DETERMINATION OF ENANTIOMERIC PURITIES USING CD CD DETECTION/

Enantiomeric purities are determined for binary mixtures of D-pseudoep hedrine with the L-enantiomer and with the (+)- and (-)-ephedrines in bulk solutions using circular dichroism (CD) detection in the visible range. The molecules are individually derivatized by ligand exchange w ith tartrate in the first coordination sphere of Cu(II) metal complexe s. Chiral-chiral interactions, after substitution, are specific enough to uniquely discriminate among all four enantiomers using spectra for the mixed complexes. A univariate calibration model is used to predic t enantiomeric purities for mixtures of the pseudoephedrines, and mult ivariate models are used for all three binary mixtures. Results for en antiomeric ratios that lie in the mole fraction range 0.95-1.00 are an improvement over current methods. Achiral mesotartrate is the optimum host ligand to use for the analysis of binary mixtures of diastereois omers.