Authors: Alexandre A Shvartsburg, Randolph V. Norheim, Ronald J Moore, Thomas A Seim, William F Danielson, Gordon A Anderson, Richard D SmithAbstract:As the resolutIon of analytical methods improves, further progress tends to be increasingly limited by instrumental parameter instabilities that were previously inconsequential. This is now the case with differential Ion Mobility Spectrometry (FAIMS), where fluctuatIons of the voltages and gas pressure have become critical. A new high-definitIon generator for FAIMS compensatIon voltage reported here provides a stable and accurate output than can be scanned with negligible steps. This reduces the spectral drift and peak width, thus improving the resolving power (R) and resolutIon. The gain for multiply-charged peptides that have narrowest peaks is up to ~40 %, and R ~400–500 is achievable using He/N2 or H2/N2 gas mixtures.
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separatIon of a set of peptide sequence isomers using differential Ion Mobility Spectrometry
Analytical Chemistry, 2011Co-Authors: Alexandre A Shvartsburg, Andrew J Creese, Richard D Smith, Helen J CooperAbstract:Protein identificatIon in bottom-up proteomics requires disentangling isomers of proteolytic peptides, a major class of which are sequence inversIons. Their separatIon using Ion Mobility Spectrometry (IMS) has been limited to isomeric pairs. Here we demonstrate baseline separatIon of all seven 8-mer tryptic peptide isomers using differential IMS. EvaluatIon of peak capacity implies that even larger libraries should be resolved for heavier peptides with higher charge states.
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separatIon and classificatIon of lipids using differential Ion Mobility Spectrometry
Journal of the American Society for Mass Spectrometry, 2011Co-Authors: Alexandre A Shvartsburg, Richard D Smith, Giorgis Isaac, Nathalie Leveque, Thomas O MetzAbstract:CorrelatIons between the dimensIons of a 2-D separatIon create trend lines that depend on structural or chemical characteristics of the compound class and thus facilitate classificatIon of unknowns. This broadly applies to conventIonal Ion Mobility Spectrometry (IMS)/mass Spectrometry (MS), where the major biomolecular classes (e.g., lipids, peptides, nucleotides) occupy different trend line domains. However, strong correlatIon between the IMS and MS separatIons for Ions of same charge has impeded finer distinctIons. Differential IMS (or FAIMS) is generally less correlated to MS and thus could separate those domains better. We report the first observatIon of chemical class separatIon by trend lines using FAIMS, here for lipids. For lipids, FAIMS is indeed more independent of MS than conventIonal IMS, and subclasses (such as phospho-, glycero-, or sphingolipids) form distinct, often non-overlapping domains. Even finer categories with different functIonal groups or degrees of unsaturatIon are often separated. As expected, resolutIon improves in He-rich gases: at 70% He, glycerolipid isomers with different fatty acid positIons can be resolved. These results open the door for applicatIon of FAIMS to lipids, particularly in shotgun lipidomics and targeted analyses of bioactive lipids.
Alexandre A Shvartsburg - One of the best experts on this subject based on the ideXlab platform.
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high definitIon differential Ion Mobility Spectrometry with resolving power up to 500
Journal of the American Society for Mass Spectrometry, 2013Co-Authors: Alexandre A Shvartsburg, Randolph V. Norheim, Ronald J Moore, Thomas A Seim, William F Danielson, Gordon A Anderson, Richard D SmithAbstract:As the resolutIon of analytical methods improves, further progress tends to be increasingly limited by instrumental parameter instabilities that were previously inconsequential. This is now the case with differential Ion Mobility Spectrometry (FAIMS), where fluctuatIons of the voltages and gas pressure have become critical. A new high-definitIon generator for FAIMS compensatIon voltage reported here provides a stable and accurate output than can be scanned with negligible steps. This reduces the spectral drift and peak width, thus improving the resolving power (R) and resolutIon. The gain for multiply-charged peptides that have narrowest peaks is up to ~40 %, and R ~400–500 is achievable using He/N2 or H2/N2 gas mixtures.
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separatIon of a set of peptide sequence isomers using differential Ion Mobility Spectrometry
Analytical Chemistry, 2011Co-Authors: Alexandre A Shvartsburg, Andrew J Creese, Richard D Smith, Helen J CooperAbstract:Protein identificatIon in bottom-up proteomics requires disentangling isomers of proteolytic peptides, a major class of which are sequence inversIons. Their separatIon using Ion Mobility Spectrometry (IMS) has been limited to isomeric pairs. Here we demonstrate baseline separatIon of all seven 8-mer tryptic peptide isomers using differential IMS. EvaluatIon of peak capacity implies that even larger libraries should be resolved for heavier peptides with higher charge states.
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separatIon and classificatIon of lipids using differential Ion Mobility Spectrometry
Journal of the American Society for Mass Spectrometry, 2011Co-Authors: Alexandre A Shvartsburg, Richard D Smith, Giorgis Isaac, Nathalie Leveque, Thomas O MetzAbstract:CorrelatIons between the dimensIons of a 2-D separatIon create trend lines that depend on structural or chemical characteristics of the compound class and thus facilitate classificatIon of unknowns. This broadly applies to conventIonal Ion Mobility Spectrometry (IMS)/mass Spectrometry (MS), where the major biomolecular classes (e.g., lipids, peptides, nucleotides) occupy different trend line domains. However, strong correlatIon between the IMS and MS separatIons for Ions of same charge has impeded finer distinctIons. Differential IMS (or FAIMS) is generally less correlated to MS and thus could separate those domains better. We report the first observatIon of chemical class separatIon by trend lines using FAIMS, here for lipids. For lipids, FAIMS is indeed more independent of MS than conventIonal IMS, and subclasses (such as phospho-, glycero-, or sphingolipids) form distinct, often non-overlapping domains. Even finer categories with different functIonal groups or degrees of unsaturatIon are often separated. As expected, resolutIon improves in He-rich gases: at 70% He, glycerolipid isomers with different fatty acid positIons can be resolved. These results open the door for applicatIon of FAIMS to lipids, particularly in shotgun lipidomics and targeted analyses of bioactive lipids.
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ultrahigh resolutIon differential Ion Mobility Spectrometry using extended separatIon times
Analytical Chemistry, 2011Co-Authors: Alexandre A Shvartsburg, Richard D SmithAbstract:Ion Mobility Spectrometry (IMS), and particularly differential IMS or field asymmetric waveform IMS (FAIMS), is emerging as a versatile tool for separatIon and identificatIon of gas-phase Ions, especially in conjunctIon with mass Spectrometry. For over two decades since its inceptIon, the utility of FAIMS was constrained by resolving power (R) of less than ∼20. Stronger electric fields and optimized gas mixtures have recently raised achievable R to ∼200, but further progress with such approaches is impeded by electrical breakdown. However, the resolving power of planar FAIMS devices using any gas and field intensity scales as the square root of separatIon time (t). Here, we extended t from the previous maximum of 0.2 s up to 4-fold by reducing the carrier gas flow and increased the resolving power by up to 2-fold as predicted, to >300 for multiply charged peptides. The resulting resolutIon gain has enabled separatIon of previously “co-eluting” peptide isomers, including folding conformers and localizatIon...
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separatIon of peptide isomers with variant modified sites by high resolutIon differential Ion Mobility Spectrometry
Analytical Chemistry, 2010Co-Authors: Alexandre A Shvartsburg, Andrew J Creese, Richard D Smith, Helen J CooperAbstract:Many proteins and proteolytic peptides incorporate the same post-translatIonal modificatIon (PTM) at different sites, creating multiple localizatIon variants with different functIons or activities that may coexist in cells. Current analytical methods based on liquid chromatography (LC) followed by tandem mass Spectrometry (MS/MS) are challenged by such isomers that often coelute in LC and/or produce nonunique fragment Ions. The applicatIon of Ion Mobility Spectrometry (IMS) was explored, but success has been limited by insufficient resolutIon. We show that high-resolutIon differential Ion Mobility Spectrometry (FAIMS) employing helium-rich gases can readily separate phosphopeptides with variant modificatIon sites. Use of He/N2 mixtures containing up to 74% He has allowed separating to >95% three monophosphorylated peptides of identical sequence. Similar separatIon was achieved at 50% He, using an elevated electric field. Bisphosphorylated isomers that differ in only one modificatIon site were separated to...
Helen J Cooper - One of the best experts on this subject based on the ideXlab platform.
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Data to accompany "Structural analysis of 14-3-3- derived phosphopeptides using electron capture dissociatIon mass Spectrometry, travelling wave Ion Mobility Spectrometry and molecular modelling"
2020Co-Authors: Helen J CooperAbstract:Data to accompany "Structural analysis of 14-3-3- derived phosphopeptides using electron capture dissociatIon mass Spectrometry, travelling wave Ion Mobility Spectrometry and molecular modelling"
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separatIon and identificatIon of isomeric glycopeptides by high field asymmetric waveform Ion Mobility Spectrometry
Analytical Chemistry, 2012Co-Authors: Andrew J Creese, Helen J CooperAbstract:The analysis of intact glycopeptides by mass Spectrometry is challenging due to the numerous possibilities for isomerizatIon, both within the attached glycan and the locatIon of the modificatIon on the peptide backbone. Here, we demonstrate that high field asymmetric wave Ion Mobility Spectrometry (FAIMS), also known as differential Ion Mobility, is able to separate isomeric O-linked glycopeptides that have identical sequences but differing sites of glycosylatIon. Two glycopeptides from the glycoprotein mucin 5AC, GT(GalNAc)TPSPVPTTSTTSAP and GTTPSPVPTTST(GalNAc)TSAP (where GalNAc is O-linked N-acetylgalactosamine), were shown to coelute following reversed-phase liquid chromatography. However, FAIMS analysis of the glycopeptides revealed that the compensatIon voltage ranges in which the peptides were transmitted differed. Thus, it is possible at certain compensatIon voltages to completely separate the glycopeptides. SeparatIon of the glycopeptides was confirmed by unique reporter Ions produced by suppleme...
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separatIon of a set of peptide sequence isomers using differential Ion Mobility Spectrometry
Analytical Chemistry, 2011Co-Authors: Alexandre A Shvartsburg, Andrew J Creese, Richard D Smith, Helen J CooperAbstract:Protein identificatIon in bottom-up proteomics requires disentangling isomers of proteolytic peptides, a major class of which are sequence inversIons. Their separatIon using Ion Mobility Spectrometry (IMS) has been limited to isomeric pairs. Here we demonstrate baseline separatIon of all seven 8-mer tryptic peptide isomers using differential IMS. EvaluatIon of peak capacity implies that even larger libraries should be resolved for heavier peptides with higher charge states.
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separatIon of peptide isomers with variant modified sites by high resolutIon differential Ion Mobility Spectrometry
Analytical Chemistry, 2010Co-Authors: Alexandre A Shvartsburg, Andrew J Creese, Richard D Smith, Helen J CooperAbstract:Many proteins and proteolytic peptides incorporate the same post-translatIonal modificatIon (PTM) at different sites, creating multiple localizatIon variants with different functIons or activities that may coexist in cells. Current analytical methods based on liquid chromatography (LC) followed by tandem mass Spectrometry (MS/MS) are challenged by such isomers that often coelute in LC and/or produce nonunique fragment Ions. The applicatIon of Ion Mobility Spectrometry (IMS) was explored, but success has been limited by insufficient resolutIon. We show that high-resolutIon differential Ion Mobility Spectrometry (FAIMS) employing helium-rich gases can readily separate phosphopeptides with variant modificatIon sites. Use of He/N2 mixtures containing up to 74% He has allowed separating to >95% three monophosphorylated peptides of identical sequence. Similar separatIon was achieved at 50% He, using an elevated electric field. Bisphosphorylated isomers that differ in only one modificatIon site were separated to...
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separatIon of peptide isomers with variant modified sites by high resolutIon differential Ion Mobility Spectrometry
Analytical Chemistry, 2010Co-Authors: Alexandre A Shvartsburg, Andrew J Creese, Richard D Smith, Helen J CooperAbstract:Many proteins and proteolytic peptides incorporate the same post-translatIonal modificatIon (PTM) at different sites, creating multiple localizatIon variants with different functIons or activities that may coexist in cells. Current analytical methods based on liquid chromatography (LC) followed by tandem mass Spectrometry (MS/MS) are challenged by such isomers that often coelute in LC and/or produce nonunique fragment Ions. The applicatIon of Ion Mobility Spectrometry (IMS) was explored, but success has been limited by insufficient resolutIon. We show that high-resolutIon differential Ion Mobility Spectrometry (FAIMS) employing helium-rich gases can readily separate phosphopeptides with variant modificatIon sites. Use of He/N(2) mixtures containing up to 74% He has allowed separating to >95% three monophosphorylated peptides of identical sequence. Similar separatIon was achieved at 50% He, using an elevated electric field. Bisphosphorylated isomers that differ in only one modificatIon site were separated to the same extent. We anticipate FAIMS capabilities for such separatIons to extend to other PTMs.
Mika Sillanpaa - One of the best experts on this subject based on the ideXlab platform.
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determinatIon of chlorophenols in water by headspace solid phase microextractIon Ion Mobility Spectrometry hs spme ims
Talanta, 2013Co-Authors: Sanna Holopainen, Ville Luukkonen, Marjaana Nousiainen, Mika SillanpaaAbstract:Abstract Chlorophenols (CPs) as persistent toxic compounds are of worldwide environmental concern. Usage of chlorinated phenols, especially pentachlorophenol (PCP), has been restricted or widely banned in many countries due to their possible adverse health effects even at low concentratIons. Ion Mobility Spectrometry (IMS) has received increasing interest in environmental applicatIons due to its unique characteristics, such as portability and speed of analysis. A range of sample introductIon methods combined with IMS enable analysis from different environmental matrices. This study utilised headspace solid phase microextractIon IMS (HS-SPME-IMS) in the determinatIon of CPs from water samples. The extractIon conditIons were examined and the method was applied to real water samples. The developed method is suitable to detect CPs at milligram per liter level in water. Based on the results, SPME-IMS setup is feasible as an early warning system for water monitoring of pollutants present in drinking or surface water in case of environmental accidents or leakages.
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Ion Mobility Spectrometry and its applicatIons in detectIon of chemical warfare agents
Analytical Chemistry, 2010Co-Authors: Marko Makinen, Osmo Anttalainen, Mika SillanpaaAbstract:When fast detectIon of chemical warfare agents in the field is required, the Ion Mobility spectrometer may be the only suitable optIon. This article provides an essential survey of the different Ion Mobility Spectrometry detectIon technologies. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.)
Yan Hong - One of the best experts on this subject based on the ideXlab platform.
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normal inverse bimodule operatIon hadamard transform Ion Mobility Spectrometry
Analytica Chimica Acta, 2018Co-Authors: Yan Hong, Chaoqun Huang, Sheng Liu, Lei Xia, Chengyin Shen, Yannan ChuAbstract:In order to suppress or eliminate the spurious peaks and improve signal-to-noise ratio (SNR) of Hadamard transform Ion Mobility Spectrometry (HT-IMS), a normal-inverse bimodule operatIon Hadamard transform - Ion Mobility Spectrometry (NIBOHT-IMS) technique was developed. In this novel technique, a normal and inverse pseudo random binary sequence (PRBS) was produced in sequential order by an Ion gate controller and utilized to control the Ion gate of IMS, and then the normal HT-IMS Mobility spectrum and the inverse HT-IMS Mobility spectrum were obtained. A NIBOHT-IMS Mobility spectrum was gained by subtracting the inverse HT-IMS Mobility spectrum from normal HT-IMS Mobility spectrum. Experimental results demonstrate that the NIBOHT-IMS technique can significantly suppress or eliminate the spurious peaks, and enhance the SNR by measuring the reactant Ions. Furthermore, the gas CHCl3 and CH2Br2 were measured for evaluating the capability of detecting real sample. The results show that the NIBOHT-IMS technique is able to eliminate the spurious peaks and improve the SNR notably not only for the detectIon of larger Ion signals but also for the detectIon of small Ion signals.
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simultaneous improvement of resolving power and signal to noise ratio using a modified hadamard transform inverse Ion Mobility Spectrometry technique
Journal of the American Society for Mass Spectrometry, 2017Co-Authors: Yan Hong, Chaoqun Huang, Sheng Liu, Lei Xia, Chengyin Shen, Haihe Jiang, Yannan ChuAbstract:In order to improve the resolving power (RP) and signal-to-noise ratio (SNR) of Ion Mobility Spectrometry (IMS) simultaneously, a modified Hadamard transform-inverse Ion Mobility Spectrometry (MHT-IIMS) technique was developed. In this novel technique, a series of isolating codes were appended to each element of the pseudo random binary sequence (PRBS), and then the modified modulatIon sequence was formed and used to control the Ion gate of the inverse IMS (IIMS). Experimental results demonstrate that the MHT-IIMS technique can significantly enhance the resolving power and SNR simultaneously by measuring the spectra of reactIon Ions. Furthermore, the gas sample CCl4 and CHCl3 were measured for evaluating the capability of detecting those samples which have single and multiple product Ions. The results show that this novel technique is able to simultaneously improve the resolving power and SNR notablely for the real sample detectIon without any significant instrumental changes.
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rapid identificatIon of false peaks in the spectrum of hadamard transform Ion Mobility Spectrometry with inverse gating technique
RSC Advances, 2015Co-Authors: Yan Hong, Chaoqun Huang, Lei Xia, Chengyin Shen, Wenqi Niu, Hui Gao, Haihe JiangAbstract:With the applicatIon of Hadamard transform (HT) technique, the signal to noise ratio of Ion Mobility Spectrometry (IMS) has been improved significantly. Nevertheless, possibly due to the modulatIon defects, false peaks appear in the demultiplexed data and demonstrate similar features to those of the real signal peaks, which makes them hard to be discriminated. Facing this challenge, a novel method has been presented in this work and achieved the rapid identificatIon of the false peaks in Hadamard multiplexing IMS. Simply by introducing the inverse gating technique to Hadamard multiplexing, the novel inverse Hadamard transform (IHT) method is developed. With the applicatIon of this novel method in IMS, most of the false peaks are changed to opposite to the real signal peaks, which makes them easy to be classified as the false peaks. Furthermore, with the help of the single “code” extended method, the amount of the false peaks in inverse Hadamard transform Ion Mobility Spectrometry (IHT-IMS) decreases dramatically, and this makes the identificatIon more accurate. The sample tests further demonstrate that the inverse Hadamard transform (IHT) method is an effective way to address the problem of rapid identificatIon of the false peaks and upgrade the quality analysis of Hadamard multiplexing Ion Mobility Spectrometry.
