The chromatographic technique which employs SPSC and takes into account the extra-column effects of the measuring system can provide consistent transport characteristics of porous solids. These characteristics are independent of the kind of gases which are transported through pores, as well of temperature and pressure. Dispersion of the tracer band in the interparticle spaces of the SPSC increases at higher carrier gas velocities when the non-porous column packing is replaced by a porous one. This points to some additional mechanism of band spreading caused by the presence of interface gas-porous solid.