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The present study investigates the adsorption of fourcompoundsimportant in carbon adsorption hemoperfusion. Graphite nanofibers(GNFs) having different carbon plane orientations have structuralfeatures that make them potentially attractive in this applicationcompared to activated carbon. Generally, adsorption capacity increasedin the order of ribbon > herringbone > platelet fiber types.All fiberswere poor adsorbents for creatinine. Herringbone and platelet fibershad sorption capacities less than 25% of activated carbon for alladsorbates on a mass basis. Except for vitamin B12, behavior of ribbonfibers was similar; vitamin B12 adsorption was nearly 50% greaterthan activated carbon on a mass basis. In contrast, on the basis ofsurface area, all of the fibers were comparable to or outperformedactivated carbon for the adsorption of all adsorbates. This suggeststhat in addition to BET surface area, interactions between adsorbateand exposed basal planes in carbon are important in determining adsorptioncapacity. Chemical treatment with hydrochloric acid or with urea followedby thermal treatment did not significantly change the fiber surfacearea, micropore volume, or equilibrium adsorption. Nitric acid treatmentof herringbone and ribbon fibers slightly decreased the surface areabut did not enhance adsorption, whereas this treatment degraded plateletfibers. [ABSTRACT FROM AUTHOR]