Using Rayleigh Scattering to Correct the Inner Filter Effect of the Fluorescence Excitation-Emission Matrix

Excitation-emission matrix (EEM) spectroscopyhas been provento be an effective tool for offline fluorescence analysis. However,the pretreatment of EEM data requires an additional ultraviolet-visible(UV-vis) absorption spectrum for inner filter effect (IFE)correction. This complicates the instrument structure and increasesthe test flow, thus hindering the practical application of EEM inenvironmental online monitoring. In this work, Rayleigh scatteringin EEM, which is often masked, is leveraged to address this challengeas Rayleigh scattering light itself passes through the sample andexperiences absorption. We establish a translation-corrected estimationby the Rayleigh scattering (TCERS) method to estimate absorbance,not only enabling the IFE self-correction of EEM but also providingorthogonal spectroscopy information. TCERS is hierarchically testedin real solutions, simulated turbid liquids, and various natural watersamples. Results indicate that the predicted UV-vis absorptionspectra have a cosine similarity of over 0.95 with the actual spectra.When using the predicted spectra to correct the IFE of EEM, only about0.005/1.440 bits of information entropy are lost and the absoluteerrors in EEM are negligible. The proposed method has the potentialto streamline the design of fluorescence spectrometers, making itpossible to miniaturize, optimize, and popularize these instrumentsfor various practical applications such as environmental monitoring.