Crystallization kinetics of calcium oxalate monohydrate in the presence of amino acids

Abstract

Studied is the effect of L-aspartic acid (L-Asp), L-arginine (L-Arg) and L-threonine (L-Thr) on the crystallization kinetics of calcium oxalate monohydrate (COM). L-Asp and L-Arg amino acids exert an inhibitory effect on COM crystallization. Addition of 1-20 mM of L-Asp and L-Arg to the calcium oxalate model system increases the induction time in comparison with that of pure COM by 3-10 and 1.3-6 times, respectively. The degree of inhibition of COM crystallization is 86.0 % (for 20 mM of L-Arg) and 90.2 % (for 20 mM of L-Asp) due to high adsorption capacity of these molecules on COM crystal faces. L-Thr amino acid is a promoter of COM crystallization; the induction time is reduced by 2 times as against that of pure microcrystals.