title: Parameters for the adsorption of thallium ions by activated charcoal and Prussian blue.
abstract: Activated charcoal and Prussian blue are effective antidotes in acute thallium (T1+) intoxication in rats. They act by trapping any metal present in or secreted into the gut by the gastro-intestinal epithelium. It was therefore of interest to determine the parameters of the Langmuir adsorption isotherms of T1+ ions for these two adsorbents. The data from equilibration experiments were analyzed by direct least-squares fitting to a hyperbola and with Langmuir's equation to give the following results: Activated charcoal: K1(-1) = 192 micrograms ml-1, K2 = 124 mg g-1 Prussian Blue: K1(-1) = 130 micrograms ml-1, K2 = 72 mg g-1. These high values provide in vitro confirmation of their in vivo antidotal efficacy and show that activated charcoal can replace Prussian blue when this latter drug is unobtainable.
mesh_terms: D000327:Adsorption; D002606:Charcoal; D005295:Ferrocyanides; D008433:Mathematics; D008956:Models, Chemical; D013793:Thallium
chemical_list: D005295:Ferrocyanides; D002606:Charcoal; D013793:Thallium; C000170:ferric ferrocyanide