Stereoselective Analysis of Tartaric Acid Using Complexation with Eu3+-Tetracycline and Capillary Electrophoresis - Abstract
Tartaric acid was incubated with Eu3+-tetracycline and the sample was analyzed by capillary electrophoresis utilizing post-column laser-induced luminescence detection. The D-isomer was detected at concentrations as low as 5 µM. The L-isomer was not detected. The juice from fresh loquat fruit was found to contain 41 mM D-tartaric acid. Further study was undertaken to determine the basis for the stereoselectivity. Molecular modelling was not consistent with the D-isomer forming a more stable complex. The rates of dissociation of the Eu3+-tetracycline-tartarate complexes during the separation were determined. Rates were consistent with the complex with the L-isomer degrading during the separation.