SPECTROCHEMICAL ANALYSIS OF ARCHAEOLOGICAL TERRA-COTTA SAMPLES AND CLAY-MINERALS USING ICP-AES

A simple method for the multi-element analysis of terra-cotta samples and clay minerals by inductively coupled plasm-atomic emission spectro metry (ICP-AES) is described. Major and minor elements were determined by sequential ICP-AES. The effect of changes in radio frequency power on net intensities of the various spectral lines was studied. The sam ples were decomposed by fusion and the method was tested by determinin g Si, Al, Fe, Ca, Mg, Mn, Pb, Cu, Zn, Ti, and Na in the standard solut ion and in U.S. Geological Survey reference material GXR-3. Good agree ment with certified values was obtained. The precision of the determin ations (RSD) ranged from 0.4-2-5% which depended on the element and it s concentration.