Reading: Chapters 16 – 18
Homework: Due 4/10/2014
IR and Raman
16: 1, 7, 10, 15
17: 1, 3, 6,
18: 2, 3, 6
Both Raman and FT-IR generally provide similar molecular identification results, so they tend to be competitive. A key advantage of Raman spectrometry is that it requires little or no sample preparation. In fact, samples can even be analyzed without removing them from their packaging materials, such as a glass bottle or plastic bag, making the technique particularly useful in various forensic and pharmaceutical applications.
Raman instruments have historically been much more expensive than FT-IR instruments because they require high-stability laser sources. Over the past 10 years, however, technology advancements have improved the sensitivity of Raman detectors while costs have dropped substantially.
In many applications, the extra cost of Raman spectroscopy can easily be justified in productivity savings. The analysis can usually be performed with a probe connected to a long fiber cable that leads back to the instrument, which may be located in a different part of the facility.
How is it possible to take a Raman spectra through a plastic bag? What type of improved detector technology is making Raman cost effective?