Two-dimensional partial covariance mass spectrometry of large molecules based on fragment correlations
| Autor: | Serguei Patchkovskii, Ruth Ayers, Taran Driver, Leszek J. Frasinski, Jon P. Marangos, Rüdiger Pipkorn, Vitali Averbukh, B. D. Cooper, Marina Edelson-Averbukh, David R. Klug |
|---|---|
| Přispěvatelé: | Engineering & Physical Science Research Council (EPSRC), EPSRC/DSTL, Wellcome Trust |
| Rok vydání: | 2020 |
| Předmět: |
IONS
QC1-999 Physics Multidisciplinary 0204 Condensed Matter Physics General Physics and Astronomy Proteomics Mass spectrometry 01 natural sciences Spectral line Mass Spectrometry 010305 fluids & plasmas Ion Analytical Chemistry Fragmentation (mass spectrometry) 0103 physical sciences 0201 Astronomical and Space Sciences Molecule SPECTRA PEPTIDE 010306 general physics 0206 Quantum Physics chemistry.chemical_classification Quantitative Biology::Biomolecules Science & Technology Chemical Physics Quantitative Biology::Molecular Networks Biomolecule Physics DISSOCIATION Covariance chemistry Chemical physics Physical Sciences IONIZATION PROTEOMICS Chemistry Analytic |
| Zdroj: | Physical Review X, Vol 10, Iss 4, p 041004 (2020) |
| ISSN: | 0036-8075 |
| Popis: | Covariance mapping [L. J. Frasinski, K. Codling, and P. A. Hatherly, Science 246, 1029 (1989)SCIEAS0036-807510.1126/science.246.4933.1029] is a well-established technique used for the study of mechanisms of laser-induced molecular ionization and decomposition. It measures statistical correlations between fluctuating signals of pairs of detected species (ions, fragments, electrons). A positive correlation identifies pairs of products originating from the same dissociation or ionization event. A major challenge for covariance-mapping spectroscopy is accessing decompositions of large polyatomic molecules, where true physical correlations are overwhelmed by spurious signals of no physical significance induced by fluctuations in experimental parameters. As a result, successful applications of covariance mapping have so far been restricted to low-mass systems, e.g., organic molecules of around 50 daltons (Da). Partial-covariance mapping was suggested to tackle the problem of spurious correlations by taking into account the independently measured fluctuations in the experimental conditions. However, its potential has never been realized for the decomposition of large molecules, because in these complex situations, determining and continuously monitoring multiple experimental parameters affecting all the measured signals simultaneously becomes unfeasible. We introduce, through deriving theoretically and confirming experimentally, a conceptually new type of partial-covariance mapping—self-correcting partial-covariance spectroscopy—based on a parameter extracted from the measured spectrum itself. We use the readily available total ion count as the self-correcting partial-covariance parameter, thus eliminating the challenge of determining experimental parameter fluctuations in covariance measurements of large complex systems. The introduced self-correcting partial covariance enables us to successfully resolve correlations of molecules as large as 10^{3}–10^{4} Da, 2 orders of magnitude above the state of the art. This opens new opportunities for mechanistic studies of large molecule decompositions through revealing their fragment-fragment correlations. Moreover, we demonstrate that self-correcting partial covariance is applicable to solving the inverse problem: reconstruction of a molecular structure from its fragment spectrum, within two-dimensional partial-covariance mass spectrometry. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|