Determination of impurities in titanium disilicide by inductively coupled plasma atomic emission spectrometry after acid decomposition

Abstract

In order to determine impurities (eleven elements) in titanium disilicide (TiSi₂) by inductively coupled plasma atomic emission spectrometry (ICP-AES), a sample dissolution procedure using acids was examined. A TiSi₂ powder sample was decomposed with sulfuric acid, nitric acid and hydrofluoric acid in a PTFE beaker. The mixture was filtered, and the small amount of residue on the filter-paper was ashed in a platinum crucible. The ashed residue was transferred into a PTFE pressure vessel with sulfuric acid, nitric acid and hydrofluoric acid and decomposed under pressure at 180 °C. The filtrate and the residue solution were collected in a calibrated flask. The matrix effects on the background levels and the emission intensities of the elements were compensated by using matrix-matched standard solutions for calibration. Eleven elements (Al, Ca, Co, Cr, Fe, Mg, Mn, Na, Sr, W and Zr) in commercial TiSi₂ powder samples were determined with good precision. For most elements, the values obtained by the proposed method were found to be in good agreement both with those obtained by the proposed method with atomic absorption spectrometry and those obtained by the use of the fusion method using sodium carbonate with ICP-AES. The detection limits were 0.03 µg g^–1 for Sr to 5.6 µg g^–1 for W.