Novel Ion Extraction Method for Imaging Mass Spectrometry

Abstract

We have developed a new ion extraction method for a stigmatic matrix-assisted laser desorption/ionization (MALDI) imaging time-of-flight (TOF) mass spectrometer. The conventional delayed extraction method is unsuitable for a stigmatic imaging TOF mass spectrometer because the ions disperse until extraction and the ion distribution is not preserved for imaging. In the proposed method, temporal and spatial focusing can be simultaneously achieved, enabling a high-fidelity image to be obtained with a high mass resolution. This method is expected to be applicable to cellular-level observations by imaging mass spectrometry.