Patent ID: 8189188
Filing Date: 2012-05-29
Classification: G01N

Abstract:
1. A method for determining an unknown enantiomeric composition of a chiral compound in an unknown sample without using concentration of the chiral compound as a variable, comprising: preparing a plurality of 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 in any one series, the ratio of the chiral compound to the host compound remains the same and the enantiomeric composition of the chiral compound is varied, wherein, in each of the known samples in any one series, the concentrations of the chiral compound and of the host compound are at a preset level, and wherein each of the plurality of series of known samples has a different concentration of the chiral compound; collecting 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 and the regression constant into a regression vector; collecting 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 concentration of the host compound as that of the known samples, and wherein, in the unknown sample, the concentration of the chiral compound is unknown; and inserting the unknown spectral data into the regression vector to allow calculation of the unknown enantiomeric composition of the chiral compound in the unknown sample.