Thermogravimetric analysis (TGA) and Fourier transform-infrared spectroscopy (FT-IR) techniques for water content determination were compared with a neutron characterization technique, prompt gamma activation analysis (PGAA). Residual H content in the samples, heat treated at various temperatures, was measured with PGAA and compared with the results obtained from TGA. Two major difficulties in TGA were overlapping of mass loss regimes due to removal of different species and residual water that could not be removed, even though the samples were heated above 900 degrees C. After 3 h of heat treatment at 900 degrees C, 0.007% mass fraction H remained in the sample. FT-IR spectra confirmed the presence of H semiquantitatively. It is concluded that residual H remains even after high-temperature treatments.