1
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Williamson DL, Windsor HM, Nagy G. Isolating the Contributions from Moments of Inertia in Isotopic Shifts Measured by High-Resolution Cyclic Ion Mobility Separations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024. [PMID: 38654703 DOI: 10.1021/jasms.4c00082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The unexpected finding that isotopomers (i.e., isotopic isomers) can be separated with high-resolution ion mobility spectrometry-mass spectrometry (IMS-MS) has raised new structural considerations affecting an ion's mobility, namely its center of mass (CoM) and moments of inertia (MoI). Unfortunately, thus far, no studies have attempted to experimentally isolate either CoM or MoI, as they are intrinsically linked by their definitions, where MoI is calculated in relation to CoM. In this study, we designed and synthesized four isotopically labeled tetrapropylammonium (TAA3) ions, each with a unique mass distribution. Three of the synthesized TAA3 ions were labeled symmetrically, thus having identical CoM but differing MoI, which we verified using density functional theory (DFT) calculations. Consequently, we were able to isolate the effect of MoI changes in high-resolution IMS-MS separations. Cyclic ion mobility spectrometry-mass spectrometry (cIMS-MS) separations of the isotopically labeled TAA3 variants revealed isotopic mobility shifts attributable solely to changes in MoI. A 60-m cIMS-MS separation demonstrated that two nominally isobaric TAA3 pseudoisotopomers could be partially resolved, showcasing potential feasibility for isotopomer separations on commercially available IMS-MS platforms. With our previously established collision cross section (CCS) calibration protocol, we also quantified the relationship between MoI and CCS. Our results represent the first demonstration of IMS-MS separations based solely on MoI differences. We believe these findings will contribute important evidence to the growing body of literature on the physical nature of isotopic shifts in IMS-MS separations and work toward more accurate CCS predictions.
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Affiliation(s)
- David L Williamson
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Haisley M Windsor
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Gabe Nagy
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
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2
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Williamson DL, Nagy G. Coupling Isotopic Shifts with Collision Cross-Section Measurements for Carbohydrate Characterization in High-Resolution Ion Mobility Separations. Anal Chem 2023; 95:13992-14000. [PMID: 37683280 PMCID: PMC10538943 DOI: 10.1021/acs.analchem.3c02619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Herein, we introduce a two-dimensional strategy to better characterize carbohydrate isomers. In a single experiment, we can derive cyclic ion mobility-mass spectrometry (cIMS-MS)-based collision cross-section (CCS) values in conjunction with measuring isotopic shifts through the relative arrival times of light and heavy isotopologues. These isotopic shifts were introduced by permethylating carbohydrates with either light, CH3, or heavy, CD3, labels at every available hydroxyl group to generate a light/heavy pair of isotopologues for every individual species analyzed. We observed that our calculated CCS values, which were exclusively measured for the light isotopologues, were orthogonal to our measured isotopic shifts (i.e., relative arrival time values between heavy and light permethylated isotopologues). Our permethylation-induced isotopic shifts scaled well with increasing molecular weight, up to ∼m/z 1300, expanding the analysis of isotopic shifts to molecules 3-4 times as large as those previously studied. Our presented use of coupling CCS values with the measurement of isotopic shifts in a single cIMS-MS experiment is a proof-of-concept demonstration that our two-dimensional approach can improve the characterization of challenging isomeric carbohydrates. We envision that our presented 2D approach will have broad utility for varying molecular classes as well as being amenable to many forms of derivatization.
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Affiliation(s)
- David L Williamson
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Gabe Nagy
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
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3
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Pathak P, Shvartsburg AA. High-Definition Differential Ion Mobility Spectrometry with Structural Isotopic Shifts for Anionic Compounds. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023. [PMID: 37319378 DOI: 10.1021/jasms.3c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Differential ion mobility spectrometry (FAIMS) had emerged in the 2000s as a novel tool for postionization separations in conjunction with mass spectrometry (MS). High-definition FAIMS introduced a decade ago has enabled resolution of peptide, lipid, and other molecular isomers with minute structural variations and recently the isotopic shift analyses where the spectral pattern for stable isotopes fingerprints the ion geometry. Those studies, including all isotopic shift analyses, were in the positive mode. Here, we achieve the same high resolution for anions exemplified by phthalic acid isomers. The resolving power and magnitude of isotopic shifts are in line with the metrics for analogous haloaniline cations, establishing high-definition negative-mode FAIMS with structurally specific isotopic shifts. Different shifts (including the new 18O) remain additive and mutually orthogonal, demonstrating the generality of those properties across the elements and charge states. Expanding to common (not halogenated) organic compounds is a key step toward the broad use of FAIMS isotopic shift methodology.
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Affiliation(s)
- Pratima Pathak
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A Shvartsburg
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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4
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Williamson DL, Trimble TK, Nagy G. Hydrogen-Deuterium-Exchange-Based Mass Distribution Shifts in High-Resolution Cyclic Ion Mobility Separations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023. [PMID: 37098274 DOI: 10.1021/jasms.3c00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The mass distribution of ions influences separations in ion mobility spectrometry-mass spectrometry (IMS-MS). Herein, we introduce a method to induce mass distribution shifts for various analytes using hydrogen-deuterium exchange (HDX) immediately prior to ionization using a dual syringe approach. By replacing labile hydrogens on analytes with deuteriums, we were able to differentiate isomers using separations of isotopologues. For each analyte studied, every possible level of deuteration (from undeuterated to fully deuterated) was generated and then separated using cyclic ion mobility spectrometry-mass spectrometry (cIMS-MS). The information gained from such separations (relative arrival times; tRel. values) was found to be orthogonal to conventional IMS-MS separations. Additionally, the observed shifts were linearly additive with increasing deuteration, suggesting that this methodology could be extended to analytes with a larger number of labile hydrogens. For one isomer pair, as few as two deuteriums were able to produce a large enough mass distribution shift to differentiate isomers. In another experiment, we found that the mass distribution shift was large enough to overcome the reduced mass contribution, resulting in a "flipped" arrival time where the heavier deuterated isotopologue arrived before the lighter one. In this work, we present a proof-of-concept demonstration that mass-distribution-based shifts, tRel. values, could potentially act as an added dimension to characterize molecules in IMS-MS. We anticipate, along with future work in this area, that mass-distribution-based shifts could enable the identification of unknown molecules through a database-driven approach in an analogous fashion to collision cross section (CCS) measurements.
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Affiliation(s)
- David L Williamson
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Tyson K Trimble
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Gabe Nagy
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
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5
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Pathak P, Shvartsburg AA. High-Definition Ion Mobility/Mass Spectrometry with Structural Isotopic Shifts for Nominally Isobaric Isotopologues. J Phys Chem A 2023; 127:3914-3923. [PMID: 37083428 DOI: 10.1021/acs.jpca.3c01792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
We had reported the isotopic envelopes in differential IMS (FAIMS) separations depending on the ion structure. However, this new approach to distinguish isomers was constrained by the unit-mass resolution commingling all nominally isobaric isotopologues. Here, we directly couple high-definition FAIMS to ultrahigh-resolution (Orbitrap) MS and employ the resulting platform to explore the FAIMS spectra for isotopic fine structure. The peak shifts therein for isotopologues of halogenated anilines with 15N and 13C (split by 6 mDa) in N2/CO2 buffers dramatically differ, more than for the 13C, 37Cl, or 81Br species apart by 1 or 2 Da. The shifts in FAIMS space upon different elemental isotopic substitutions are orthogonal mutually and to the underlying separations, forming fingerprint multidimensional matrices and 3-D trajectories across gas compositions that redundantly delineate all isomers considered. The interlocking instrumental and methodological upgrades in this work take the structural isotopic shift approach to the next level.
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Affiliation(s)
- Pratima Pathak
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A Shvartsburg
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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Williamson DL, Nagy G. Isomer and Conformer-Specific Mass Distribution-Based Isotopic Shifts in High-Resolution Cyclic Ion Mobility Separations. Anal Chem 2022; 94:12890-12898. [PMID: 36067027 DOI: 10.1021/acs.analchem.2c02991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we present the use of mass distribution-based isotopic shifts in high-resolution cyclic ion mobility spectrometry-mass spectrometry (cIMS-MS)-based separations to characterize various isomeric species as well as conformers. Specifically, by using the observed relative arrival time values for the isotopologues found in the isotopic envelope after long pathlength cIMS-MS separations, we were able to distinguish dibromoaniline, dichloroaniline, and quaternary ammonium salt isomers, as well as a pair of 25-hydroxyvitamin D3 conformers based on their respective mass distribution-based shifts. Our observed shifts were highly reproducible and broadly applied to the isotopologues of various atoms (i.e., Cl, Br, and C). Additionally, through a control experiment, we determined that such shifts are indeed pathlength-independent, thus demonstrating that our presented methodology could be readily extended to other high-resolution IMS-MS platforms. These results are the first characterization of conformers using mass distribution-based IMS-MS shifts, as well as the first use of a commercial cIMS-MS platform to characterize isomers via their mass distribution-based shifts. We anticipate that our methodology will have broad applicability for biological analytes and that mass distribution-based shifts could potentially act as an added dimension of analysis in existing IMS-MS workflows in omics-based research. Specifically, we envision that the development of a database of these mass distribution-based shifts could, for example, enable the identification of unknown metabolites in complex matrices.
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Affiliation(s)
- David L Williamson
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Gabe Nagy
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
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Pathak P, Shvartsburg AA. Assessing the Dipole Moments and Directional Cross Sections of Proteins and Complexes by Differential Ion Mobility Spectrometry. Anal Chem 2022; 94:7041-7049. [PMID: 35500292 DOI: 10.1021/acs.analchem.2c00343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ion mobility spectrometry (IMS) has become a mainstream approach to fractionate complex mixtures, separate isomers, and assign the molecular geometries. All modalities were grouped into linear IMS (based on the absolute ion mobility, K) and field asymmetric waveform IMS (FAIMS) relying on the evolution of K at a high normalized electric field (E/N) that induces strong ion heating. In the recently demonstrated low-field differential (LOD) IMS, the field is too weak for significant heating but locks the macromolecular dipoles to produce novel separations controlled by the relevant directional collision cross sections (CCSs). Here, we show LODIMS for mass-selected species, exploring the dipole alignment across charge states for the monomers and dimers of an exemplary protein, the alcohol dehydrogenase. Distinct conformational families for aligned species are revealed with directional CCS estimated from the field-dependent trend lines. We set up a model to extract the fractions of pendular conformers as a function of field intensity and translate them into dipole moment distributions. These developments make a critical step toward establishing LODIMS as a new tool for top-down proteomics and integrative structural biology.
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Affiliation(s)
- Pratima Pathak
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A Shvartsburg
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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8
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Pathak P, Sarycheva A, Baird MA, Shvartsburg AA. Delineation of Isomers by the 13C Shifts in Ion Mobility Spectra. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:340-345. [PMID: 33201698 DOI: 10.1021/jasms.0c00350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Mass spectrometry (MS) and isotopes were intertwined for a century, with stable isotopes central to many MS identification and quantification protocols. In contrast, the analytical separations including ion mobility spectrometry (IMS) largely ignored isotopes, partly because of insufficient resolution. We recently delineated various halogenated aniline isomers by structurally specific splitting in FAIMS spectra. While this capability hinges on the 13C shifts, all preceding studies leveraged 37Cl or 81Br to enhance the differentiation. However, such abundant heavy isotopes are absent from typical organic compounds. With single I isotope, iodinated organics generate similar isotopic envelopes dominated by the 13C atoms. Here, we distinguish the three monoiodoaniline isomers based on the shifts solely for one or two 13C atoms. The differentiation may be somewhat improved using multipoint peak position descriptions for more reproducible shifts. The interisomer order of shifts differs from those for chlorinated or brominated analogues, showcasing the specificity of approach. We also investigated the mass scaling of isotopic shifts, encountering divergent trends for different structural families.
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Affiliation(s)
- Pratima Pathak
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Anastasia Sarycheva
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Matthew A Baird
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A Shvartsburg
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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Schaefer C, Kirk AT, Allers M, Zimmermann S. Ion Mobility Shift of Isotopologues in a High Kinetic Energy Ion Mobility Spectrometer (HiKE-IMS) at Elevated Effective Temperatures. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:2093-2101. [PMID: 32875796 DOI: 10.1021/jasms.0c00220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ion mobility spectrometers (IMS) separate ions mainly by ion-neutral collision cross section and to a lesser extent by ion mass and effective temperature. When investigating isotopologues, the difference in collision cross section can be assumed negligible. Since the mobility shift of isotopologues is thus mainly caused by their difference in mass and effective temperature, the investigation of isotopologues can provide important insights into the theory of ion mobility. However, in classical IMS operated at ambient pressure, cluster formation with neutral molecules occurs, which significantly influences the mobility shift of isotopologues and thus makes a sound investigation of the effect of ion mass and effective temperature on the ion mobility difficult. In this work, the relative ion mobility of several organic compounds and their 13C-labeled isotopologues is studied in a High Kinetic Energy Ion Mobility Spectrometer (HiKE-IMS) at high reduced electric fields up to 120 Td, which allows the investigation of nonclustered ion species and thus enables a sound investigation of the mobility shift of isotopologues. The results show that the measured relative ion mobilities of isotopologues having the same effective temperature and, thus, their ion mass dominating the relative ion mobility agree well with theoretical relative ion mobilities predicted by the theory of ion mobility.
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Affiliation(s)
- Christoph Schaefer
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstr. 9A, 30167 Hannover, Germany
| | - Ansgar T Kirk
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstr. 9A, 30167 Hannover, Germany
| | - Maria Allers
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstr. 9A, 30167 Hannover, Germany
| | - Stefan Zimmermann
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstr. 9A, 30167 Hannover, Germany
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10
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Grimes N, Vuppala S, Ayodeji I, Donovan J, Evans-Nguyen T. Enabling Field Asymmetric Ion Mobility Spectrometry Separation of Fentanyl-Related Compounds Using Controlled Humidity. Anal Chem 2020; 92:2917-2921. [PMID: 31976655 DOI: 10.1021/acs.analchem.9b02997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Due to the widespread abuse of opioids in recent years, the development of quick and reliable methods for analyzing compounds such as fentanyl and its derivatives is increasingly important. Ahead of online mass spectrometric analysis, field asymmetric ion mobility spectrometry (FAIMS) has previously been used for rapid ion prefiltering and demonstrated significantly improved peak capacity with the addition of vapor modifiers to the carrier gas. The application of FAIMS-mass spectrometry (MS) in the analysis of fentanyl and related compounds is presented herein with the use of a water vapor modifier. The inclusion of the water vapor modifier to the FAIMS methodology is made more robust with the incorporation of a humidity sensor. A dramatic improvement in the separation of fentanyl, alfentanil, 4-aminophenyl-1-phenethylpiperidine (4-ANPP), norfentanyl, and heroin has been achieved, and the ability to distinguish the isobars in a mixture, alfentanil and ortho-isopropyl furanyl fentanyl, is demonstrated without lengthy chromatography.
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Affiliation(s)
- Nathan Grimes
- University of South Florida , Tampa , Florida 33620 , United States
| | - Sinduri Vuppala
- University of South Florida , Tampa , Florida 33620 , United States
| | - Ifeoluwa Ayodeji
- University of South Florida , Tampa , Florida 33620 , United States
| | - Joanne Donovan
- University of South Florida , Tampa , Florida 33620 , United States
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11
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Pathak P, Baird MA, Shvartsburg AA. Structurally Informative Isotopic Shifts in Ion Mobility Spectra for Heavier Species. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:137-145. [PMID: 32881519 DOI: 10.1021/jasms.9b00018] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The isotopic molecular envelopes due to stable isotopes for most elements were a staple of mass spectrometry since its origins, often leveraged to identify and quantify compounds. However, all isomers share one MS envelope. As the molecular motion in media also depends on the isotopic composition, separations such as liquid chromatography (LC) and ion mobility spectrometry (IMS) must also feature isotopic envelopes. These were largely not observed because of limited resolution, except for the (structurally uninformative) shifts in LC upon H/D exchange. We recently found the isotopic shifts in FAIMS for small haloanilines (∼130-170 Da) to hinge on the halogen position, opening a novel route to isomer characterization. Here, we extend the capability to heavier species: dibromoanilines (DBAs, ∼250 Da) and tribromoanilines (TBAs, ∼330 Da). The 13C shifts for DBAs and TBAs vary across isomers, some changing sign. While 81Br shifts are less specific, the 2-D 13C/81Br shifts unequivocally differentiate all isomers. The trends for DBAs track those for dichloroanilines, with the 13C shift order preserved for most isomers. The peak broadening due to merged isotopomers is also isomer-specific. The absolute shifts for TBAs are smaller than those for lighter haloanilines, but differentiate isomers as well because of compressed uncertainties. These results showcase the feasibility of broadly distinguishing isomers in the more topical ∼200-300 Da range using the isotopic shifts in IMS spectra.
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Affiliation(s)
- Pratima Pathak
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Matthew A Baird
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A Shvartsburg
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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12
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Wojcik R, Nagy G, Attah IK, Webb IK, Garimella SVB, Weitz KK, Hollerbach A, Monroe ME, Ligare MR, Nielson FF, Norheim RV, Renslow RS, Metz TO, Ibrahim YM, Smith RD. SLIM Ultrahigh Resolution Ion Mobility Spectrometry Separations of Isotopologues and Isotopomers Reveal Mobility Shifts due to Mass Distribution Changes. Anal Chem 2019; 91:11952-11962. [PMID: 31450886 PMCID: PMC7188075 DOI: 10.1021/acs.analchem.9b02808] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report on separations of ion isotopologues and isotopomers using ultrahigh-resolution traveling wave-based Structures for Lossless Ion Manipulations with serpentine ultralong path and extended routing ion mobility spectrometry coupled to mass spectrometry (SLIM SUPER IMS-MS). Mobility separations of ions from the naturally occurring ion isotopic envelopes (e.g., [M], [M+1], [M+2], ... ions) showed the first and second isotopic peaks (i.e., [M+1] and [M+2]) for various tetraalkylammonium ions could be resolved from their respective monoisotopic ion peak ([M]) after SLIM SUPER IMS with resolving powers of ∼400-600. Similar separations were obtained for other compounds (e.g., tetrapeptide ions). Greater separation was obtained using argon versus helium drift gas, as expected from the greater reduced mass contribution to ion mobility described by the Mason-Schamp relationship. To more directly explore the role of isotopic substitutions, we studied a mixture of specific isotopically substituted (15N, 13C, and 2H) protonated arginine isotopologues. While the separations in nitrogen were primarily due to their reduced mass differences, similar to the naturally occurring isotopologues, their separations in helium, where higher resolving powers could also be achieved, revealed distinct additional relative mobility shifts. These shifts appeared correlated, after correction for the reduced mass contribution, with changes in the ion center of mass due to the different locations of heavy atom substitutions. The origin of these apparent mass distribution-induced mobility shifts was then further explored using a mixture of Iodoacetyl Tandem Mass Tag (iodoTMT) isotopomers (i.e., each having the same exact mass, but with different isotopic substitution sites). Again, the observed mobility shifts appeared correlated with changes in the ion center of mass leading to multiple monoisotopic mobilities being observed for some isotopomers (up to a ∼0.04% difference in mobility). These mobility shifts thus appear to reflect details of the ion structure, derived from the changes due to ion rotation impacting collision frequency or momentum transfer, and highlight the potential for new approaches for ion structural characterization.
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Affiliation(s)
- Roza Wojcik
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Gabe Nagy
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Isaac. K. Attah
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Ian K. Webb
- Department of Chemistry, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
| | - Sandilya V. B. Garimella
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Karl K. Weitz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Adam Hollerbach
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Matthew E. Monroe
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Marshall R. Ligare
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Felicity F. Nielson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Randolph V. Norheim
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Ryan S. Renslow
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Thomas O. Metz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Yehia M. Ibrahim
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Richard D. Smith
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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13
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Gabelica V, Shvartsburg AA, Afonso C, Barran P, Benesch JL, Bleiholder C, Bowers MT, Bilbao A, Bush MF, Campbell JL, Campuzano ID, Causon T, Clowers BH, Creaser CS, De Pauw E, Far J, Fernandez‐Lima F, Fjeldsted JC, Giles K, Groessl M, Hogan CJ, Hann S, Kim HI, Kurulugama RT, May JC, McLean JA, Pagel K, Richardson K, Ridgeway ME, Rosu F, Sobott F, Thalassinos K, Valentine SJ, Wyttenbach T. Recommendations for reporting ion mobility Mass Spectrometry measurements. MASS SPECTROMETRY REVIEWS 2019; 38:291-320. [PMID: 30707468 PMCID: PMC6618043 DOI: 10.1002/mas.21585] [Citation(s) in RCA: 288] [Impact Index Per Article: 57.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/01/2018] [Accepted: 11/02/2018] [Indexed: 05/02/2023]
Abstract
Here we present a guide to ion mobility mass spectrometry experiments, which covers both linear and nonlinear methods: what is measured, how the measurements are done, and how to report the results, including the uncertainties of mobility and collision cross section values. The guide aims to clarify some possibly confusing concepts, and the reporting recommendations should help researchers, authors and reviewers to contribute comprehensive reports, so that the ion mobility data can be reused more confidently. Starting from the concept of the definition of the measurand, we emphasize that (i) mobility values (K0 ) depend intrinsically on ion structure, the nature of the bath gas, temperature, and E/N; (ii) ion mobility does not measure molecular surfaces directly, but collision cross section (CCS) values are derived from mobility values using a physical model; (iii) methods relying on calibration are empirical (and thus may provide method-dependent results) only if the gas nature, temperature or E/N cannot match those of the primary method. Our analysis highlights the urgency of a community effort toward establishing primary standards and reference materials for ion mobility, and provides recommendations to do so. © 2019 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Valérie Gabelica
- University of Bordeaux, INSERM and CNRS, ARNA Laboratory, IECB site2 rue Robert Escarpit, 33600PessacFrance
| | | | | | - Perdita Barran
- Michael Barber Centre for Collaborative Mass SpectrometryManchester Institute for Biotechnology, University of ManchesterManchesterUK
| | - Justin L.P. Benesch
- Department of Chemistry, Chemistry Research LaboratoryUniversity of Oxford, Mansfield Road, OX1 3TAOxfordUK
| | - Christian Bleiholder
- Department of Chemistry and BiochemistryFlorida State UniversityTallahasseeFlorida32311
| | | | - Aivett Bilbao
- Biological Sciences DivisionPacific Northwest National LaboratoryRichlandWashington
| | - Matthew F. Bush
- Department of ChemistryUniversity of WashingtonSeattleWashington
| | | | | | - Tim Causon
- University of Natural Resources and Life Sciences (BOKU)Department of Chemistry, Division of Analytical ChemistryViennaAustria
| | - Brian H. Clowers
- Department of ChemistryWashington State UniversityPullmanWashington
| | - Colin S. Creaser
- Centre for Analytical ScienceDepartment of Chemistry, Loughborough UniversityLoughboroughUK
| | - Edwin De Pauw
- Laboratoire de spectrométrie de masse (L.S.M.) − Molecular SystemsUniversité de LiègeLiègeBelgium
| | - Johann Far
- Laboratoire de spectrométrie de masse (L.S.M.) − Molecular SystemsUniversité de LiègeLiègeBelgium
| | | | | | | | - Michael Groessl
- Department of Nephrology and Hypertension and Department of BioMedical ResearchInselspital, Bern University Hospital, University of Bern, Switzerland and TofwerkThunSwitzerland
| | | | - Stephan Hann
- University of Natural Resources and Life Sciences (BOKU)Department of Chemistry, Division of Analytical ChemistryViennaAustria
| | - Hugh I. Kim
- Department of ChemistryKorea UniversitySeoulKorea
| | | | - Jody C. May
- Department of ChemistryCenter for Innovative Technology, Vanderbilt UniversityNashvilleTennessee
| | - John A. McLean
- Department of ChemistryCenter for Innovative Technology, Vanderbilt UniversityNashvilleTennessee
| | - Kevin Pagel
- Freie Universitaet BerlinInstitute for Chemistry and BiochemistryBerlinGermany
| | | | | | - Frédéric Rosu
- CNRS, INSERM and University of BordeauxInstitut Européen de Chimie et BiologiePessacFrance
| | - Frank Sobott
- Antwerp UniversityBiomolecular & Analytical Mass SpectrometryAntwerpBelgium
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
- School of Molecular and Cellular BiologyUniversity of LeedsLeedsUK
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of BiosciencesUniversity College LondonLondonWC1E 6BTUK
- United Kingdom and Institute of Structural and Molecular BiologyDepartment of Biological Sciences, Birkbeck College, University of LondonLondonWC1E 7HXUK
| | - Stephen J. Valentine
- C. Eugene Bennett Department of ChemistryWest Virginia UniversityMorgantownWest Virginia
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14
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Baird MA, Pathak P, Shvartsburg AA. Elemental Dependence of Structurally Specific Isotopic Shifts in High-Field Ion Mobility Spectra. Anal Chem 2019; 91:3687-3693. [DOI: 10.1021/acs.analchem.8b05801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Matthew A. Baird
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Pratima Pathak
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A. Shvartsburg
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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15
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Pathak P, Baird MA, Shvartsburg AA. Identification of Isomers by Multidimensional Isotopic Shifts in High-Field Ion Mobility Spectra. Anal Chem 2018; 90:9410-9417. [DOI: 10.1021/acs.analchem.8b02057] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Pratima Pathak
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Matthew A. Baird
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
| | - Alexandre A. Shvartsburg
- Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260, United States
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