The Effect of Amino Acids on the Polymorphic Crystallization of Calcium Carbonate

Abstract

<p> The presence of 0.10 moles/l. of glycine, glutamic acid, aspartic acid or leucine in a saturated bicarbonate solution will promote the formation of aragonitic calcium carbonate at 25.2°C. Magnesium ion, with or without an amino acid, also promotes the formation of aragonite. With increased amino acid concentration glutamic acid and alanine tend to promote the formation of more calcitic calcium carbonate, glycine and valine tend to promote the formation of more aragonitic calcium carbonate. Lysine and alanine show an increased tendency to form calcite at higher ionic strengths (.20) whereas glutamic acid shows the reverse. Some correlation with solubility and equilibrium constants for magnesium-amino acid complexes is indicated.</p>