Abstract: A method for determining sugar concentration using spectropolarimetry and multivariate regression modeling A set of fixed polarizers are used in association with a spectrometer, which enables the measurement of optical rotation as absorbance values over a range of wavelengths. The adverse effects of color within the samples is corrected by measuring a background level of absorbance that is not due to optical rotation and using this as a baseline. A regression model is then developed for predicting sugar concentration in unknown samples. This method is effective even if the sample is colored.

Abstract: A new method and strategy for the quantitative determination of enantiomeric purity that combines polarimetry, spectroscopy, and chemometric modeling. Spectral data is collected after a light beam is passed through a first polarimeter, a sample of a chiral compound, and a second polarimeter oriented at a 45 degree angle relative to the first polarimeter. The spectral data for samples of known enantiomeric composition is subjected to a type of multivariate regression modeling known as partial least squares (“PLS-1”) regression. The PLS-1 regression produces a mathematical model that can be used to predict the enantiomeric composition of a set of samples of unknown enantiomeric purity.

Abstract: A new method and strategy for the quantitative determination of enantiomeric purity that combines polarimetry, spectroscopy, and chemometric modeling. Spectral data is collected after a light beam is passed through a first polarimeter, a sample of a chiral compound, and a second polarimeter oriented at a 45 degree angle relative to the first polarimeter. The spectral data for samples of known enantiomeric composition is subjected to a type of multivariate regression modeling known as partial least squares (“PLS-1”) regression. The PLS-1 regression produces a mathematical model that can be used to predict the enantiomeric composition of a set of samples of unknown enantiomeric purity.

Abstract: The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.

Abstract: A dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials is shown. The device shows: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.

Abstract: The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.

Abstract: The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.