Saline cathartics and the adsorptive capacity of activated charcoal for aspirin

The influence of three saline cathartics and tap water on the adsorption characteristics of activated charcoal for aspirin was studied with adsorption isotherms. Compared with distilled water, the adsorptive capacity of activated charcoal for aspirin was not significantly altered by magnesium sulfate, sodium sulfate, or tap water. Pretreating activated charcoal with magnesium citrate reduced the adsorptive capacity of activated charcoal by 15% (P less than .05). There was no significant correlation between mean pH values and adsorptive capacities in all test solutions. None of the saline cathartic solutions apparently displaced aspirin that already was adsorbed by activated charcoal.