Open AccessThree-Dimensional Imaging with Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry
Author(s) -
Hongxia Bai,
Sitora Khodjaniyazova,
Kenneth P. Garrard,
David C. Muddiman
Publication year - 2019
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1021/jasms.9b00066
Subject(s) - chemistry , mass spectrometry , desorption electrospray ionization , mass spectrometry imaging , matrix assisted laser desorption electrospray ionization , laser , analytical chemistry (journal) , infrared , resolution (logic) , ionization , desorption , matrix assisted laser desorption/ionization , optics , chromatography , thermal ionization mass spectrometry , ion , artificial intelligence , computer science , physics , organic chemistry , adsorption
Mass spectrometry imaging as a field has pushed its frontiers to three dimensions. Most three-dimensional mass spectrometry imaging (3D MSI) approaches require serial sectioning that results in a loss of biological information between analyzed slices and difficulty in reconstruction of 3D images. In this contribution, infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) was demonstrated to be applicable for 3D MSI that does not require sectioning because IR laser ablates material on a micrometer scale. A commercially available over-the-counter pharmaceutical was used as a model to demonstrate the feasibility of IR-MALDESI for 3D MSI. Depth resolution (i.e., z-resolution) as a function of laser energy levels and density of ablated material was investigated. The best achievable depth resolution from a pill was 2.3 μm at 0.3 mJ/pulse. 2D and 3D MSI were performed on the tablet to show the distribution of pill-specific molecules. A 3D MSI analysis on a region of interest of 15 × 15 voxels across 50 layers was performed. Our results demonstrate that IR-MALDESI is feasible with 3D MSI on a pill, and future work will be focused on analyses of biological tissues.