MS Imaging of Low Molecular Weight Metabolites Using a Sublimation/Recrystallization Method with 9-Aminoacridine (9AA)

Introduction

MS imaging technology initially appeared in the first half of the 1980s and has continued to undergo technological innovation to the present day. It is used in a wide variety of fields including drug discovery and metabolomics research. Technological improvements are still being pursued to this day to enhance capabilities including sensitivity, spatial resolution, and repeatability. Although various matrices that employ ionization have been developed over the years, it is important to select the matrix appropriate for the targeted compound. In addition to matrix selection, the coating method also has a significant effect on analysis results. Consequently, a number of coating methods appropriate for the targeted compound have been examined. These are broadly divided into the spray method and the sublimation method, and since each method has its advantages and disadvantages, currently both are widely used. Shimadzu has developed the iMLayer matrix vapor deposition system employing the sublimation method (Fig. 1), which can control the matrix coating thickness. Matrix coating methods have been further examined using this instrument. This article introduces a sublimation/recrystallization method we developed for 9AA, with which recrystallization was previously said to be difficult. Examples of MS imaging using this method are also introduced for low molecular weight metabolites (LMWMs) in a mouse liver.

December 12, 2017 GMT