Direct Laser-Induced Breakdown Spectroscopy Analysis of Estuarine Suspended Particulate Matter Collected on Filters

Estuaries are dynamic environments that influence the transport of metals and nutrients from land to sea, with suspended particulate matter (SPM) serving as a key vehicle for them. Laser-Induced Breakdown Spectroscopy (LIBS) offers a rapid, versatile, and non-destructive approach for multi-element analysis of SPM, allowing their direct measurement on collected filters without complex sample preparation. In this study, LIBS was applied to evaluate the spatio-temporal variability of major and trace elements (Si, Fe, Al, Ti, Na, Li, K, Rb, Ca, and Mg) along the Pacoti River estuary, Brazil, during rainy and dry seasons. Elemental patterns generally reflected the salinity gradient and tidal dynamics, highlighting element-specific behaviors with most elements showing inverse correlations with salinity, while Ca and Mg displayed positive correlations. These findings confirm the potential of LIBS as a powerful tool for environmental monitoring, providing rapid, high-throughput characterization of SPM and enabling an improved understanding of biogeochemical processes in estuarine systems.