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PubMed · 15952713

Infrared mass spectrometric imaging below the diffraction limit.

Stefan L Luxembourg·Liam A McDonnell·Todd H Mize·Ron M A Heeren
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Abstract

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)1 is an established technique for the analysis of biological macromolecules. Its relative insensitivity to pollutants makes MALDI-MS very suitable for the direct analysis of biological samples. As such, it has facilitated great advances in the field of biomolecular imaging mass spectrometry. Traditionally, MALDI-MS imaging is performed in a scanning microprobe methodology.(2-4) However, in a recent study we have demonstrated an alternative methodology; the so-called microscope mode,(5) where the requirement for a highly focused ionization beam is removed. Spatial details from within the desorption area are conserved during the flight of the ions through the mass analyzer, and a magnified ion image is projected onto a 2D-detector. In this paper, we demonstrate how imaging mass spectrometry benefits from the microscope mode approach. For the first time, high-lateral resolution ion images were recorded using infrared MALDI at 2.94 microm wavelength. The ion optical resolution achieved was well below the theoretical limit of (light-) diffraction for the setup used, which is impossible to achieve in the conventional scanning microprobe approach.

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Infrared RaysLasersMicroscopySpectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationJournal Article

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Stefan L Luxembourg, Liam A McDonnell, Todd H Mize, Ron M A Heeren. Infrared mass spectrometric imaging below the diffraction limit.. https://doi.org/10.1021/pr049762%2B

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