Patent ID: 7191070

Claim:
A method for calculating a number representing an unknown enantiomeric composition of a chiral compound in an unknown sample, comprising: preparing a series of known samples, each of the known samples comprising a first complex, wherein, the first complex in each of the known samples comprises a ratio of a host compound and the chiral compound having a known enantiomeric composition, wherein, in each of the known samples, the ratio of the chiral compound to the host compound remains the same and the enantiomeric composition of the chiral compound is varied, and wherein, in each of the known samples, the concentrations of the chiral compound and of the host compound are at a preset level; collecting and storing spectral data of the known samples at various wavelengths; performing a principal component analysis to select a spectral range of wavelengths in which the spectral differences arising in each of the known samples due to an influence of the enantiomeric composition is most appreciable to give the selected range of wavelengths; performing a partial-least-squares regression of the spectral data over the selected range of wavelengths for each of the series of the known samples to determine a series of regression coefficients and a regression constant; entering the series of regression coefficients for the selected range of wavelengths into a regression vector; collecting and storing spectral data of the unknown sample at the selected range of wavelengths to give unknown spectral data, wherein the unknown sample comprises a second complex having the same ratio of the chiral compound to the host compound as that of the first complex in each of the known samples, and wherein, in the unknown sample, the concentrations of the chiral compound and of the host compound are at the preset level; and inserting the unknown spectral data into the regression vector to allow calculation of the number representing the unknown enantiomeric composition of the chiral compound in the unknown sample, wherein the number is useful for assessing enantiomeric purity of the unknown sample to evaluate its safety and efficacy in pharmaceutical applications.