A New Approach to the Spectrochemical Analysis of Silicate Rocks and Minerals

Abstract

The effect of major components of silicate rocks and minerals, Al, Ca, Fe, K, Mg, and Na, on the common trace elements in a dc arc plasma was investigated by measuring plasma parameters such as volatilization rate, temperature, electron density, and electric field strength in matrices consisting of SiO₂ with and without the major components. Identical behavior of these parameters in the synthetic mixtures and pure SiO₂ occurs only in the central portion (≈2 mm) of the arc plasma. Common petrological types of silicates were analyzed against standards in pure SiO₂ for the common trace element assemblage. Internal standards can be discarded, and coefficients of variation of approximately 15% were obtained for all trace elements analyzed.