Depth Profiling of a Photochemically Yellowed Paper. Part II: FT-IR Techniques

A strongly photo-yellowed paper, whose surface had been ground off to different depths, was subjected to various Fourier transform infrared (FT-IR) techniques, including attenuated total reflectance (ATR), diffuse reflectance (DRIFT), photoacoustic (PA), and potassium bromide pellet (KBr) spectroscopy. Depth profiling of the paper was accomplished by monitoring specific infrared bands which showed systematic and consistent changes caused by irradiation. The results from the different Fourier transform infrared techniques were compared.