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Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence



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Anal Chem . 2020 Dec 15;92(24):15745-15756.

doi: 10.1021/acs.analchem.0c02696. Epub 2020 Nov 21.


The variable configuration of Raman spectroscopic platforms is one ofthe major obstacles in establishing Raman spectroscopy as a valuable physicochemicalmethod within real-world scenarios such as clinical diagnostics. For such real worldapplications like diagnostic classification, the models should ideally be usable to predictdata from different setups. Whether it is done by training a rugged model with data frommany setups or by a primary-replica strategy where models are developed on a‘primary’setup and the test data are generated on‘replicate’setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable.However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if thesame samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumentalconfiguration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correctfor them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST(European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allowsvarious instrumental configurations ranging from highly confocal setups tofibre-optic based systems with different excitationwavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts,intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improvethe inter-laboratory studies