Determination of Indomethacin Crystallinity in the Presence of Excipients Using Diffuse Reflectance Near-Infrared Spectroscopy

2001 ◽  
Vol 6 (4) ◽  
pp. 573-582 ◽  
Author(s):  
Jeffery J. Seyer ◽  
Paul E. Luner
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Diffuse Reflectance ◽  
Near Infrared

Near- versus Mid-Infrared Diffuse Reflectance Spectroscopy for the Quantitative Determination of the Composition of Forages and By-Products

1994 ◽  
Vol 2 (1) ◽  
pp. 49-57 ◽  
Author(s):  
James B. Reeves
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Reflectance Spectroscopy ◽  
In Vitro Digestibility ◽  
Mid Infrared ◽  
Infrared Spectrometer ◽  
By Products

The objective of this work was to explore the relative value of near- and mid-infrared diffused reflectance spectroscopy in determining the composition of forages and by-products. Sixty-seven samples consisting of 15 alfalfa, 16 tall fescue and 15 orchard grass hays, 10 corn stovers and 11 wheat straws at various stages of maturity were examined by diffuse reflectance using a scanning monochromator (1100–2500 nm), a Fourier near infrared spectrometer (10,000–4000 cm−1, 4 and 16 cm−1 resolution, neat and 5% sample in KBr) and a Fourier mid-infrared spectrometer (4000–400 cm−1, 4 and 16 cm−1 resolution, neat and 5% sample in KBr). Samples were analysed chemically and spectroscopically for fibres, in vitro digestibility, crude protein, nitrobenzene oxidation products and various measures of lignin content. The results showed that diffuse mid-infrared reflectance spectroscopy can perform as well as, and sometimes better than, diffuse near infrared spectroscopy in determining the composition of forages and by-products. In addition, Fourier near infrared spectroscopy did not perform as well as either near infrared using a scanning monochromator or the Fourier mid-infrared spectrometer. Finally, diluting samples with KBr was not beneficial for either Fourier based determinations. Additional work with more diverse data sets and various Fourier instrument configurations will be needed to further define the limits and usefulness of Fourier transform near- and mid-infrared spectroscopy in the determination of forage and by-product composition.

Comparison of Diffuse Reflectance Fourier Transform Mid-Infrared and Near-Infrared Spectroscopy with Grating-Based Near-Infrared for the Determination of Fatty Acids in Forages

2007 ◽  
Vol 55 (21) ◽  
pp. 8302-8309 ◽  
Author(s):  
Francisco J. Calderon ◽  
James B. Reeves, III ◽  
Joyce G. Foster ◽  
William M. Clapham ◽  
James M. Fedders ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Mid Infrared

Nondestructive Direct Determination of Heroin in Seized Illicit Street Drugs by Diffuse Reflectance near-Infrared Spectroscopy

2008 ◽  
Vol 80 (19) ◽  
pp. 7257-7265 ◽  
Author(s):  
Javier Moros ◽  
Nieves Galipienso ◽  
Rocío Vilches ◽  
Salvador Garrigues ◽  
Miguel de la Guardia
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Direct Determination ◽  
Street Drugs

Determination of Ephedrine Hydrochloride in Mixtures of Ephedrine Hydrochloride and Pseudoephedrine Hydrochloride Using near Infrared Spectroscopy

2005 ◽  
Vol 13 (3) ◽  
pp. 155-160 ◽  
Author(s):  
Yanga K. Dijiba ◽  
Thomas M. Niemczyk
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Near Infrared Spectroscopy ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Minor Component ◽  
Ephedrine Hydrochloride ◽  
Calibration Samples ◽  
Precision And Accuracy

There are a number of situations where there is a need to determine the concentrations of components in solid-state mixtures without dissolving the samples. The experiments described here were designed to demonstrate that diffuse reflectance near infrared spectroscopy coupled with partial least squares (PLS) data analysis can be used to determine the minor component in a mixture of structurally-similar solid-state compounds, in this case mixtures of ephedrine hydrochloride and pseudoephedrine hydrochloride. It is shown that when care is taken to produce homogeneous calibration samples very good results can be obtained; in this case, cross-validated standard error of predictions of 2.30 wt% when the minor component spanned the concentration range of 0 to 50 wt% and 0.30 wt% when the minor component spanned the concentration range of 0 to 5 wt%. Results are presented that indicate that the amount of data available to the PLS calibration routine relative to the range over which the calibration is performed can limit the precision and accuracy of the determinations.

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