Significance of critical photon density in the multi-photon process in laser desorption ionization using ultra-high resolution FT-ICR MS

摘要

Ultra-high-resolution mass spectra of butane flame soot were obtained using laser desorption ionization (LDI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Two major ion groups showing different laser power dependence were observed. Organic ions initially formed at a low laser power, after which carbon cluster ions were generated at laser powers above a specific threshold. We observed different critical photon density for multi-photon process (CPDMPP) values for each ion group. By adjusting the laser photon density between the two CPDMPP values, organic ions were selectively observed (excluding carbon cluster ions from soot) for the first time. (C) 2015 Elsevier B.V. All rights reserved.