CHIRAL INTERACTION AND STOCHASTIC KINETICS IN STIRRED CRYSTALLIZATIONOF AMINO-ACIDS

A study of chirally selective interaction in the stirred crystallizati on of glutamic acid and lysine is presented. The crystallization of S- glutamic acid is influenced by the presence of S-lysine but not R-lysi ne. Crystal nuclei in stirred systems are produced due to secondary nu cleation. Secondary nucleation is an autocatalytic process in which a crystal produces secondary nuclei due to fluid motion, and due to crys tal stirrer and crystal-crystal collisions. As a result of this autoca talysis, small fluctuations in the nucleation rates are amplified and the kinetics show a marked stochastic behavior. We investigate the sto chastic behavior in detail and propose a kinetic mechanism that explai ns both the increase and the statistical distribution of the crystalli zation times of S-glutamic acid due to the presence of S-Lysine. (C) 1 998 Wiley-Liss, Inc.