Spectroscopic control of iron oxide dissolution in two ferralitic soils

摘要: Summary Second derivative diffuse reflectance spectroscopy (DRS) in the visible range has been used to characterize changes colour and identify nature of Fe oxides which withstand reduction during experimental yellowing reddish materials. It is accepted that haematite dissolves preferentially faster than goethite, Al-substitution controls dissolution kinetics oxides. However, DRS shown more resistant predicted some Fe-oxides, probably trapped within kaolinite particles, are inaccessible solvents. allows dissolved phases at each deferration step be determined Al-content residual throughout followed. also demonstrated Helmholtz coordinates correlate very well with Fe-oxide mineralogy preferable redness ratings when monitoring differential through measurements. a powerful sensitive technique for soils.