Quantitative Determination of High Charge Density Polyanion Contaminants in Biomedical Heparin Preparations Using Potentiometric Polyanion Sensors.

Quantification of oversulfated chondroitin sulfate (OSCS) in biomedical heparin preparations is achieved using a recently described potentiometric polyanion sensor-based approach operated in a kinetic mode of analysis. This is accomplished by adjusting the concentration of the test sample to a range where the OSCS level is low enough for the sensor not to achieve a full and rapid equilibrium phase boundary potential change at the membrane/sample interface upon exposure to the heparin sample. Using this method, the OSCS wt% determined within heparin samples containing OSCS are shown to be in good agreement with those determined by an accepted NMR method.