Utilization of UV-Vis spectroscopy and related data analyses for dissolved organic matter (DOM) studies: A review

Despite the popular use of UV-Vis spectroscopy for dissolved organic matter (DOM) studies, many of the derived parameters and the related methods have been rather limitedly used for certain areas of DOM studies, which warrants the extension of their applications into a wider range of research topics as well as critical comparison of individual parameters. In this review, we comprehensively compared the UV-Vis spectroscopy-based DOM parameters widely used for the last few decades, aiming to broaden our knowledge about the utilization of the spectra for DOM studies through bridging the gaps between different research areas (e.g., natural versus engineered systems). The parameters for chromophoric DOM (CDOM) addressed here encompass absorption coefficient, absorption ratios, spectral slopes, derivative and differential spectra, Gaussian decomposition, and two-dimensional correlation analysis. The benefit of using such parameters could be maximized in complementary uses both for static environments and dynamic processes. For the fullest utilization of the spectral potential, it is recommended to open the raw UV-Vis spectra and the measurement conditions (solution chemistry, types of water, wavelengths, derivation methods, etc) to the public, which can enhance global comparison and our understanding of the fate and the distribution of CDOM and the dynamics in various aquatic environments.