Characterisation of dissolved organic matter in karst spring waters using intrinsic fluorescence: Relationship with infiltration processes

► From analysis of spectrophotometric properties of dissolved organic matter (OM) and the hydrochemical responses of some karst springs. ► Characterization of the origin and transfer pathway of the organic matter present in the water, from soil and epikarst toward the spring. ► Most of the organic compounds present in the water from these springs are associated with the fulvic-like substances. ► A small proportion of organic matter is originated in situ as a result of microbiological activity. ► Existence of a relation between intrinsic fluorescence and some hydrochemical variables (TOC and NO3−), related to rapid water flows from the soil toward the aquifer.