Use of an internal standard with differential X-ray diffraction analysis for iron oxides.

In the differential X-ray diffraction (DXRD) method the diffraction pattern for iron minerals in a soil or clay sample is obtained by subtracting the pattern for a sample free of iron oxides, after appropriate adjustment of intensity, from that of an untreated sample. We modified this method by using alumina as an internal standard to calculate the scale factor for the adjustment of intensity. The internal standard also serves as a reference for making corrections in peak position.-from Authors