ABSTRACT
Finally, a correction for the contribution of DP to De was made [Eq. (32)], allowing the derivation of D8 from De. The error made on the estimate of DP also influences the accuracy of the value of D8 • We calculated DP from Dm, Ep, and k, according to the parallel pore model [20]. In such a case, the uncertainty in the estimate of DP is proportional to that of Dm [Eq. (33)]. As indicated later in this review, the contribution of the surface diffusion to the overall mass-transfer resistance in RP packing materials is high, usually as much as ~ 85-95% or more. Because surface diffusion turns out to have an extremely dominant role in intraparticle diffusion, the influence of the error made on the estimate of DP on the determination of D8 is negligible. On the basis of the considerations discussed here, we can conclude that the error made on Ds was probably of the order of 510%.
