Modern Instrumental Methods for Analysis of Soluble Silicates

Abstract

Modern analytical instrumentation has been used in the last 25 years for determining commercially important characteristics of soluble silicates, and the nature of silicate species in silicate glasses and solutions. The classical wet methods for assay of silicate solutions are alkali titration and gravimetric determination of silica, which can also be determined, with lesser precision, by the alkali fluosilicate method. The alternative instrumental assay methods, X-ray fluorescence, atomic spectroscopy and thermotitrimetry, will be compared with the classical methods for precision and ease of measurement. Instrumental methods have greatly extended the ability of the analyst to detect trace cations and anions in soluble silicates. The scope and limitations, illustrated by some applications, of atomic and X-ray fluorescence spectroscopy, ion selective electrodes, and other less common methods for impurity analysis will be discussed. The techniques of infrared, Raman, X-ray photoelectron, and sputter induced photon spectroscopy, used for identification of silicate species will be briefly reviewed.