FTIR spectra showing the characteristic TiChu OH bands. Fluorine concentration increases towards the lower spectra. As F increases, the relative heights of 3,565 and 3,528 change, as well as the height of the large peaks around 3,400 to 3,390. From these observations, at a first order, F-rich and F-poor TiChu are easily identified by their FTIR spectra in OH regions. For clarity, the spectra are ordinate-shifted.