Ambient molecular imaging of dry fungus surface by electrospray laser desorption ionization mass spectrometry

Ambient molecular imaging by Electrospray Laser Desorption/Ionization Mass Spectrometry (ELDI/MS) is described. The sample is sliced and placed onto the sample plate without further pretreatment. The distinctive distribution of the predominant chemical compounds on the surface of two dry fungi (Ganoderma lucidum and Antrodia camphorata) was obtained. Molecular images of hard and thick fungus slices were obtained for the first time, and both volatile and nonvolatile compounds originated from fungi were detected. The effects of the pulse laser frequency and the speed of the movement of the sample stage on the image quality were also investigated. (C) 2012 Elsevier B.V. All rights reserved.