An x-ray scattering investigation of the carbonization of olive stones

The X-ray spectra scattered by olive stones and the corresponding carbonization products obtained up to 800 degrees C have been determined. The observed Compton intensity is in prominence in relation to the Rayleigh intensity, as a consequence of the chemical composition of the materials, where light (low atomic number) elements predominate. Since carbonization implies a considerable loss of carbon, hydrogen and oxygen, and consequently a decrease in the number of scattering entities per unit volume, there is a decrease in the Compton and Rayleigh intensities (I-C and I-R) with increasing temperature of the carbonization process. However, the I-R/I-C ratio is kept constant for all samples resulting from carbonization. Consequently, the original precursor as well as the carbonized materials constitute a solid matrix insensitive to the changes in the I-R/I-C ratio, and this may be very useful when quantitative determination of heavy atoms deliberately incorporated to the carbon material is needed. (C) 1997 Elsevier Science Ltd.