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Poad BLJ, Young RSE, Marshall DL, Trevitt AJ, Blanksby SJ. Accelerating Ozonolysis Reactions Using Supplemental RF-Activation of Ions in a Linear Ion Trap Mass Spectrometer. Anal Chem 2022; 94:3897-3903. [PMID: 35201768 DOI: 10.1021/acs.analchem.1c04915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gas-phase ion-molecule reactions provide structural insights across a range of analytical applications. A hindrance to the wider use of ion-molecule reactions is that they are relatively slow compared to other ion activation modalities and can thereby impose a bottleneck on the time required to analyze each sample. Here we describe a method for accelerating the rate of ion-molecule reactions involving ozone, implemented by supplementary RF-activation of mass-selected ions within a linear ion trap. Reaction rate accelerations between 15-fold (for ozonolysis of alkenes in ionised lipids) and 90-fold (for ozonation of halide anions) are observed compared to thermal conditions. These enhanced reaction rates with ozone increase sample throughput, aligning the reaction time with the overall duty cycle of the mass spectrometer. We demonstrate that the acceleration is due to the supplementary RF-activation surmounting the activation barrier energy of the entrance channel of the ion-molecule reaction. This rate acceleration is subsequently shown to aid identification of new, low abundance lipid isomers and enables an equivalent increase in the number of lipid species that can be analyzed.
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Affiliation(s)
- Berwyck L J Poad
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4001, Australia.,Central Analytical Research Facility, Queensland University of Technology, Brisbane, Queensland 4001, Australia
| | - Reuben S E Young
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4001, Australia
| | - David L Marshall
- Central Analytical Research Facility, Queensland University of Technology, Brisbane, Queensland 4001, Australia
| | - Adam J Trevitt
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2552, Australia
| | - Stephen J Blanksby
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4001, Australia.,Central Analytical Research Facility, Queensland University of Technology, Brisbane, Queensland 4001, Australia
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2
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Snyder DT, Szalwinski LJ, Pilo AL, Jarrah NK, Cooks RG. Selective Gas-Phase Mass Tagging via Ion/Molecule Reactions Combined with Single Analyzer Neutral Loss Scans to Probe Pharmaceutical Mixtures. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1092-1101. [PMID: 30887460 DOI: 10.1007/s13361-019-02149-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 06/09/2023]
Abstract
We have demonstrated the use of a simple single ion trap mass spectrometer to identify classes of compounds as well as individual components in complex mixtures. First, a neutral reagent was used to mass tag oxygen-containing analytes using a gas-phase ion/molecule reaction. Then, a neutral loss scan was used to indicate the carboxylic acids. The lack of unit mass selectivity in the neutral loss scan required subsequent product ion scans to confirm the presence and identity of the individual carboxylic acids. The neutral loss scan technique reduced the number of data-dependent MS/MS scans required to confirm identification of signals as protonated carboxylic acids. The method was demonstrated on neat mixtures of standard carboxylic acids as well as on solutions of relevant pharmaceutical tablets and may be generalizable to other ion/molecule reactions.
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Affiliation(s)
- Dalton T Snyder
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Lucas J Szalwinski
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Alice L Pilo
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Nina K Jarrah
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - R Graham Cooks
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA.
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Czar MF, Marchand A, Zenobi R. A Modified Traveling Wave Ion Mobility Mass Spectrometer as a Versatile Platform for Gas-Phase Ion-Molecule Reactions. Anal Chem 2019; 91:6624-6631. [PMID: 31008583 DOI: 10.1021/acs.analchem.9b00541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Taken individually, chemical labeling and mass spectrometry are two well-established tools for the structural characterization of biomolecular complexes. A way to combine their respective advantages is to perform gas-phase ion-molecule reactions (IMRs) inside the mass spectrometer. This is, however, not so well developed because of the limited range of usable chemicals and the lack of commercially available IMR devices. Here, we modified a traveling wave ion mobility mass spectrometer to enable IMRs in the trapping region of the instrument. Only one minor hardware modification is needed to allow vapors of a variety of liquid reagents to be leaked into the trap traveling wave ion guide of the instrument. A diverse set of IMRs can then readily be performed without any loss in instrument performance. We demonstrate the advantages of implementing IMR capabilities in general, and to this quadrupole-ion mobility-time-of-flight (Q-IM-TOF) mass spectrometer in particular, by exploiting the full functionality of the instrument, including mass selection, ion mobility separation, and post-mobility fragmentation. The potential to carry out gas-phase IMR kinetics experiments is also illustrated. We demonstrate the versatility of the setup using gas-phase IMRs of established utility for biological mass spectrometry, including hydrogen-deuterium exchange, ion-molecule proton transfer reactions, and covalent modification of DNA anions using trimethylsilyl chloride.
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Affiliation(s)
- Martin F Czar
- Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences , ETH Zurich , Zurich 8093 , Switzerland
| | - Adrien Marchand
- Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences , ETH Zurich , Zurich 8093 , Switzerland
| | - Renato Zenobi
- Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences , ETH Zurich , Zurich 8093 , Switzerland
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Zhu H, Ma X, Kong JY, Zhang M, Kenttämaa HI. Identification of Carboxylate, Phosphate, and Phenoxide Functionalities in Deprotonated Molecules Related to Drug Metabolites via Ion-Molecule Reactions with water and Diethylhydroxyborane. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2189-2200. [PMID: 28741125 DOI: 10.1007/s13361-017-1713-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 04/09/2017] [Accepted: 04/10/2017] [Indexed: 05/18/2023]
Abstract
Tandem mass spectrometry based on ion-molecule reactions has emerged as a powerful tool for structural elucidation of ionized analytes. However, most currently used reagents were designed to react with protonated analytes, making them suboptimal for acidic analytes that are preferentially detected in negative ion mode. In this work we demonstrate that the phenoxide, carboxylate, and phosphate functionalities can be identified in deprotonated molecules by use of a combination of two reagents, diethylmethoxyborane (DEMB) and water. A novel reagent introduction setup that allowed DEMB and water to be separately introduced into the ion trap region of the mass spectrometer was developed to facilitate fundamental studies of this reaction. A new reagent, diethylhydroxyborane (DEHB), was generated inside the ion trap by hydrolysis of DEMB on introduction of water. Most carboxylates and phenoxides formed a DEHB adduct, followed by addition of one water molecule and subsequent ethane elimination (DEHB adduct +H2O - CH3CH3) as the major product ion. Phenoxides with a hydroxy group adjacent to the deprotonation site and phosphates formed a DEHB adduct, followed by ethane elimination (DEHB adduct - CH3CH3). Deprotonated molecules with strong intramolecular hydrogen bonds or without the aforementioned functionalities, including sulfates, were unreactive toward DEHB/H2O. Reaction mechanisms were explored via isotope labeling experiments and quantum chemical calculations. The mass spectrometry method allowed the differentiation of phenoxide-, carboxylate-, phosphate-, and sulfate-containing analytes. Finally, it was successfully coupled with high-performance liquid chromatography for the analysis of a mixture containing hymecromone, a biliary spasm drug, and its three possible metabolites. Graphical Abstract ᅟ.
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Affiliation(s)
- Hanyu Zhu
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Xin Ma
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - John Y Kong
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
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Zhu H, Jarrell TM, Louden N, Max JP, Marcum CL, Luo H, Riedeman JS, Abu-Omar MM, Kenttämaa HI. Identification of the Phenol Functionality in Deprotonated Monomeric and Dimeric Lignin Degradation Products via Tandem Mass Spectrometry Based on Ion-Molecule Reactions with Diethylmethoxyborane. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1813-1823. [PMID: 27553243 DOI: 10.1007/s13361-016-1442-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 06/06/2023]
Abstract
Conversion of lignin into smaller molecules provides a promising alternate and sustainable source for the valuable chemicals currently derived from crude oil. Better understanding of the chemical composition of the resulting product mixtures is essential for the optimization of such conversion processes. However, these mixtures are complex and contain isomeric molecules with a wide variety of functionalities, which makes their characterization challenging. Tandem mass spectrometry based on ion-molecule reactions has proven to be a powerful tool in functional group identification and isomer differentiation for previously unknown compounds. This study demonstrates that the identification of the phenol functionality, the most commonly observed functionality in lignin degradation products, can be achieved via ion-molecule reactions between diethylmethoxyborane (DEMB) and the deprotonated analyte in the absence of strongly electron-withdrawing substituents in the ortho- and para-positions. Either a stable DEMB adduct or an adduct that has lost a methanol molecule (DEMB adduct-MeOH) is formed for these ions. Deprotonated phenols with an adjacent phenol or hydroxymethyl functionality or a conjugated carboxylic acid functionality can be identified based on the formation of DEMB adduct-MeOH. Deprotonated compounds not containing the phenol functionality and phenols containing an electron-withdrawing ortho- or para-substituent were found to be unreactive toward diethylmethoxyborane. Hence, certain deprotonated isomeric compounds with phenol and carboxylic acid, aldehyde, carboxylic acid ester, or nitro functionalities can be differentiated via these reactions. The above mass spectrometry method was successfully coupled with high-performance liquid chromatography for the analysis of a complex biomass degradation mixture. Graphical Abstract ᅟ.
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Affiliation(s)
- Hanyu Zhu
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | | | | | - Joann P Max
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | | | - Hao Luo
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | | | - Mahdi M Abu-Omar
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
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Lanucara F, Fornarini S, Eyers CE, Crestoni ME. Probing the exposure of the phosphate group in modified amino acids and peptides by ion-molecule reactions with triethoxyborane in Fourier transform ion cyclotron resonance mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:1107-1116. [PMID: 24711274 DOI: 10.1002/rcm.6884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 02/27/2014] [Accepted: 02/27/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE Intramolecular hydrogen bonds between a phosphate group and charged residues play a crucial role in the chemistry of phosphorylated peptides, driving the species to specific conformations and affecting the exposure of the phosphate moiety. The nature and extent of these interactions can be investigated by measuring the reactivity of phosphate groups toward selected substrates in the gas phase. METHODS We used Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry (MS) to perform a systematic study on the gas-phase ionic reactivity of phosphorylated amino acids and peptides with triethoxyborane (TEB). Ions of interest were generated by electrospray ionization (ESI), isolated in the cell of the FT-ICR mass spectrometer, and allowed to react with a stationary pressure of TEB. The temporal evolution of the reaction was monitored and thermal rate constants were derived. The structure of the ionic products was confirmed by Collision-Induced Dissociation (CID) tandem mass spectrometry (MS/MS). RESULTS TEB was found to react with the phosphate of protonated phosphorylated amino acids and peptides by an addition-elimination pathway. The kinetic efficiency of the reaction showed a positive correlation with the charge state of the reagent ion, suggesting the existence of charge-state-dependent exposure of the phosphate groups towards the incoming neutral during the reaction. Isomeric phosphorylated peptides, only differing for the position of the modified serine residue, showed markedly different kinetic efficiencies. CONCLUSIONS The ability of a phosphorylated species to react with TEB depends on the ease of access to the phosphate moiety in the corresponding gaseous ion. Measuring the kinetic efficiency of such reactions can represent a valuable tool to explore the accessibility of phosphate groups in biomolecules.
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Affiliation(s)
- Francesco Lanucara
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester, M1 7DN, UK; Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
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Piatkivskyi A, Pyatkivskyy Y, Hurt M, Ryzhov V. Utilisation of gas-phase ion-molecule reactions for differentiation between phospho- and sulfocarbohydrates. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2014; 20:177-183. [PMID: 24895778 DOI: 10.1255/ejms.1270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Gas-phase ion-molecule reactions of four boron-containing neutrals were explored as a means for differentiation between isobaric phospho- and sulfocarbohydrates. Phosphorylation and sulfation impose an addition of 80 Da to the molecular mass, so for low-resolution mass spectrometers compounds that have such modifications will appear at the same nominal mass-to-charge (m/z) ratio. However, the ions of these isobaric species behave differently in ion-molecule reactions. All four evaluated neutral molecules [trimethyl borate (TMB), triethyl borate (TEB), diethylmethoxyborane (DEMB) and diisopropoxymethylborane (DIPMB)] proved to be reactive towards phosphorylated sugars and unreactive towards sulfated carbohydrates. In addition, TMB and TEB were found suitable for distinguishing positional isomers of phosphorylated carbohydrates, while reactions with DEMB and DIPMB were successful in differentiating phosphorylated, sulfated and unmodified deprotonated sugars. Similar reactions in the positive ion mode (alkali cationised) were found to be less conclusive.
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Piatkivskyi A, Pyatkivskyy Y, Ryzhov V. Evaluation of various silicon-and boron-containing compounds for the detection of phosphorylation in peptides via gas-phase ion-molecule reactions. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2014; 20:337-344. [PMID: 25420346 DOI: 10.1255/ejms.1286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Gas-phase ion-molecule reactions [IMR] of various boron- and silicon-containing neutrals were investigated as a potential route for detecting phosphorylation within peptides in the negative ion mode. Trimethyl borate (TMB), triethyl borate (TEB) and N,O- Bis(trimethylsilyl)acetamide (TMSA), unlike diethylmethoxyborane (DEMB), diisopropoxymethylborane [DiPMB] and chlorotrimethylsi- Lane (TMSCIL], reacted differently if a phosphate moiety was present and thus are suitable to detect phosphorylation. During multistage collision-induced dissociation experiments of the reaction products of IMR with TMB and TEB, the [LSsF - 4H + B]- ion formed a modified y2 fragment allowing the phosphorylation site to be assigned, unlike reaction products of DEMB and DiPMB which lost both the phos- phoric acid and the boron-containing moiety.
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9
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Martin AR, Vasseur JJ, Smietana M. Boron and nucleic acid chemistries: merging the best of both worlds. Chem Soc Rev 2013; 42:5684-713. [DOI: 10.1039/c3cs60038f] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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10
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Affiliation(s)
- Sandra Osburn
- Department of Chemistry and Biochemistry and Center for Biochemical and Biophysical Studies, Northern Illinois University, DeKalb, Illinois 60115, USA
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Eismin RJ, Fu M, Yem S, Widjaja F, Kenttämaa HI. Identification of epoxide functionalities in protonated monofunctional analytes by using ion/molecule reactions and collision-activated dissociation in different ion trap tandem mass spectrometers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:12-22. [PMID: 22002227 DOI: 10.1007/s13361-011-0249-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 09/05/2011] [Accepted: 09/06/2011] [Indexed: 05/31/2023]
Abstract
A mass spectrometric method has been delineated for the identification of the epoxide functionalities in unknown monofunctional analytes. This method utilizes gas-phase ion/molecule reactions of protonated analytes with neutral trimethyl borate (TMB) followed by collision-activated dissociation (CAD) in an ion trapping mass spectrometer (tested for a Fourier-transform ion cyclotron resonance and a linear quadrupole ion trap). The ion/molecule reaction involves proton transfer from the protonated analyte to TMB, followed by addition of the analyte to TMB and elimination of methanol. Based on literature, this reaction allows the general identification of oxygen-containing analytes. Vinyl and phenyl epoxides can be differentiated from other oxygen-containing analytes, including other epoxides, based on the loss of a second methanol molecule upon CAD of the addition/methanol elimination product. The only other analytes found to undergo this elimination are some amides but they also lose O = B-R (R = group bound to carbonyl), which allows their identification. On the other hand, other epoxides can be differentiated from vinyl and phenyl epoxides and from other monofunctional analytes based on the loss of (CH(3)O)(2)BOH or formation of protonated (CH(3)O)(2)BOH upon CAD of the addition/methanol elimination product. For propylene oxide and 2,3-dimethyloxirane, the (CH(3)O)(2)BOH fragment is more basic than the hydrocarbon fragment, and the diagnostic ion (CH(3)O)(2)BOH (2) (+) is formed. These reactions involve opening of the epoxide ring. The only other analytes found to undergo (CH(3)O)(2)BOH elimination are carboxylic acids, but they can be differentiated from the rest based on several published ion/molecule reaction methods. Similar results were obtained in the Fourier-transform ion cyclotron resonance and linear quadrupole ion trap mass spectrometer.
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Affiliation(s)
- Ryan J Eismin
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
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Somuramasami J, Duan P, Amundson LM, Archibold E, Winger BE, Kenttämaa HI. Differentiation of protonated aromatic regioisomers related to lignin by reactions with trimethylborate in a Fourier transform ion cyclotron resonance mass spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:1040-1051. [PMID: 21953045 DOI: 10.1007/s13361-011-0099-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 02/01/2011] [Accepted: 02/01/2011] [Indexed: 05/31/2023]
Abstract
Several lignin model compounds were examined to test whether gas-phase ion-molecule reactions of trimethylborate (TMB) in a FTICR can be used to differentiate the ortho-, meta-, and para-isomers of protonated aromatic compounds, such as those formed during degradation of lignin. All three regioisomers could be differentiated for methoxyphenols and hydroxyphenols. However, only the differentiation of the ortho-isomer from the meta- and para-isomers was possible for hydroxyacetophenones and hydroxybenzoic acids. Consideration of the previously reported proton affinities at all basic sites in the isomeric hydroxyphenols, and the calculated proton affinities at all basic sites in the three methoxyphenol isomers, revealed that the proton affinities of the analytes relative to that of TMB play an important role in determining whether and how they react with TMB. The loss of two methanol molecules (instead of one) from the adducts formed with TMB either during ion-molecule reactions, or during sustained-off resonance irradiated collision-activated dissociation of the ion-molecule reaction products, revealed the presence of two functionalities in almost all the isomers. This finding supports earlier results suggesting that TMB can be used to count the functionalities in unknown oxygen-containing analytes.
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Habicht SC, Vinueza NR, Amundson LM, Kenttämaa HI. Comparison of functional group selective ion-molecule reactions of trimethyl borate in different ion trap mass spectrometers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:520-530. [PMID: 21472570 DOI: 10.1007/s13361-010-0050-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/09/2010] [Accepted: 12/09/2010] [Indexed: 05/30/2023]
Abstract
We report here a comparison of the use of diagnostic ion-molecule reactions for the identification of oxygen-containing functional groups in Fourier-transform ion cyclotron resonance (FTICR) and linear quadrupole ion trap (LQIT) mass spectrometers. The ultimate goal of this research is to be able to identify functionalities in previously unknown analytes by using many different types of mass spectrometers. Previous work has focused on the reactions of various boron reagents with protonated oxygen-containing analytes in FTICR mass spectrometers. By using a LQIT modified to allow the introduction of neutral reagents into the helium buffer gas, this methodology has been successfully implemented to this type of an ion trap instrument. The products obtained from the reactions of trimethyl borate (TMB) with various protonated analytes are compared for the two instruments. Finally, the ability to integrate these reactions into LC-MS experiments on the LQIT is demonstrated.
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Affiliation(s)
- Steve C Habicht
- Department of Chemistry, Purdue University, Brown Building, 560 Oval Drive, West Lafayette, IN 47906, USA
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Fu M, Duan P, Li S, Eismin RJ, Kenttämaa HI. An ion/molecule reaction for the identification of analytes with two basic functional groups. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2009; 20:1251-1262. [PMID: 19345113 DOI: 10.1016/j.jasms.2009.02.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 02/13/2009] [Accepted: 02/13/2009] [Indexed: 05/27/2023]
Abstract
A mass spectrometric method is presented for the identification of analytes with two basic functionalities and PA between 222 and 245 kcal/mol, including diamines. This method utilizes gas-phase ion-molecule reactions of protonated analytes with neutral 1,1-diethoxyethene (DEE) in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR). A variety of protonated mono-, bi-, and trifunctional analytes containing different functional groups, namely, amido, amino, N-oxide, hydroxy, carboxylic acid, keto, thio, thioether, alkene, phosphite, and phosphonate, were tested in the FT-ICR. The results demonstrate that basic protonated bifunctional compounds (PA between 222 and 245 kcal/mol) react selectively with DEE by forming a specific addition/elimination product ion (adduct - EtOH) (this product was also observed for lysine with three functionalities). The diagnostic reaction sequence involves proton transfer from the protonated analyte to the basic vinyl group in DEE, followed by addition of one of the functional groups of the analyte to the electrophilic alpha-carbon in protonated DEE. The next step involves proton transfer from this functionality to the other analyte functionality, followed by proton transfer to DEE and elimination of ethanol. Since the mechanism involves proton transfer between two functional groups of the analyte, the reaction does not occur for analytes where the two functionalities cannot be in close proximity (i.e., meta-phenylenediamine), and where no proton is available (i.e., dimethylaminoketone).
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Affiliation(s)
- Mingkun Fu
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
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15
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Pyatkivskyy Y, Ryzhov V. Coupling of ion-molecule reactions with liquid chromatography on a quadrupole ion trap mass spectrometer. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:1288-1294. [PMID: 18351715 DOI: 10.1002/rcm.3494] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report for the first time a coupling of gas-phase ion-molecule reactions with chromatographic separations on a quadrupole ion trap mass spectrometer. The interface was accomplished by using a pulsed valve for the introduction of a volatile neutral into the ion trap. The pulsed valve controller is synchronized with the mass spectrometer software. The setup requires some minor modifications to the vacuum system of the commercial quadrupole ion trap but most of the modifications are external to the mass spectrometer. Two applications of this interface are described: differentiation between two phosphoglucose positional isomers and detection of a phosphopeptide in a peptide mixture. Both applications are using the reactivity of trimethoxyborate towards a phosphate moiety in the negative ion mode. The detection of phosphopeptides hinges on our findings that non-phosphorylated peptide anions do not react with trimethoxyborate. This LC/MS detection can be easily visualized in terms of selected reaction monitoring.
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Affiliation(s)
- Yuriy Pyatkivskyy
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, USA
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16
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Jackson AU, Werner SR, Talaty N, Song Y, Campbell K, Cooks RG, Morgan JA. Targeted metabolomic analysis of Escherichia coli by desorption electrospray ionization and extractive electrospray ionization mass spectrometry. Anal Biochem 2008; 375:272-81. [DOI: 10.1016/j.ab.2008.01.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 01/06/2008] [Accepted: 01/06/2008] [Indexed: 10/22/2022]
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17
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Pepi F, Barone V, Cimino P, Ricci A. Gas-Phase Chemistry of Diphosphate Anions as a Tool To Investigate the Intrinsic Requirements of Phosphate Ester Enzymatic Reactions: The [M1M2HP2O7]− Ions. Chemistry 2007; 13:2096-108. [PMID: 17143922 DOI: 10.1002/chem.200601093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Experimental studies on gaseous inorganic phosphate ions are practically nonexistent, yet they can prove helpful for a better understanding of the mechanisms of phosphate ester enzymatic processes. The present contribution extends our previous investigations on the gas-phase ion chemistry of diphosphate species to the [M(1)M(2)HP(2)O(7)](-) ions where M(1) and M(2) are the same or different and correspond to the Li, Na, K, Cs, and Rb cations. The diphosphate ions are formed by electrospray ionization of 10(-4) M solutions of Na(5)P(3)O(10) in CH(3)CN/H(2)O (1/1) and MOH bases or M salts as a source of M(+) cations. The joint application of mass spectrometric techniques and quantum-mechanical calculations makes it possible to characterize the gaseous [M(1)M(2)HP(2)O(7)](-) ions as a mixed ionic population formed by two isomeric species: linear diphosphate anion coordinated to two M(+) cations (group I) and [PO(3)M(1)M(2)HPO(4)](-) clusters (group II). The relative gas-phase stabilities and activation barriers for the isomerization I-->II, which depend on the nature of the M(+) cations, highlight the electronic susceptibility of P-O-P bond breaking in the active site of enzymes. The previously unexplored gas-phase reactivity of [M(1)M(2)HP(2)O(7)](-) ions towards alcohols of different acidity was investigated by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR/MS). The reaction proceeds by addition of the alcohol molecule followed by elimination of a water molecule.
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Affiliation(s)
- Federico Pepi
- Dipartamento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma La Sapienza, Piazzale A. Moro 5, 00185 Rome, Italy
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Gronert S. Quadrupole ion trap studies of fundamental organic reactions. MASS SPECTROMETRY REVIEWS 2005; 24:100-120. [PMID: 15389862 DOI: 10.1002/mas.20008] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Over the past several decades, quadrupole ion traps have become important instruments in the study of gas phase ion/molecule reactions. As a part of this work, they have been employed in a number of studies focused on fundamental organic reaction mechanisms. In this review, the general features and limitations of quadrupole ion traps are discussed followed by a description of representative ion trap studies of organic reaction mechanisms such as substitution, elimination, and acyl transfer reactions.
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Affiliation(s)
- Scott Gronert
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, USA.
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Pepi F, Ricci A, Rosi M, Di Stefano M. Gaseous H5P2O8? Ions: A Theoretical and Experimental Study on the Hydrolysis and Synthesis of Diphosphate Ion. Chemistry 2004; 10:5706-16. [PMID: 15472941 DOI: 10.1002/chem.200400293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The structure and reactivity of gaseous H5P2O8- ions obtained from the chemical ionization (CI) of an H4P2O7/H2O mixture and from electrospray ionization (ESI) of CH3CN/H2O/H4P2O7 solutions were investigated by Fourier transform ion cyclotron (FTICR) and triple quadrupole mass spectrometry. Theoretical calculations performed at the B3LYP/6-31+G* level of theory and collisionally activated dissociation (CAD) mass spectrometric results allowed the ionic population obtained in the CI conditions to be structurally characterized as a mixture of gaseous [H3P2O7...H2O]-, [H3PO4...H2PO4]-, and [PO3...H3PO4...H2O]- clusters. The energy profile emerging from theoretical calculations affords insight into the mechanism of diphosphate ion hydrolysis and synthesis.
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Affiliation(s)
- Federico Pepi
- Dip.to di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università di Roma La Sapienza, P.le A. Moro, 5 00185 Rome, Italy
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Petzold CJ, Leavell MD, Leary JA. Screening and identification of acidic carbohydrates in bovine colostrum by using ion/molecule reactions and Fourier transform ion cyclotron resonance mass spectrometry: specificity toward phosphorylated complexes. Anal Chem 2004; 76:203-10. [PMID: 14697052 DOI: 10.1021/ac034682v] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A screening method was developed for the identification of acidic saccharides from biological mixtures utilizing gas-phase derivatization and mass spectrometry. Phosphorylated compounds were differentiated from other acidic species by exploiting the selective reactivity of chlorotrimethylsilane with the phosphate ions (phosphorylated compounds shift by 72 Da, allowing rapid compound detection). A 13-component mock mixture was used to demonstrate the viability of the method, and a detection limit of 600 nM (30 fmol) was determined. This method was applied to the identification of acidic compounds from bovine colostrum. To further verify the selectivity of the ion/molecule reaction, exact mass measurements were used to determine the elemental composition of 14 compounds. Eight novel acidic carbohydrate species were observed in bovine colostrum, six of which have never been reported previously in milks. Tandem mass spectrometric experiments allowed compound characterization for two of these components.
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Gao H, Petzold CJ, Leavell MD, Leary JA. Investigation of ion/molecule reactions as a quantification method for phosphorylated positional isomers. an FT-ICR approach. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2003; 14:916-924. [PMID: 12892915 DOI: 10.1016/s1044-0305(03)00401-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A rapid and accurate method of quantifying positional isomeric mixtures of phosphorylated hexose and N-acetylhexosamine monosacchrides by using gas-phase ion/molecule reactions coupled with FT-ICR mass spectrometry is described. Trimethyl borate, the reagent gas, reacts readily with the singly charged negative ions of phosphorylated monosaccharides to form two stable product ions corresponding to the loss of one or two neutral molecules of methanol from the original adduct. Product distribution in the ion/molecule reaction spectra differs significantly for isomers phosphorylated in either the 1- or the 6-position. As a result, the percents of total ion current of these product ions for a mixture of the two isomers vary with its composition. In order to determine the percentage of each isomer in an unknown mixture, a multicomponent quantification method is utilized in which the percents of total ion current of the two product ions for each pure monosaccharide phosphate and the mixture are used in a two-equation, two-unknown system. The applicability of this method is demonstrated by successfully quantifying mock mixtures of four different isomeric pairs: Glucose-1-phosphate and glucose-6-phosphate; mannose-1-phosphate and mannose-6-phosphate; galactose-1-phosphate and galactose-6-phosphate; N-acetylglucosamine-1-phosphate and N-acetylglucosamine-6-phosphate. The effects of mixture concentrations and ion/molecule reaction conditions on the quantification are also discussed. Our results demonstrate that this assay is a fast, sensitive, and robust method to quantify isomeric mixtures of phosphorylated monosaccharides.
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Affiliation(s)
- Hong Gao
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA
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Leavell MD, Leary JA. Probing isomeric differences of phosphorylated carbohydrates through the use of ion/molecule reactions and FT-ICR MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2003; 14:323-331. [PMID: 12686479 DOI: 10.1016/s1044-0305(03)00067-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Through the use of ion/molecule reactions and tandem mass spectrometry, phosphate position is assigned in both phosphorylated monosaccharides and oligosaccharides. In previous work phosphate moieties of monosaccharides were stabilized under collisional activation, by first derivatizing the deprotonated monosaccharide with trimethyl borate through an ion/molecule reaction, and the phosphate position determined through marker ions generated in tandem mass spectra. In this work, the methodology is extended to larger phosphorylated oligomers employing chlorotrimethylsilane (TMSCl) as the ion/molecule reagent. Phosphorylated monosaccharides were first investigated to determine diagnostic ions for phosphate linkage in monomeric standards. It was observed that the diagnostic ions showed both linkage and some monosaccharide stereochemical information. Furthermore, it was observed that TMS addition stabilized the phosphate moiety under collisionally activated conditions. Upon identification of the diagnostic ions, the methodology was applied to lactose-1-phosphate. It was found that TMSCl, stabilized the phosphate moiety upon collisional activation, and furthermore, the phosphate linkage could be determined through tandem mass spectrometric analysis. As a further extrapolation to biologically relevant problems, the methodology was applied to a lipophosphoglycan analog from the protozoan parasite Leishmania. This sample contains bridging phosphates which were converted to terminal phosphates through collision induced dissociation. The sample was then analyzed in the same manner as lactose-1-phosphate, yielding phosphate linkage information and stereochemical information. This study showed that, using the developed methodology, phosphate linkage can be determined from both monosaccharides and larger oligosaccharides; furthermore it is applicable to samples in which the phosphates are either terminating or bridging.
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Affiliation(s)
- M D Leavell
- Department of Chemistry, University of California at Berkeley, 94720, USA
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