Analysis of free-electron laser-induced infrared multiphoton dissociation for cholesterol ester

Free-electron lasers (FELs) have been developed as tunable lasers over a wide range of wavelengths. Devices radiating in the mid-IR, visible and UV are operable in the Free Electron Laser Research Institute at Osaka, Japan. Under IR radiation by FEL, successful selective IR multiphoton dissociation (IR MPD) of cholesterol ester has been performed for the first time. Upon irradiating the ester in the spectral region of the >CO ester stretching band at 1740 cm−1, cholesterol ester was partially dissociated. FTIR and proton NMR measurements supported the results. Visually, the point of dissociation was clearly observed.