1
|
Bell RJ, Hage DS, Dodds ED. Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry by Matrix-Assisted Laser Desorption Ionization. Anal Chem 2024; 96:6584-6587. [PMID: 38619932 DOI: 10.1021/acs.analchem.3c05601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Two-dimensional Fourier transform ion cyclotron resonance (2D FTICR) mass spectrometry is a developing form of data-independent acquisition that allows for the simultaneous fragmentation and correlation of fragment ions to their precursors across a range of m/z values. The modern usage of 2D FTICR is performed using electrospray ionization (ESI) as the dried droplet preparation for matrix-assisted laser desorption ionization (MALDI) does not produce a consistent packet of ions over a number of scans. This work uses pneumatic spray techniques from mass spectrometry imaging to create a homogeneous surface for use with MALDI as an ionization source for 2D FTICR. A mixture of peptides and matrix was deposited onto a glass slide using an HTX pneumatic sprayer. MALDI was then used to ionize the peptide mixture for use with a standard 2D FTICR pulse sequence. The generated 2D spectrum reveals comparable structural information to spectra collected in a 1D experiment. Artifacts observed in the collected 2D MALDI spectra do not significantly differ from those expected from 2D ESI spectra.
Collapse
Affiliation(s)
- Richard J Bell
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0304, United States
| | - David S Hage
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0304, United States
| | - Eric D Dodds
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0304, United States
| |
Collapse
|
2
|
Saller KM, Pernusch DC, Schwarzinger C. MALINTO: A New MALDI Interpretation Tool for Enhanced Peak Assignment and Semiquantitative Studies of Complex Synthetic Polymers. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:293-303. [PMID: 36599090 PMCID: PMC9896554 DOI: 10.1021/jasms.2c00311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
The newly developed MALDI interpretation tool ("MALINTO") allows for the accelerated characterization of complex synthetic polymers via MALDI mass spectrometry. While existing software provides solutions for simple polymers like poly(ethylene glycol), polystyrene, etc., they are limited in their application on polycondensates synthesized from two different kinds of monomers (e.g., diacid and diol in polyesters). In addition to such A2 + B2 polycondensates, MALINTO covers branched and even multicyclic polymer systems. Since the MALINTO software works based on input data of monomers/repeating units, end groups, and adducts, it can be applied on polymers whose components are previously known or elucidated. Using these input data, a list with theoretically possible polymer compositions and resulting m/z values is calculated, which is further compared to experimental mass spectrometry data. For optional semiquantitative studies, peak areas are allocated according to their assigned polymer composition to evaluate both comonomer and terminating group ratios. Several tools are implemented to avoid mistakes, for example, during peak assignment. In the present publication, the functions of MALINTO are described in detail and its broad applicability on different linear polymers as well as branched and multicyclic polycondensates is demonstrated. Fellow researchers will benefit from the accelerated peak assignment using the freely available MALINTO software and might be encouraged to explore the potential of MALDI mass spectrometry for (semi)quantitative applications.
Collapse
Affiliation(s)
- Klara M. Saller
- Institute
for Chemical Technology of Organic Materials, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040Linz, Austria
| | - Daniel C. Pernusch
- Institute
for Chemical Technology of Organic Materials, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040Linz, Austria
| | - Clemens Schwarzinger
- Institute
for Chemical Technology of Organic Materials, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040Linz, Austria
| |
Collapse
|
3
|
Muyizere T, Mukiza J. Progress on the development of a metal salt-assisted ionization source for the mass spectrometric analysis of polymers. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:2803-2819. [PMID: 35848110 DOI: 10.1039/d2ay00724j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The mass spectrometric analysis of polymers has been addressed as a challenging research topic due to poor ionization and complicated analysis using conventional mass spectrometry. The ionization source has demonstrated a promising future in rapid mass spectrometric analysis. Soft ionization techniques, such as electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) are the most ionization sources appeared to be a powerful tools for polymer characterization when combined with MS. However, they always need metal salts to be introduced during the ionization protocol for polymers due to the crucial role played by their ions (cations and anions). The current review focuses on the progress in the development of metal ion-assisted-ionization sources for the mass spectrometric analysis of polymers. Different ionization systems are comprehensively reviewed. The application of metal ion-assisted ESI, nanoESI, PSI, and MALDI-MS for polymer sample analyses is systematically discussed. The future research trends and challenges in this cutting-edge research field are summarized. It also aims to provide the current state-of-the-art of metal salts as a platform for ionization systems for the mass spectrometric characterization of polymers and offers the current challenges and perspectives on the promising future to improve analytical performance in this field. Finally, this mini-review provides a comprehensive handbook to researchers from different research backgrounds wishing to work in this area.
Collapse
Affiliation(s)
- Theoneste Muyizere
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100039, China
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, No. 11 Beiyitiao, Zhongguancun, 100190 Beijing, China.
| | - Janvier Mukiza
- Rwanda Food and Drugs Authority, Kigali 1948, Rwanda.
- School of Education, College of Education, University of Rwanda, P. O. BOX 55, Rwamagana, Rwanda
| |
Collapse
|
4
|
Blaj DA, Balan-Porcarasu M, Petre BA, Harabagiu V, Peptu C. MALDI mass spectrometry monitoring of cyclodextrin-oligolactide derivatives synthesis. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.124186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
5
|
Nambiar S, Kahn N, Gummer JPA. Matrix-Assisted Laser Desorption Ionization Mass Spectrometry Imaging by Freeze-Spot Deposition of the Matrix. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1829-1836. [PMID: 34047188 DOI: 10.1021/jasms.1c00063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Imaging mass spectrometry has emerged as a powerful metabolite measurement approach to capture the spatial dimension of metabolite distribution in a biological sample. In matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI), deposition of the chemical-matrix onto the sample serves to simultaneously extract biomolecules to the sample surface and concurrently render the sample amenable to MALDI. However, matrix application may mobilize sample metabolites and will dictate the efficiency of matrix crystallization, together limiting the lateral resolution which may be optimally achieved by MSI. Here, we describe a matrix application technique, herein referred to as the "freeze-spot" method, conceived as a low-cost preparative approach requiring minimal amounts of chemical matrix while maintaining the spatial dimension of sample metabolites for MALDI-MSI. Matrix deposition was achieved by pipette spot application of the matrix-solubilized within a solvent solution with a freezing point above that of a chilled sample stage to which the sample section is mounted. The matrix solution freezes on contact with the sample and the solvent is removed by sublimation, leaving a fine crystalline matrix on the sample surface. Freeze-spotting is quick to perform, found particularly useful for MALDI-MSI of small sample sections, and well suited to efficient and cost-effective method development pipelines, while capable of maintaining the lateral resolution required by MSI.
Collapse
Affiliation(s)
- Shabarinath Nambiar
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Nusrat Kahn
- School of Environmental Science, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Joel P A Gummer
- School of Science, Edith Cowan University, Joondalup, Western Australia 6027, Australia
- ChemCentre, Bentley, Western Australia 6102, Australia
| |
Collapse
|
6
|
McCann A, Rappe S, La Rocca R, Tiquet M, Quinton L, Eppe G, Far J, De Pauw E, Kune C. Mass shift in mass spectrometry imaging: comprehensive analysis and practical corrective workflow. Anal Bioanal Chem 2021; 413:2831-2844. [PMID: 33517478 DOI: 10.1007/s00216-021-03174-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/22/2020] [Accepted: 01/13/2021] [Indexed: 12/19/2022]
Abstract
MALDI mass spectrometry imaging (MSI) allows the mapping and the tentative identification of compounds based on their m/z value. In typical MSI, a spectrum is taken at incremental 2D coordinates (pixels) across a sample surface. Single pixel mass spectra show the resolving power of the mass analyzer. Mass shift, i.e., variations of the m/z of the same ion(s), may occur from one pixel to another. The superposition of shifted masses from individual pixels peaks apparently degrades the resolution and the mass accuracy in the average spectrum. This leads to low confidence annotations and biased localization in the image. Besides the intrinsic performances of the analyzer, the sample properties (local composition, thickness, matrix deposition) and the calibration method are sources of mass shift. Here, we report a critical analysis and recommendations to mitigate these sources of mass shift. Mass shift 2D distributions were mapped to illustrate its effect and explore systematically its origin. Adapting the sample preparation, carefully selecting the data acquisition settings, and wisely applying post-processing methods (i.e., m/z realignment or individual m/z recalibration pixel by pixel) are key factors to lower the mass shift and to improve image quality and annotations. A recommended workflow, resulting from a comprehensive analysis, was successfully applied to several complex samples acquired on both MALDI ToF and MALDI FT-ICR instruments.
Collapse
Affiliation(s)
- Andréa McCann
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Sophie Rappe
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Raphaël La Rocca
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Mathieu Tiquet
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Loïc Quinton
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Johann Far
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium
| | - Christopher Kune
- Mass Spectrometry Laboratory, MolSys Research Unit, Department of Chemistry, University of Liège, Allée du Six Août, 11 - Quartier Agora, 4000, Liège, Belgium.
| |
Collapse
|
7
|
Saller KM, Gnatiuk I, Holzinger D, Schwarzinger C. Semiquantitative Approach for Polyester Characterization Using Matrix-Assisted Laser Desorption Ionization/Time-of-Flight Mass Spectrometry Approved by 1H NMR. Anal Chem 2020; 92:15221-15228. [PMID: 33138357 PMCID: PMC7675608 DOI: 10.1021/acs.analchem.0c03844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Matrix-assisted laser desorption ionization/time-of-flight (MALDI/ToF) mass spectrometry and 1H NMR were used for the structural investigation of isophthalic and maleic acid copolyesters with neopentyl glycol. Since both methods provided information on the ratio of incorporated acid components and terminating groups, results were compared and linear correlations (R2 = 0.96-0.98) could be found. This suggests that MALDI/ToF MS is a suitable tool for the semiquantitative characterization of polyester systems. For the isophthalic/maleic acid ratio, MALDI results yielded constantly lower values than 1H NMR, which was attributed to varying ionization efficiencies of homo- and copolyesters. Ratios of carboxylic and hydroxylic terminating groups, which are conventionally still measured by time consuming complex titrations, were measured with MALDI and 1H NMR and were in good agreement. Both methods either excluded or distinguished unreacted monomers in the polyester bulk in contrast to acid-base titrations where those monomers severely distort the results. Additional structural information could be gained including the observation of cyclic structures (MALDI), E/Z isomerism from maleic to fumaric acid, and the statistical distribution of the acid components within the polyester chain (1H NMR). While 1H NMR peak assignments have to be verified by 13C NMR and multidimensional techniques, MALDI/ToF MS provides a straightforward technique that can be applied to other polyester systems without major alterations.
Collapse
Affiliation(s)
- Klara M Saller
- Institute for Chemical Technology of Organic Materials, Johannes Kepler University Linz, Linz 4040, Austria
| | | | | | - Clemens Schwarzinger
- Institute for Chemical Technology of Organic Materials, Johannes Kepler University Linz, Linz 4040, Austria
| |
Collapse
|
8
|
Weidner SM, Kricheldorf HR. Matrix-assisted laser desorption/ionization behavior of neat linear and cyclic poly(L-lactide)s and their blends. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 2:e8673. [PMID: 31760663 DOI: 10.1002/rcm.8673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/08/2019] [Accepted: 11/22/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Steffen M Weidner
- Federal Institute for Materials Research and Testing-BAM, Richard Willstätter Str. 11, D-12489, Berlin, Germany
| | - Hans R Kricheldorf
- Institute of Technical und Macromolecular Chemistry, Bundesstrasse 45, D-20146, Hamburg, Germany
| |
Collapse
|
9
|
Satoh T, Nakamura S, Fouquet T, Sato H, Ueda Y. A mass spectrometry imaging method for visualizing synthetic polymers by using average molecular weight and dispersity as indices. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 2:e8653. [PMID: 31721332 DOI: 10.1002/rcm.8653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/05/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE Matrix-assisted laser desorption/ionization mass spectrometric imaging (MSI) is considered to be a powerful tool for visualizing the spatial distribution of synthetic polymers. However, a conventional method extracting an image of a specific m/z value is not suitable for polymers, which have a mass distribution. It is necessary to develop the visualization method to show the spatial distribution of entire polymer series. METHODS The mass peaks included in polymer series were specified from the average mass spectrum of the entire MSI measurement region by using Kendrick mass defect analysis. The images of those mass peaks were extracted and the number average molecular weight (Mn ), the weight average molecular weight (Mw ) and dispersity (Đ) were calculated for each pixel. Finally, the spatial distribution of the polymer series was summarized to images using Mn , Mw and Đ as indices. RESULTS The effects of the methods were investigated by (i) polymers with different mass distributions and (ii) polymers with different repeat units and end-groups. In both cases, the spatial distribution of specific polymer series including several dozens to hundreds of mass peaks was summarized into three images related to Mn , Mw and Đ, which are familiar indices in polymer analysis. The results are able to provide an overview of the spatial variation of each polymer more intuitively. CONCLUSIONS The visualization of Mn , Mw and Đ will help provide an overview of the spatial distribution of polymer series combined with ion intensity distribution made by conventional methods. It can be also applied to other mass spectrometric imaging methods such as desorption electrospray ionization (DESI) or time-of-flight secondary ion mass spectrometry (TOF-SIMS).
Collapse
Affiliation(s)
| | - Sayaka Nakamura
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8565, Japan
| | - Thierry Fouquet
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8565, Japan
| | - Hiroaki Sato
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8565, Japan
| | | |
Collapse
|
10
|
Papagiannopoulou C, Parchen R, Rubbens P, Waegeman W. Fast Pathogen Identification Using Single-Cell Matrix-Assisted Laser Desorption/Ionization-Aerosol Time-of-Flight Mass Spectrometry Data and Deep Learning Methods. Anal Chem 2020; 92:7523-7531. [PMID: 32330016 DOI: 10.1021/acs.analchem.9b05806] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In diagnostics of infectious diseases, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) can be applied for the identification of pathogenic microorganisms. However, to achieve a trustworthy identification from MALDI-TOF MS data, a significant amount of biomass should be considered. The bacterial load that potentially occurs in a sample is therefore routinely amplified by culturing, which is a time-consuming procedure. In this paper, we show that culturing can be avoided by conducting MALDI-TOF MS on individual bacterial cells. This results in a more rapid identification of species with an acceptable accuracy. We propose a deep learning architecture to analyze the data and compare its performance with traditional supervised machine learning algorithms. We illustrate our workflow on a large data set that contains bacterial species related to urinary tract infections. Overall we obtain accuracies up to 85% in discriminating five different species.
Collapse
Affiliation(s)
| | | | - Peter Rubbens
- Flanders Marine Institute (VLIZ), Ostend 8400, Belgium
| | - Willem Waegeman
- Department of Data Analysis and Mathematical Modelling, Ghent University, Ghent 9000, Belgium
| |
Collapse
|
11
|
Shibamoto K, Furuya D, Fujita T. Ablation controlled laser desorption/ionization mass spectrometry by using improved transmission geometry. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.136892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
12
|
Cai YH, Wang YS. Impact of uneven sample morphology on mass resolving power in linear MALDI-TOF mass spectrometry: A comprehensive theoretical investigation. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:361-368. [PMID: 29388287 DOI: 10.1002/jms.4067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 12/07/2017] [Accepted: 01/19/2018] [Indexed: 06/07/2023]
Abstract
This work discusses the correlation between the mass resolving power of matrix-assisted laser desorption/ionization time-of-flight mass analyzers and extraction condition with an uneven sample morphology. Previous theoretical calculations show that the optimum extraction condition for flat samples involves an ideal ion source design and extraction delay. A general expression of spectral feature takes into account ion initial velocity, and extraction delay is derived in the current study. The new expression extends the comprehensive calculation to uneven sample surfaces and above 90% Maxell-Boltzmann initial velocity distribution of ions to account for imperfect ionization condition. Calculation shows that the impact of uneven sample surface or initial spatial spread of ions is negligible when the extraction delay is away from the ideal value. When the extraction delay approaches the optimum value, the flight-time topology shows a characteristic curve shape, and the time-domain mass spectral feature broadens with an increase in initial spatial spread of ions. For protonated 2,5-dihydroxybenzoic acid, the mass resolving power obtained from a sample of 3-μm surface roughness is approximately 3.3 times lower than that of flat samples. For ions of m/z 3000 coexpanded with 2,5-dihydroxybenzoic acid, the mass resolving power in the 3-μm surface roughness case only reduces roughly 7%. Comprehensive calculations also show that the mass resolving power of lighter ions is more sensitive to the accuracy of the extraction delay than heavier ions.
Collapse
Affiliation(s)
- Yi-Hong Cai
- Genomics Research Center, Academia Sinica, 128, Academia Road, Section 2, Nankang District, Taipei, 115, Taiwan
| | - Yi-Sheng Wang
- Genomics Research Center, Academia Sinica, 128, Academia Road, Section 2, Nankang District, Taipei, 115, Taiwan
| |
Collapse
|
13
|
Lee H, Lai YH, Ou YM, Tsao CW, Jheng YJ, Kuo SY, Chang HT, Wang YS. Enhancing carbohydrate ion yield by controlling crystalline structures in matrix-assisted laser desorption/ionization mass spectrometry. Anal Chim Acta 2017; 994:49-55. [PMID: 29126468 DOI: 10.1016/j.aca.2017.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 10/18/2022]
Abstract
Carbohydrate analysis is challenging due to lack of sensitive detection and efficient separation methods. Although matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is a sensitive tool, the low ionization efficiency of carbohydrates makes mass analyses inefficient. This work systematically examines the correlation between MALDI-MS sensitivity and carbohydrate sample morphology. Depending on the properties of the matrix used, the morphology changes through sample recrystallization after drying or imposition of hydrodynamic flows during droplet drying. Observation shows that amorphous solids and finer crystals offer higher carbohydrate sensitivity and spatial homogeneity than larger crystals. Clear evidences of an inverse correlation between sensitivity and crystal size are obtained when various kinds of carbohydrates are mixed with different matrixes. Similar experiments on proteins and peptides showed a negative or negligible effect. The result serves as a general guideline for improving efficiency in routine carbohydrate analysis.
Collapse
Affiliation(s)
- Hsun Lee
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC
| | - Yin-Hung Lai
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC
| | - Yu-Meng Ou
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC; Chemistry Department, National Taiwan University, Taipei 106, Taiwan, ROC
| | - Chien-Wei Tsao
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC; Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, ROC
| | - Ya-Jin Jheng
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC
| | - Shu-Yun Kuo
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC
| | - Huan-Tsung Chang
- Chemistry Department, National Taiwan University, Taipei 106, Taiwan, ROC
| | - Yi-Sheng Wang
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC.
| |
Collapse
|
14
|
Organic matrices, ionic liquids, and organic matrices@nanoparticles assisted laser desorption/ionization mass spectrometry. Trends Analyt Chem 2017. [DOI: 10.1016/j.trac.2017.01.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
15
|
Wu T, Zhang C, Ren H, Xi Y, Du Y, Peng Y. Solvent effect in polymer analysis by MALDI-TOF mass spectrometry. INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION 2017. [DOI: 10.1080/1023666x.2016.1263913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ting Wu
- School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Chuanjing Zhang
- School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Hongxin Ren
- School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Yidan Xi
- School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Yiping Du
- School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Yaxin Peng
- Department of Mathematics, Shanghai University, Shanghai, China
| |
Collapse
|
16
|
Uliyanchenko E. Applications of Hyphenated Liquid Chromatography Techniques for Polymer Analysis. Chromatographia 2017. [DOI: 10.1007/s10337-016-3193-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
17
|
Wang P, Giese RW. Recommendations for quantitative analysis of small molecules by matrix-assisted laser desorption ionization mass spectrometry. J Chromatogr A 2017; 1486:35-41. [PMID: 28118972 DOI: 10.1016/j.chroma.2017.01.040] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/21/2016] [Accepted: 01/16/2017] [Indexed: 12/15/2022]
Abstract
Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been used for quantitative analysis of small molecules for many years. It is usually preceded by an LC separation step when complex samples are tested. With the development several years ago of "modern MALDI" (automation, high repetition laser, high resolution peaks), the ease of use and performance of MALDI as a quantitative technique greatly increased. This review focuses on practical aspects of modern MALDI for quantitation of small molecules conducted in an ordinary way (no special reagents, devices or techniques for the spotting step of MALDI), and includes our ordinary, preferred methods The review is organized as 18 recommendations with accompanying explanations, criticisms and exceptions.
Collapse
Affiliation(s)
- Poguang Wang
- Department of Pharmaceutical Sciences and Barnett Institute, Bouve College, Northeastern University, Boston, MA 02115, USA
| | - Roger W Giese
- Department of Pharmaceutical Sciences and Barnett Institute, Bouve College, Northeastern University, Boston, MA 02115, USA.
| |
Collapse
|
18
|
Shin D, Kim I, Paek J, Kim J. A Novel “Freeze Vacuum Drying” Crystallization Method Toward Quantitative MALDI-MS. B KOREAN CHEM SOC 2017. [DOI: 10.1002/bkcs.11046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Dongwon Shin
- Department of Chemistry; Chungnam National University; Daejeon 305-764 Republic of Korea
| | - Inyoung Kim
- Department of Chemistry; Chungnam National University; Daejeon 305-764 Republic of Korea
| | - Jihyun Paek
- Department of Chemistry; Chungnam National University; Daejeon 305-764 Republic of Korea
| | - Jeongkwon Kim
- Department of Chemistry; Chungnam National University; Daejeon 305-764 Republic of Korea
| |
Collapse
|
19
|
Ou YM, Tsao CW, Lai YH, Lee H, Chang HT, Wang YS. Preparation of Homogeneous MALDI Samples for Quantitative Applications. J Vis Exp 2016. [PMID: 27842361 DOI: 10.3791/54409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
This protocol demonstrates a simple sample preparation to reduce spatial heterogeneity in ion signals during matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The heterogeneity of ion signals is a severe problem in MALDI, which results in poor data reproducibility and makes MALDI unsuitable for quantitative analysis. By regulating sample plate temperature during sample preparation, thermal-induced hydrodynamic flows inside droplets of sample solution are able to reduce the heterogeneity problem. A room-temperature sample preparation chamber equipped with a temperature-regulated copper base block that holds MALDI sample plates facilitates precise control of the sample drying condition. After drying of sample droplets, the temperature of sample plates is returned to room temperature and removed from the chamber for subsequent mass spectrometric analysis. The areas of samples are examined with MALDI-imaging mass spectrometry to obtain the spatial distribution of all components in the sample. In comparison with the conventional dried-droplet method that prepares samples under ambient conditions without temperature control, the samples prepared with the method demonstrated herein show significantly better spatial distribution and signal intensity. According to observations using carbohydrate and peptide samples, decreasing substrate temperature while maintaining the surroundings at ambient temperature during the drying process can effectively reduce the heterogeneity of ion signals. This method is generally applicable to various combinations of samples and matrices.
Collapse
Affiliation(s)
- Yu-Meng Ou
- Genomic Research Center, Academia Sinica; Department of Chemistry, National Taiwan University
| | - Chien-Wei Tsao
- Genomic Research Center, Academia Sinica; Department of Chemical Engineering and Biotechnology, National Taipei University of Technology
| | | | - Hsun Lee
- Genomic Research Center, Academia Sinica
| | | | | |
Collapse
|
20
|
Lai YH, Cai YH, Lee H, Ou YM, Hsiao CH, Tsao CW, Chang HT, Wang YS. Reducing Spatial Heterogeneity of MALDI Samples with Marangoni Flows During Sample Preparation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1314-21. [PMID: 27126469 DOI: 10.1007/s13361-016-1406-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 04/02/2016] [Accepted: 04/05/2016] [Indexed: 05/20/2023]
Abstract
This work demonstrates a method to prepare homogeneous distributions of analytes to improve data reproducibility in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). Natural-air drying processes normally result in unwanted heterogeneous spatial distributions of analytes in MALDI crystals and make quantitative analysis difficult. This study demonstrates that inducing Marangoni flows within drying droplets can significantly reduce the heterogeneity problem. The Marangoni flows are accelerated by changing substrate temperatures to create temperature gradients across droplets. Such hydrodynamic flows are analyzed semi-empirically. Using imaging mass spectrometry, changes of heterogeneity of molecules with the change of substrate temperature during drying processes are demonstrated. The observed heterogeneities of the biomolecules reduce as predicted Marangoni velocities increase. In comparison to conventional methods, drying droplets on a 5 °C substrate while keeping the surroundings at ambient conditions typically reduces the heterogeneity of biomolecular ions by 65%-80%. The observation suggests that decreasing substrate temperature during droplet drying processes is a simple and effective means to reduce analyte heterogeneity for quantitative applications. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Yin-Hung Lai
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China
| | - Yi-Hong Cai
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China
| | - Hsun Lee
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China
| | - Yu-Meng Ou
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China
- Chemistry Department, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Chih-Hao Hsiao
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China
| | - Chien-Wei Tsao
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 106, Taiwan, Republic of China
| | - Huan-Tsung Chang
- Chemistry Department, National Taiwan University, Taipei, 106, Taiwan, Republic of China
| | - Yi-Sheng Wang
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan, Republic of China.
| |
Collapse
|
21
|
Moskovets E, Misharin A, Laiko V, Doroshenko V. A comparative study on the analytical utility of atmospheric and low-pressure MALDI sources for the mass spectrometric characterization of peptides. Methods 2016; 104:21-32. [DOI: 10.1016/j.ymeth.2016.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/19/2015] [Accepted: 02/16/2016] [Indexed: 11/16/2022] Open
|
22
|
Engler MS, Crotty S, Barthel MJ, Pietsch C, Schubert US, Böcker S. Abundance correction for mass discrimination effects in polymer mass spectra. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1233-1241. [PMID: 28328018 DOI: 10.1002/rcm.7553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/28/2016] [Accepted: 03/04/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is frequently used to analyze homo- and copolymers, i.e. for computing copolymer fingerprints. However, the oligomer abundances are influenced by mass discrimination, i.e. mass- and composition-dependent ionization. We have developed a computational method to correct the abundance bias caused by the mass discrimination. METHODS MALDI-TOFMS in combination with computational methods was used to investigate three random copolymers with different ratios of styrene and isoprene. Furthermore, equimolar high- and low-mass styrene and isoprene homopolymers (2500 and 4200 Da) were mixed and also analyzed by MALDI-TOFMS. The abundances of both copolymers and homopolymers were corrected for mass discrimination effects with our new method. RESULTS The novel computational method was integrated into the existing COCONUT software. The method was demonstrated using the measured styrene and isoprene co- and homopolymers. First, the method was applied to homopolymer spectra. Subsequently, the copolymer fingerprint was computed from the copolymer MALDI mass spectra and the correcting function applied. The changes in the composition are plausible, indicating that correction of copolymer abundances was reasonable. CONCLUSIONS Our computational method may help to avoid erroneous conclusions when analyzing copolymer MS spectra. The software is freely available and represents a step towards comprehensive computational support in polymer science. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Martin S Engler
- Chair of Bioinformatics, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, 07743, Jena, Germany
| | - Sarah Crotty
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
| | - Markus J Barthel
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
| | - Christian Pietsch
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
| | - Sebastian Böcker
- Chair of Bioinformatics, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Humboldstr. 10, 07743, Jena, Germany
| |
Collapse
|
23
|
|
24
|
Limbeck A, Galler P, Bonta M, Bauer G, Nischkauer W, Vanhaecke F. Recent advances in quantitative LA-ICP-MS analysis: challenges and solutions in the life sciences and environmental chemistry. Anal Bioanal Chem 2015; 407:6593-617. [PMID: 26168964 PMCID: PMC4545187 DOI: 10.1007/s00216-015-8858-0] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 06/09/2015] [Accepted: 06/15/2015] [Indexed: 01/29/2023]
Abstract
Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) is a widely accepted method for direct sampling of solid materials for trace elemental analysis. The number of reported applications is high and the application range is broad; besides geochemistry, LA-ICP-MS is mostly used in environmental chemistry and the life sciences. This review focuses on the application of LA-ICP-MS for quantification of trace elements in environmental, biological, and medical samples. The fundamental problems of LA-ICP-MS, such as sample-dependent ablation behavior and elemental fractionation, can be even more pronounced in environmental and life science applications as a result of the large variety of sample types and conditions. Besides variations in composition, the range of available sample states is highly diverse, including powders (e.g., soil samples, fly ash), hard tissues (e.g., bones, teeth), soft tissues (e.g., plants, tissue thin-cuts), or liquid samples (e.g., whole blood). Within this article, quantification approaches that have been proposed in the past are critically discussed and compared regarding the results obtained in the applications described. Although a large variety of sample types is discussed within this article, the quantification approaches used are similar for many analytical questions and have only been adapted to the specific questions. Nevertheless, none of them has proven to be a universally applicable method.
Collapse
Affiliation(s)
- Andreas Limbeck
- Institute of Chemical Technologies and Analytics, Division of Instrumental Analytical Chemistry, TU Wien, Getreidemarkt 9/164, 1060, Vienna, Austria,
| | | | | | | | | | | |
Collapse
|
25
|
Gabriel SJ, Steinhoff RF, Pabst M, Schwarzinger C, Zenobi R, Panne U, Weidner SM. Improved analysis of ultra-high molecular mass polystyrenes in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using DCTB matrix and caesium salts. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1039-1046. [PMID: 26044271 DOI: 10.1002/rcm.7197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
RATIONALE The ionization of polystyrenes in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is typically achieved by the use of silver salts. Since silver salts can cause severe problems, such as cluster formation, fragmentation of polymer chains and end group cleavage, their substitution by alkali salts is highly desirable. METHODS The influence of various cations (Ag(+), Cs(+) and Rb(+)) on the MALDI process of polystyrene (PS) mixtures and high mass polystyrenes was examined. The sample preparation was kept as straightforward as possible. Consequently, no recrystallization or other cleaning procedures were applied. RESULTS The investigation of a polystyrene mixture showed that higher molecular polystyrenes could be more easily ionized using caesium, rather than rubidium or silver salts. In combination with the use of DCTB as matrix a high-mass polymer analysis could be achieved, which was demonstrated by the detection of a 1.1 MDa PS. CONCLUSIONS A fast, simple and robust MALDI sample preparation method for the analysis of ultra-high molecular weight polystyrenes based on the use of DCTB and caesium salts has been presented. The suitability of the presented method has been validated by using different mass spectrometers and detectors.
Collapse
Affiliation(s)
- S J Gabriel
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489, Berlin, Germany
| | - R F Steinhoff
- Eidgenössisch Technische Hochschule Zürich, Department of Chemistry and Applied Biosciences, Vladimir Prelog Weg 3, 8093, Zürich, Switzerland
| | - M Pabst
- Eidgenössisch Technische Hochschule Zürich, Department of Chemistry and Applied Biosciences, Vladimir Prelog Weg 3, 8093, Zürich, Switzerland
| | - C Schwarzinger
- Johannes Kepler Universität Linz, Altenbergerstrasse 69, 4040, Linz, Austria
| | - R Zenobi
- Eidgenössisch Technische Hochschule Zürich, Department of Chemistry and Applied Biosciences, Vladimir Prelog Weg 3, 8093, Zürich, Switzerland
| | - U Panne
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489, Berlin, Germany
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - S M Weidner
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Strasse 11, 12489, Berlin, Germany
| |
Collapse
|
26
|
Rawlins CM, Salisbury JP, Feldman DR, Isim S, Agar NYR, Luther E, Agar JN. Imaging and Mapping of Tissue Constituents at the Single-Cell Level Using MALDI MSI and Quantitative Laser Scanning Cytometry. Methods Mol Biol 2015; 1346:133-49. [PMID: 26542720 DOI: 10.1007/978-1-4939-2987-0_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
For nearly a century, histopathology involved the laborious morphological analyses of tissues stained with broad-spectrum dyes (i.e., eosin to label proteins). With the advent of antibody-labeling, immunostaining (fluorescein and rhodamine for fluorescent labeling) and immunohistochemistry (DAB and hematoxylin), it became possible to identify specific immunological targets in cells and tissue preparations. Technical advances, including the development of monoclonal antibody technology, led to an ever-increasing palate of dyes, both fluorescent and chromatic. This provides an incredibly rich menu of molecular entities that can be visualized and quantified in cells-giving rise to the new discipline of Molecular Pathology. We describe the evolution of two analytical techniques, cytometry and mass spectrometry, which complement histopathological visual analysis by providing automated, cellular-resolution constituent maps. For the first time, laser scanning cytometry (LSC) and matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) are combined for the analysis of tissue sections. The utility of the marriage of these techniques is demonstrated by analyzing mouse brains with neuron-specific, genetically encoded, fluorescent proteins. We present a workflow that: (1) can be used with or without expensive matrix deposition methods, (2) uses LSC images to reveal the diverse landscape of neural tissue as well as the matrix, and (3) uses a tissue fixation method compatible with a DNA stain. The proposed workflow can be adapted for a variety of sample preparation and matrix deposition methods.
Collapse
Affiliation(s)
- Catherine M Rawlins
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA, USA.
| | - Joseph P Salisbury
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA, USA.
| | - Daniel R Feldman
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Sinan Isim
- Life Sciences Department, Brandeis University, Waltham, MA, USA.
| | - Nathalie Y R Agar
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Ed Luther
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA.
| | - Jeffery N Agar
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA, USA. .,Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|