Dissolved organic matter (DOM) is a mixture of predominantly natural macromolecular, organic acids in water. These organic acids play an important role in the transport of micropollutants emitted into the aquatic environment. DOM can influence the solubility, mobility, bioavailability, and toxicity of micropollutants in aquatic systems. Pharmaceutical chemicals, considered emerging micropollutants, are efficiently transmitted through wastewater treatment plants, thereby leading to their widespread presence, and subsequent detection, in rivers and streams. The presence of pharmaceuticals in the aquatic environment can be largely attributed to their inherent physiochemical properties and interactions involving aquatic colloids and perfluorinated compounds (PFCs). PFCs have been present in the environment for many decades but have been recently shown to have serious environmental and health effects. The equilibrium binding constant between pharmaceuticals (sorbent) and PFCs (sorbate) can be measured and quantified by measuring the fluorescence and fluorescence quenching of the sorbate. Determining the sorption constant (Kd) of a model contaminant was performed without the need to separate sorbate from sorbent via static fluorescence quenching of the pharmaceutical chromophore. Perfluorooctanesulfonic acid(PFOS) and perfluorodecanoic acid (PFDA)were used as model sorbates at concentrations of 0-50 mM with ciprofloxacin (CPF) at 3.125 e -4 M. It was hypothesized that the Kdwill vary depending on the source of the fluorescence quenching of CPF in the presence of PFCs. This was evaluated by using an emission scan approach in conjunction with the Stern-Volmer model to derive sorption constants. Non-linear regression was used to fit the quenching models to experimental data. Future anthropogenic compounds found in aquatic environments will be used in order to further analyze Kd.

Sorption of ciprofloxacin to perfluorinated compounds determined through fluorescence quenching

2019 Spring National Meeting

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