This study used CrO 3-loaded silica as an example to illustrate how the hydration of the samples could affect the structural parameters of an environmental sample. Our results showed that as the moisture content in samples increased, the amplitude of the EXAFS increased, while the oscillation frequency of the EXAFS was virtually unchanged. The hydration of Cr(VI) enhanced the first-shell coordination number (Cr-O); the Debye-Waller factor was also changed. The first-shell coordination number was 4.55 for CrO 3-loaded silica slurry and 2.67 for the dry CrO 3-loaded silica. The Debye-Waller factor (σ 2) was 0.0036 for the slurry and 0.0014 for the dry one. In addition, hydration caused a considerable change in the pre-edge height and the white band of the XANES spectra of Cr(VI). ? Physica Scripta 2005.
