LEAD PHOSPHATE HYDROXYAPATITE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Spherical aggregates of lead phosphate hydroxyapatite (PbHA) have been developed as an adsorbent in high-performance liquid chromatography. There are effectively two types of crystal surface, a (or b) and c which appear on the crystal, analogous to the case of calcium phosphate hydroxyapatite. Basic proteins adsorb to the c surface, and can be eluted by chloride or phosphate salts. Acidic proteins adsorb to the a (or b) surface, and are eluted only by phosphate. All proteins were adsorbed at pH 6 and eluted at pH 8-10. The binding capacity of PbHA for bovine serum albumin was determined by frontal analysis; the shape of the adsorption isotherm is of the Langmuir type.