Overcoming Difficulties of Raman Spectroscopy

Raman spectroscopy combines the information density of vibrational spectroscopy with the experimental flexibility of optical spectroscopy. It provides label-free analysis of samples in solid, liquid, crystalline and gas phases.

Although a ‘weak’ effect, Raman spectroscopy can be applied in fast reactions using standard sampling arrangements. When the millisecond timescale is desired or samples give weak scattering, then every photon counts and it may be tempting to use higher laser power. Locally intense laser powers generate heat and thermal damage, photodegradation and bleaching as well as background fluorescence. Less obviously, given that typically CW lasers are used, two-photon processes can also present challenges.

The wide range of situations that can be encountered present many unique challenges particular to each application, but there are a number of principles that are common to all. The design of the system as a whole is key to success in overcoming apparent limitations to Raman spectroscopy.

This webinar, presented by Prof. Wesley Browne, University of Groningen, will also show how these same artefacts can provide information beyond the vibration and be used to increase the information density of this remarkable technique.

Key learning objectives:

• Samples that are fluorescent or photo- and thermally sensitive
• Choice of wavelength (UV to NIR) in terms of photon flux and thermal management
• Inhomogeneities and surface behaviour
• Dynamicity/speed in single and multi-phase flows – rapidity of species transformation either as the reaction progresses or when influenced by external parameters
• Stopped flow reaction monitoring – why use Raman rather than the more conventional absorption approach

Who should attend
Those working to analyse weakly scattering or complex and sensitive samples for inline reaction progress monitoring.