FT-IR Spectroscopy

Oct 01, 2011
Spectroscopy
How can you navigate the maze of choices for detecting molecular vibrations with mid-infrared (IR), near IR (NIR), and visible (Raman)? Understanding what is being measured, how it is measured, and the advantages and disadvantages of each technique, will help.
Oct 01, 2011
Spectroscopy
Continued discussion of the classical least squares approach to calibration, with a focus on the reconstruction of mixtures
Aug 01, 2011
Special Issues
Liquid chromatography–mid infrared spectroscopy (LC-IR) is a powerful tool for copolymer analysis. This article describes an automated, self-regulating solvent-removal interface that produces continuous transmission spectra from the deposited, solvent-free, solid-phase chromatogram.
Aug 01, 2011
Special Issues
In recent years, attenuated total reflection (ATR) spectroscopy has become the preferred method for many routine infrared (IR) measurements. However, the simplicity of the technique has made it available to users who may not be aware of some effects that significantly influence the appearance of ATR spectra. This results in changes to the relative intensities of different absorption bands. The aim of this article is to explain the origin of these effects and to provide examples. In particular, it will focus on those effects that are not evident from inspection of the spectra.
Aug 01, 2011
Special Issues
Process analytical technology (PAT) and hot-melt extrusion (HME), commonplace in the food and polymer industries, are becoming increasingly deployed in the pharmaceutical industry. Herein the application of in-line, transmission mode, Fourier-transform near-infrared (FT-NIR) spectroscopy to the HME manufacturing platform for a drug product in development is detailed. NIR spectroscopy and partial least squares (PLS) models were developed for real-time active pharmaceutical ingredient (API) loading (%wt/wt) and surfactant loading predictions. These predictions were used for fault detection, isolation of suspect material, and real-time troubleshooting during HME. Additionally, the NIR/PLS output was used for real-time release of the intermediate drug product.
Aug 01, 2011
Special Issues
When combined with the rapid scan speeds of modern instruments, Fourier-transform infrared (FT-IR) spectroscopy provides a powerful real-time method for monitoring chemical changes (for example, the optical adhesive caused by illumination of a UV lamp). This article describes the characterization of several adhesives used in an optical assembly. Several different approaches to measuring the rate of change during the curing experiment are described. As the number of uses for UV curing and photopolymerization increases, real-time FT-IR should play a major role in characterizing these new materials and products.
Jun 01, 2011
Spectroscopy
Algae and other aquatic species are promising sources for biomass that can be economically converted into fuel, and several infrared sampling techniques can be used to analyze these samples.
May 01, 2011
Spectroscopy
In the last four columns we described the theory of what should happen when we perform classical least squares calculations on mixtures when Beer's law applies. In this column we take our first look at what actually does happen.
Feb 11, 2011
Application Notebook
By Spectroscopy Editors
FT-IR diffuse reflectance sampling coupled with an environmental temperature chamber offers a convenient method to study sample degradation, to evaluate catalyst efficiency, and to determine reaction pathways as a function of temperature and pressure.
Feb 11, 2011
Application Notebook
Infrared analysis of seized drugs is underutilized in many forensic laboratories owing to the ambiguous results produced by samples containing a mixture of compounds. The use of a patented multi-component search algorithm can help overcome the limitations of infrared for the identification of drugs in mixture samples.
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