AN ALTERNATIVE SIGNAL-CONSERVATIVE APPROACH FOR RAYLEIGH AND RAMAN SCATTER CORRECTION IN FLUORESCENCE LANDSCAPES

CHIAPPINI F; AZCARATE S; ALCARAZ M R; GOICOECHEA H C

Halifax

Congreso; Chemometrics in Analytical Chemistry; 2018

Fluorescence excitation-emission matrices (EEM) coupled to multi-way analysis have proved to be a powerful tool for the analysis of fluorophoric mixtures or complex systems with analytical purposes [1]. However, scattering phenomena, which are usually present in fluorescence landscapes, can significantly affect the performance of chemometric models. Thus, they must be removed or corrected. In this regard, several methodologies have been proposed. In this work a comparative analysis of different approaches for scattering removal is presented. The particular aspects and fundamentals for each method were analysed. As a result of this study, an alternative methodology is proposed. For the analysis, the effect of the width and height of the scatter signals was also studied. Two experimental systems were chosen considering the stoke shifts between spectra, i.e., a system of fluoroquinolones mixture with large stoke shift in the UV spectral range and system of dyes mixture with very short stoke shift in the Vis spectral range.EEM were processed using the different methodologies and algorithms, e.g. cleanscan [2], eemscat [3] and gauss-fit-based [4], which demonstrated to be efficient for scattering correction. However, interesting aspects were identified, allowing a characterisation regarding robustness, versatility and complexity. In addition, a spectral analysis revealed that interpolations could considerably modify the attributes of the target signals, especially when noise or highly overlapping between scattering and signal are present. Thus, the new methodology presented, lying on the philosophy of the Gaussian fit-based correction, showed to be able to tackle the drawbacks that cannot be overcome for interpolation-based approaches.