The probable directions in which the technique of near infrared Fourier Transform Raman spectroscopy will advance are discussed. The analysis considers the limitations of the method and the instrumental balances which may be found for different applications. Discussion is from an instrumental viewpoint, including filtering, detection, excitation, sampling techniques and data analysis. Applications of these advances in the analytical environment are suggested. Spectra are presented from a system which employs Q-switched Nd:YAG excitation and a gated detector in order to discriminate against long-lived spectral backgrounds. Dramatic reductions in the background from hot samples are demonstrated.
THE RECENT interest in Fourier Transform Raman (FTR) in the NIR has been fuelled by promises of fluorescence-free spectra with simple sampling methods. This is, in fact, not far from the truth as this compilation demonstrates. The cost of instrumentation for such a set-up, relative to "conventional" Raman spectrometers, makes it very attractive. With all the advantages of the technique, including the Jacquinot advantage and, in some cases, the multiplex advantage [2], there are now fewer application areas accessible through the use of ultraviolet visible Raman systems.7
It is therefore the aim of this paper to introduce some of the advances which will improve, both qualitatively and quantitatively, the performance of NIRFTR instruments. In addition, some examples of applications that will become available to the analytical chemist are suggested, as specific areas of instrumentation are enhanced.