02863naa a2200277 a 450000100080000000500110000800800410001902200140006002400570007410000210013124502060015226000090035830000110036752019460037865300290232465300290235365300200238270000180240270000170242070000150243770000250245270000200247770000160249770000240251377300480253721343082022-06-10       2021    bl uuuu     u00u1 u    #d  a0883-29277 ahttps://doi.org/10.1016/j.apgeochem.2021.1050492DOI1 aMORAIS, C. P. de  aAssessing extracted organic matter quality from river sediments by elemental and molecular characterizationbApplication to the Tietê and Piracicaba Rivers (São Paulo, Brazil).h[electronic resource]  c2021  a1 - 11  aUrban river pollution causes serious problems to the environment, human health, and water scarcity. Developing tools to identify and assess the health of aquatic river systems is essential for monitoring the quality of rivers and implementing actions. This study assesses the elemental and molecular characteristics of organic matter (OM) extracted from river sediments and associates them with river quality. To assess the quality of sediment cores, the most reactive and available OM from two urban rivers (Tietˆe and Piracicaba Rivers, S˜ ao Paulo, Brazil) was isolated with alkaline and water solutions. It was then characterized by elemental composition, ultraviolet–visible spectroscopy, and fluorescence excitation-emission matrix with parallel factor analysis. The average yield of alkaline extraction was 40.71% ± 5.52% of OM present in the bulk sediments. Extracted organic matter from sediments (EOMSed) from the Tietˆe River presented the highest average concentrations of nonpurgeable organic carbon (NPOC) and total organic nitrogen (TON), and the lowest average NPOC/TON molar ratios and specific UV absorbance at 254 nm (SUVA254). Considering the high degree of eutrophication in the Tietˆe River, these results suggest a greater input of simple OM with nitrogenous structures. The humic-like component in EOMSed was the most abundant in both rivers. The aromaticity of EOMSed from the Piracicaba River was evidenced by the greater contribution of complex structures in the form of aromatic and polyaromatic moieties and higher SUVA254. EOMSed from the Tietˆe River also featured enhanced biological activity due to the greater contribution of microbial-derived products and the presence of small molecules and nitrogenous structures. As this combination of elemental and spectroscopic techniques successfully identified the characteristics of extracted OM, it can be used as a tool to assess the global river quality  aExtracted organic matter  aParallel factor analysis  aRiver sediments1 aTADINI, A. M.1 aBENTO, L. R.1 aOURSEL, B.1 aGUIMARÃES, F. E. G.1 aMARTIN NETO, L.1 aMOUNIER, S.1 aMILORI, D. M. B. P.  tApplied Geochemistrygv. 131, 105049, 2021.