Inhibition of Struvite Crystallization by Tetrasodium Pyrophosphate in Artificial Urine: Chemical and Physical Aspects of Nucleation and Growth

The effect of tetrasodium pyrophosphate on struvite nucleation and growth in the context of infectious urinary stone formation is studied. The crystallization processes occurred in artificial urine, while urease activity was simulated in a chemical way. The spectrophotometric results show that the presence of tetrasodium pyrophosphate causes a delay of struvite nucleation and decrease in growth efficiency. These results are explained on the basis of theoretical chemical speciation analysis of different complexes formed in artificial urine. The obtained results clearly show that the formation of the MgP2O72– complex plays the most important role in inhibition of struvite nucleation. It has been also found that tetrasodium pyrophosphate causes changes in struvite morphology and habit.