A new fluorescence index with a fluorescence excitation-emission matrix for dissolved organic matter (DOM) characterization

AbstractA series of fluorescence approaches have been employed to characterize the composition, transformation, and biogeochemical cycles of aquatic dissolved organic matter (DOM). However, there is no consensus on the protocols for elucidating DOM fluorescence spectra from protein-like (young DOM) to humic-like (old DOM) types, which are associated with the intrinsic fluorescence properties involved in the excitation/emission and detection of DOM. The central objective of this study was to evaluate the excitation–emissions matrices (EEMs)-average area of fluorescence intensity response using DOM fluorescence spectra collected on six different DOM surrogates using high-performance size-exclusion chromatography techniques. We evaluated criteria and protocols of a new Y fluorescence index (YFI) for comparison with McKnight fluorescence index (MFI), in which 280 nm excitation coincides with independent inferences with response to emission wavelengths from 350 to 450 nm. Our results demonstrate that YFI had s...