Removal of albumin-bound toxins from albumin-containing solutions: Tryptophan fixed-bed adsorption on activated carbon

Fixed-bed adsorption on activated carbon is a common blood detoxification technique implemented in liver support devices to remove different types of toxins, among which is tryptophan. In this paper, fixed-bed adsorption kinetics of tryptophan on activated carbon were investigated. Experimental tryptophan breakthrough curves were obtained at different feed flow rates, both in albumin-free and albumin-containing solutions. A mathematical model based on linear driving force mass transfer kinetics was used to correlate data obtained with albumin-free solutions; subsequently, the results were successfully used to predict tryptophan breakthrough curves obtained with albumin-containing solutions, accounting only for the effect of albumin over tryptophan adsorption equilibrium. (C) 2009 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.