Seeing the Full Picture

The analytical world in general has yet to appreciate the power of FTIR spectroscopic imaging for process analysis. Here’s why it should be in your toolkit.

By Sergei Kazarian, Professor of Physical Chemistry, Department of Chemical Engineering, Imperial College London, UK.

Fourier transform infrared (FTIR) spectroscopic imaging emerged two decades ago as a promising method for analyzing a range of different materials (1). Since then, it has been perceived mainly as a technique for obtaining chemical images of heterogeneous materials and samples, such as polymer blends or biological tissues. A chemical snapshot generated using FTIR imaging by recording many of IR spectra simultaneously is somewhat similar to a photograph from a conventional camera, the main difference being that it reveals features invisible to human eye – the images are based on chemical rather than visual differences. Thus, a chemical image is truly worth a thousand spectra!

However, spectroscopic imaging has even greater potential for chemical imaging of processes and systems that change with time. Surprisingly, this very exciting capability of spectroscopic imaging is underused. Modern FTIR spectroscopic imaging (using fast array detectors) offers itself as an experimental tool for studying dynamic systems. Indeed, a modern analytical chemist will often need to apply techniques in situ, online or inline and ultimately for industrially relevant processes. FTIR spectroscopic imaging usually can be applied in conjunction with different accessories – a microscope being one of the most familiar.