Effect of Unitary, Binary and Ternary Carboxylates on Crystallization Kinetics of Calcium Oxalate in Artificial Urine

The effect of three types of carboxylates on the crystallization kinetics of calcium oxalate (CaC2O4) were studied by detecting the change of free Ca2+ ions concentration, size of CaC2O4 crystallites, zeta potential, autocorrelation curve and decay time with reaction time (t) in artificial urine. Sodium glycinate (NaGly; a monocarboxylate), sodium tartrate (Na(2)Tart; a dicarboxylate) and sodium citrate (Na(3)Cit; a tricarboxylate) were the three carboxylates investigated in this study. The crystallization kinetics equation of CaC2O4 was r = kc(3.3) and the average reaction rate constant ((k) over bar) was 0.99 x 10(9). All the three carboxylates could inhibit the kinetics process of nucleation, growth and aggregation of CaC2O4 crystallites. In the presence of various carboxylate, the value is arranged from smallest to largest in the following order Na(3)Cit (2.29 x 10(5)) < Na(2)Tart (9.76 x 10(5)) < NaGly (1.68 x 10(7)) < Blank (0.99 x 109). The changes in size, zeta potential and decay time of the crystallites can also be arranged in the following order: Na(3)Cit < Na(2)Tart < NaGly < blank.