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Determination of Acetone in a Water/Toluene Emulsion in Each Phase Using Raman Spectroscopy with Scattered Light
Erik Spoor1, Matthias Rädle1, Jens-Uwe Repke2
1CeMOS Research and Transfer Center, Technische Hochschule Mannheim, Paul-Wittsack-Str. 10, 68163 Mannheim, Germany.
Sensors (Basel, Switzerland)
|April 14, 2026
Summary
Raman spectroscopy can now quantify components in emulsions by correcting for light scattering. This method accurately determines acetone concentration in individual liquid phases of water-toluene-acetone mixtures.
Area of Science:
- Analytical Chemistry
- Spectroscopy
- Physical Chemistry
Background:
- Raman spectroscopy is valuable for qualitative and quantitative mixture analysis.
- Light scattering in emulsions limits Raman spectroscopy's effectiveness.
- Previous work demonstrated quantifying signal loss with a scattered light probe.
Purpose of the Study:
- To demonstrate Raman spectroscopy's ability to determine acetone concentration in individual liquid phases of an emulsion.
- To validate a method for correcting light scattering-induced signal losses.
- To analyze a water-toluene-acetone emulsion.
Main Methods:
- Quantifying signal losses using a scattered light probe.
- Creating a ternary diagram by establishing stable conditions and separating phases.
- Measuring samples as dispersed mixtures with droplets as interfering factors.
Main Results:
- Acetone concentration was determined with a root mean squared error of prediction (RMSEP) of up to 1.5 wt% in a water-toluene-acetone emulsion.
- The developed correction method enabled the determination of acetone concentration in each individual liquid phase.
- Identical concentration differences between phases were measured in both separated and dispersed samples.
Conclusions:
- The scattered light probe method effectively corrects for signal losses in emulsions.
- Raman spectroscopy, with scattering correction, can quantitatively analyze components in individual phases of liquid dispersed mixtures.
- This technique enhances the applicability of Raman spectroscopy for complex emulsion analysis.
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