Enantiomeric separation of free L-and D- amino acids in hydrolyzed protein fertilizers by CE-MS2

Hydrolyzed protein fertilizers (HPFs) are obtained mainly by chemical hydrolysis, or through enzymatic hydrolysis, and they typically contain free amino acids, oligo- and poly-peptides.During the chemical hydrolysis, strong agents (acids or alkali) and high temperatures are used which should produce the L-amino acids racemization to their mirror image configuration leading to a loss in their biological activity.In the search for processes that do not induce racemization, enzymatic hydrolysis has become an alternative which preserves the original enantiomeric form from the original raw material. Two methods by CE-ESI-MS2 are proposed using cyclodextrins as chiral selectors in order to determine the degree of racemization of the free amino acids contained in different HPFs used as plant biostimulants.