The effect of different kinds of potassium carboxylates on the crystallization of calcium oxalate (CaC₂O₄) was investigated in silica gel system by means of scanning electron microscopy and X-ray diffraction. The investigated potassium carboxylates included: monocarboxylate potassium acetate (KOAc), dicarboxylate potassium tartrate (K₂Tart), tricarboxylate potassium citrate (K₃Cit), and tetracarboxylate dipotassium of ethylenediaminetetraacetic acid (K₂EDTA). KOAc can only induce calcium oxalate monohydrate (COM), while K₃Cit and K₂EDTA induce COM and calcium oxalate dihydrate (COD). The ability of multicarboxylates to induce COD formation was increased with increasing their concentrations. Calcium oxalate trihydrate (COT) was induced by K₂Tart. As the crystallization temperature was decreased, the percentage of COD crystals increased, the surface area of COM crystals decreased, but the percentage of COT crystals induced by K₂Tart decreased. Since both increasing the content of COD or COT and decreasing the surface area of COM crystals favor the inhibition of CaC₂O₄ stones, potassium multicarboxylates can be used to prevent and cure this disease.

Key words: calcium oxalate, potassium carboxylate, urinary stone