FLUORIDE-MODIFIED ZIRCONIUM-OXIDE AS A BIOCOMPATIBLE STATIONARY PHASE FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Previously we found that porous microparticulate zirconium oxide strongly adsorbs fluoride from aqueous solutions. The adsorption is due in large part to a Lewis acid-base interaction between coordination sites on the zirconium oxide surface and fluoride. The resulting complex is very stable relative to many other species and therefore fluoride is hard to displace. The chromatographic properties of small molecules and proteins on zirconium oxide particles when fluoride is present in the mobile phase is investigated in this work. In the presence of fluoride, zirconium oxide is a very biocompatible adsorbent, the selectivities of which are analogous to those of calcium hydroxyapatite. The effect of fluoride is very reproducible even after the adsorbed fluoride is stripped by strong base and regenerated in fluoride buffer.