Abstract

Fundamental Sessions

Day 3, June 12（Wed.）　9:33-9:51　Room D (Conference Room 202)

Fatty acids present in the body include free fatty acids and fatty acids contained in lipids such as phospholipids and triglycerides. When attempting to detect free fatty acids by MALDI mass spectrometry imaging, it was difficult to distinguish endogenous free fatty acids from fatty acids as fragment ions because fragment ions of fatty acids derived from phospholipids and triglycerides are produced during ionization. Therefore, by derivatizing free fatty acids on tissue sections and converting them to quaternary amines prior to ionization, we were able to clarify the distribution of endogenous free fatty acids. Endogenous carboxylic acids present in the mouse digestive tract were converted to quaternary amines by condensation on tissue with TMPA (N,N,N trimethyl-2-(piperazin-1-yl)ethan-1-aminium iodide ) and visualized by MALDI imaging mass spectrometry. The mixed reagents for derivatization were automatically applied by iMLayer ™ AERO and then incubated in acetonitrile vapor at 23°C for 4 hours. The matrix was then deposited by sublimation and imaging mass spectrometry was performed in positive mode. Endogenous short and long chain carboxylic acids were detected with high sensitivity at 10 micrometer spatial resolution.

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