Electrokinetic Separation of Chiral Compounds

Femtomole amounts of racemic mixtures of derivatized amino acids were resolved and analyzed rapidly in about 10 minutes by means of high-voltage zone electrophoresis with laser-fluorescence detection. The electrophoresis was performed in capillary columns containing a chiral support electrolyte. A number of dansyl amino acids were resolved by the diastereomeric interaction between the DL-amino acid and the copper(II) complex of L-histidine present in the support electrolyte. A combination of electro-osmotic and electrophoretic action caused all species, positively charged, neutral, and negatively charged, to pass through the 0.5- nanoliter detection volume where they were subjected to laser excitation.