Determination of low specific surface areas of minerals and oxides by gas–solid chromatography

Abstract

Gas–solid chromatography is shown to provide a method for measuring the specific surface area of non-porous particulate mineral or oxide samples in the range 0.005 to 0.5 m2 g−1 with precision as high as ±10%. Mesitylene is a convenient sorbate and was found to occupy an area of 71 ± 5 Å2 per molecule on silicate surfaces, by calibration with glass particles having well defined surface geometries. The rather low values obtained for the C parameter, when fitting retention volume data to the BET equation, suggest that the area occupied by mesitylene may be affected by the surface on which it is adsorbed. Hydrocarbon contaminants are a major interference. No specialized instrumentation is required.