The influence of sources and solid phase extraction criteria on dissolved organic matter optical properties in aquatic systems

The integrity of studies investigating the composition dissolved organic matter (DOM) is heavily dependent on sampling and instrumental techniques employed. In this study, we aimed to assess impacts both source DOM solid phase extraction (SPE) criteria changes optical properties DOM. Samples were collected from various aquatic environments, ranging headwaters open ocean. kinetics monitored throughout SPE process, with alterations verified using derived chromophoric (CDOM), including absorbance fluorescence measurements. excitation-emission matrices (EEMs) further analyzed PARAllel FACtor analysis (PARAFAC) resolve underlying chemical components. Results indicate that reaction acidification required for polystyrene-divinylbenzene polymer sorbent varies across samples. And variability may stem differences in functional groups sources. maximum carbon loading observed was 9.7 mg C per 1 g PPL, which a widely used styrene-divinylbenzene sorbent, no overloading noted. (DOC) efficiency ( EE ) ranged 51.5-61.5% 27.6-40.0% post- extract- calculations, respectively, significant DOC among different initial concentrations, salinities, flowrates. diverse sources proxies resulting PPL mainly due heterogeneity altered overall molecular characteristics more labile refractory or degraded ocean headwater Notably, high low flowrates yielded identical SPE-DOM alterations. results primarily control rather than methodological other environmental factors. convergence variability. These findings provide crucial insights into inter-study comparisons interpretability SPE-derived data samples environments.