Titrimetric and gravimetric determination of the specific pore volume of microparticulate silica gels

Abstract

The titrimetric and gravimetric methods of determination of the specific pore volume were studied unmodified and modified chromatographic silica gels of mean particle size above 5 μm. The apparatus and titrimetric procedure suggested elsewhere were adapted so that the relative standard deviation of measurement did not exceed 2%. Water, n-octane, and methanol were used as titrants, and methanol was found to suit best from the point of view of accuracy and rapidity of analysis and versatility of use. This solvent is also suitable for the gravimetric measurements, which can be carried out without thermostatting and at barometric pressure. The titrimetric procedure is less time consuming than the gravimetric procedure which, on the other hand, is less tedious and less instrumentation-demanding.