Sh. Wang et al., DIRECT MEASUREMENT OF ENANTIOMERIC EXCESS OF SYNTHETIC TERT-LEUCINE WITH A CHIRAL-LIGAND-EXCHANGE CHROMATOGRAPHY, Journal of the Chinese Chemical Society, 42(6), 1995, pp. 953-956
Racemic tert-leucine can be completely resolved by ligand exchange chr
omatography (LEG) using a Chiralpak WH column. The retention time of t
he tert-leucine was decreased by increasing concentration of Cu2+, or
decreasing pH of the eluent whereas it was unaffected by varying the t
emperature of eluent. Optimal conditions for complete separation of th
e D,L-tert-leucine were found to be (Cu2+, 5.0 mM, PH 5.5, 25 degrees
C). The enantiomeric excess of synthetic tert-leucine, a chiral auxili
ary reagent, was determined.