PYROPHOSPHATES AS BIOCOMPATIBLE PACKING MATERIALS FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Crystalline pyrophosphates of Mg, Ca, Sr, Mn and Zr were developed as new packing materials for high-performance liquid chromatography. They were synthesized as porous and rigid spheres based on a spray-pyrolysis method, followed by heat treatment. The pyrophosphate (PPi) packing materials thus obtained had high mechanical strength. All PPi columns tested showed similar chromatographic behaviours of basic proteins. In contrast, the chromatographic behaviour of acidic proteins, nucleotides and nucleic acids depended on the kind of PPi column: beta-Ca2P2O7, alpha-Sr2P2O7 and Mn2P2O7 columns showed similar chromatographic behaviour, whereas beta-Mg2P2O7 and ZrP2O7 columns showed no retention of most acidic proteins including phosphoproteins. Based on this property, a successful single-step separation of gamma-globulin from other serum proteins by the beta-Mg2P2O7 column was achieved. The beta-Mg2P2O7 column could not retain nucleotides and the ZrP2O7 column could not retain nucleic acids.