High-precision frequency measurements: indispensable tools at the core of the molecular-level analysis of complex systems.

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  • Norbert Hertkorn
  • Christoph Rücker
  • Markus Meringer
  • Ralf Gugisch
  • M. Frommberger
  • E.M. Perdue
  • M. Witt
  • Philippe Schmitt-Kopplin
This perspective article provides an assessment of the state-of-the-art in the molecular-resolution analysis of complex organic materials. These materials can be divided into biomolecules in complex mixtures (which are amenable to successful separation into unambiguously defined molecular fractions) and complex nonrepetitive materials (which cannot be purified in the conventional sense because they are even more intricate). Molecular-level analyses of these complex systems critically depend on the integrated use of high-performance separation, high-resolution organic structural spectroscopy and mathematical data treatment. At present, only high-precision frequency-derived data exhibit sufficient resolution to overcome the otherwise common and detrimental effects of intrinsic averaging, which deteriorate spectral resolution to the degree of bulk-level rather than molecular-resolution analysis. High-precision frequency measurements are integral to the two most influential organic structural spectroscopic methods for the investigation of complex materials—NMR spectroscopy (which provides unsurpassed detail on close-range molecular order) and FTICR mass spectrometry (which provides unrivalled resolution)—and they can be translated into isotope-specific molecular-resolution data of unprecedented significance and richness. The quality of this standalone de novo molecular-level resolution data is of unparalleled mechanistic relevance and is sufficient to fundamentally advance our understanding of the structures and functions of complex biomolecular mixtures and nonrepetitive complex materials, such as natural organic matter (NOM), aerosols, and soil, plant and microbial extracts, all of which are currently poorly amenable to meaningful target analysis. The discrete analytical volumetric pixel space that is presently available to describe complex systems (defined by NMR, FT mass spectrometry and separation technologies) is in the range of 108–14 voxels, and is therefore capable of providing the necessary detail for a meaningful molecular-level analysis of very complex mixtures. Nonrepetitive complex materials exhibit mass spectral signatures in which the signal intensity often follows the number of chemically feasible isomers. This suggests that even the most strongly resolved FTICR mass spectra of complex materials represent simplified (e.g. isomer-filtered) projections of structural space.
Translated title of the contributionHochpräzisions-Frequenzmessungen: unentbehrliche Werkzeuge am Kern der Analyse des molekularen Level von komplexen Systemen.
Original languageEnglish
JournalAnalytical & Bioanalytical Chemistry
Issue number5
Pages (from-to)1311-1327
Number of pages17
Publication statusPublished - 11.2007
Externally publishedYes

Bibliographical note

This work was partly supported by the Zhejiang Provincial Natu- ral Science Foundation of China (Grant No. LY15F010003 and No. LY14F020024), the Public Good Research Project of Science and Technology Program of Zhejiang Province, China. (NO.2016C31097), the Science and Technology Project of QuZhou, Zhejiang, China.(NO.2015Y005), the Project for Visiting Scholars' Professional Development in Universities of Zhejiang Province, China (No.FX2014102),the Project for Young Aca- demic Leaders' Academic Promotion in Colleges and Universities of Zhejiang Province, China(No. pd2013450), and the Natural Science Foundation of Zhejiang Province, China (No. LY15F020041).

    Research areas

  • Chemistry
  • Complex systems, Complexity, Compositional space, FT mass spectrometry, Intrinsic averaging, Isomers, NMR, Resolution, Separation