Packing material for liquid chromatography

Abstract

Column packing materials useful in applications such as liquid chromatography, as well as a process for producing such a packing material are described. A first aspect of the invention concerns a column packing material composed of a spherical substrate having a coating of a calcium phosphate based compound on the surface thereof. A second aspect of the invention concerns a packing material comprising porous calcium phosphate based granules having open pores with an average pore size of from 0.01 to 20 mu m, said granules being composed of crystalline particles with an average size of from 0.1 to 10 mu m. A third aspect of the invention concerns a spherical packing material for liquid chromatography comprising spherical particles of at least one material selected from the group consisting of Ca10(PO4)6(OH)2, Ca3(PO4)2, Ca2P2O7, Ca(PO3)2, Ca10(PO4)6F2 and Ca10(PO4)6Cl2, said packing material having a dense structure with a porosity of no more than 5%. A fourth aspect of the invention concerns a packing for liquid chromatography comprising particles having at least on the surface thereof a fluoroapatite represented by formula (I): Ca10(PO4)6(OH)2-2xF2x (I) wherein x is a number of from about 0.1 to 1.

What is claimed is: 
     
       1. A packing for liquid chromatography comprising .[.particles having.]. fluoroapatite .[.represented by formula (I) throughout the particle structure:   Ca.sub.10 (PO.sub.4).sub.6 (OH).sub.2-2x F.sub.2x          (I)     wherein x is a number of from about 0.1 to 1.]. .Iadd.particles.Iaddend.;   wherein said particles are obtained by a process comprising the steps of:   .[.producing.]. .Iadd.providing .Iaddend.a fluoroapatite .[.of formula I.]. .Iadd.particles.Iaddend.;   .[.forming said fluoroapatite into particles;.]. and   firing said particles at a temperature of from 900° C. to 1,400° C. to obtain .[.homogeneous.]. particles having open pores with average .[.pore.]. pore size of from 0.01 to 20 μm. .[.   
     
     
       2.  A packing for liquid chromatography as claimed in claim 1, wherein said particles have an average particle diameter of from about 1 to 100 μm..]..[.3. A packing for liquid chromatography as claimed in claim 1, wherein said particles have an average particle diameter of from about 2 
     
     
        to 100 μm..]..[.4.  A packing for liquid chromatography as claimed in claim 3, wherein said particles have an average particle diameter of from about 2 to 10 μm..]..[.5. A packing for liquid chromatography as claimed in claim 3, wherein said particles have an average particle diameter of from about 10 to 100 μm..]..[.6. A packing for liquid chromatography as claimed in claim 3, wherein said particles have a shape 
     
     
        that is approximately spherical..].7. A packing for liquid chromatography as claimed in claim 1, wherein said .Iadd.porous .Iaddend.particles .[.have open pores with an average pore size of from 0.01 to 20 μm, said particles.]. are composed of crystalline particles with an average size of from 0.1 to 10 μm.