Abstract: A new strategy for the quantitative determination of enantiomeric purity that combines guest-host complexation, spectroscopy, and chemometric modeling. 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. In this strategy, the concentration of the chiral compound does not have to be fixed or known.

Abstract: A method for classifying textile samples and unknown fabrics into known categories using spectroscopy, chemometric modeling, and soft independent modeling of class analogies (“SIMCA”). The method involves collecting spectral data, preferably diffuse near infrared reflectance data, for a library of known fabric samples, creating a database of principal component analyses for each type of fabric, and using SIMCA to classify an unknown fabric sample according to the database.

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 strategy, or method, for the quantitative determination of enantiomeric purity that combines lin situ enantiomer diastereomerization', spectroscopy, and chemometric modeling. Spectral data for samples of known enantiomeric composition is subjected to a type of multivariate regression modeling known as partial least squares (“PLS-I”) regression. The PLS-I regression produces a mathematical model that can be used to predict the enantiomeric composition of a set of samples of unknown enantiomeric purity. In this strategy, the guest-host complexation utilizes improved chiral selector molecules, including chiral amines and chiral alcohols such as phenylethylamine and 1,2-propanediol, that form ion pairs or covalent bonds with the chiral analytes.

Abstract: A new strategy for the quantitative determination of enantiomeric purity that combines guest-host complexation, spectroscopy, and chemometric modeling. 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. In this strategy, the concentration of the chiral compound does not have to be fixed or known.

Abstract: A method for classifying textile samples and unknown fabrics into known categories using spectroscopy, chemometric modeling, and soft independent modeling of class analogies (“SIMCA”). The method involves collecting spectral data, preferably diffuse near infrared reflectance data, for a library of known fabric samples, creating a database of principal component analyses for each type of fabric, and using SIMCA to classify an unknown fabric sample according to the database.

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 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: 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: A new strategy for the quantitative determination of enantiomeric purity that combines guest-host complexation, spectroscopy, and chemometric modeling. 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: 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 method and apparatus for quantitatively determining chlorine content and fractional abundance of chlorine isotopes in unknown samples. When using this method and apparatus to determine chlorine content, isotope dilution principles may be employed. Chlorine isotopes used for diluting an unknown sample may be .sup.35 Cl or .sup.37 Cl, and relative isotope content in the diluted mixture may be measured using infrared spectrometry.

Abstract: Apparatus and method for qualitatively and quantitatively analyzing infrared emission from excited molecules in the determination of, for example, total inorganic carbon, chloride and available chlorine in aqueous samples. Methods of exciting the gas-phase, infrared-active molecules to emit radiation include flame excitation, furnace excitation, excitation by electron impact in a gas discharge or excitation by collisions with a vibrationally excited diatomic molecule. The detector is optimized by use of dual beam system with background subtraction capabilities thereby eliminating background noise and fluctuations therein.

Abstract: Apparatus and method for qualitatively and quantitatively analyzing infrared emission from excited molecules in samples of interest is disclosed. Over the wavelength interval from 1 to 5 um, two strong emission bands are observed with a PbSe detector when organic compounds are introduced into an hydrogen/air flame. The band at 4.3 um (2326 cm.sup.-1 is due to the asymmetric stretch of carbon dioxide while the band at 2.7 um is due to both water and carbon dioxide emission. The carbon dioxide emission at 4.3 um is most intense at the tip of the flame, and increases with the amount of organic compound introduced into the flame. For chromatographic application, an optical filter can be used to isolate the 4.3 um emission band. The infrared emission detection system finds application in the determination of total inorganic carbon, chloride and available chlorine in aqueous samples.

Abstract: A dispersive optical spectrometer is disclosed which comprises light detection means, dispersion means for separating light radiation into spectral components and for directing the spectral components toward the light detection means, means for admitting light radiation into the entrance focal plane and for directing the light radiation toward the dispersion means, the light radiation admitting means including a plurality of spaced-apart apertures, and light transmission means for transmitting light radiation from a light source to one or more of the apertures. In a preferred embodiment, the apertures form a two-dimensional, rectilinear array for producing non-overlapping spectra.

Abstract: A dispersive optical spectrometer is disclosed which comprises light detection means, dispersion means for separating light radiation into spectral components and for directing the spectral components toward the light detection means, means for admitting light radiation into the entrance focal plane and for directing the light radiation toward the dispersion means, the light radiation admitting means including a plurality of spaced-apart apertures, and light transmission means for transmitting light radiation from a light source to one or more of the apertures.