(602a) Fluorescence Based Detection of Polychlorinated Biphenyls in Water

Irfan Ahmad, J. Zach Hilt and Thomas D. Dziubla

177 F. Paul Anderson Tower, Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506-0046

irfan.ahmad@uky.edu , thomas.dziubla@uky.edu

Even at very low ppb concentrations, the exposure to the halogenated persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), has been linked to numerous inflammatory diseases, including diabetes, cancer and lowered immune response. As a result, ready detection and sensing of PCBs in water is a critical need, yet is also highly challenging because of its low concentration and highly hydrophobic structure. While the gold standard remains gas chromatography–mass spectrometry (GC-MS), it requires complex sample preparation, is highly time consuming, and requires careful use of internal standards that increases its overall cost. As such, there is still need to develop a robust sensing technique to overcome these challenges. In this work, we evaluate a method for the sensing of organic pollutants using a hydrophobic fluorescent probe, benzopyrene (BP). As many organic pollutants, including PCBs are hydrophobic, BP fluorescence can be increased with trace concentrations of organic pollutants in water. BP forms hydrophobic complexes with organic pollutants that led to successful detection of pollutants including PCB-126, PCB-153, biphenyl and humic acid in water. Furthermore, this fluorophore can be absorbed onto the polymer microparticles (MPs) for advantages such as ease of use, regeneration of the detection system and reducing the overall cost of the method. These fluorophore-MPs attract organic pollutants in water to form hydrophobic complexes on the MPs and results in increase in fluorescent intensity. Polymer is bulk polymerized into a film using free radical polymerization method and then the film is cryogrind into microparticles. Moreover, the absorption and release of fluorescent molecule to and from the MPs has been studied using fluorescent kinetics technique to show the fast absorption and its stability in the water system. Particles were characterized using electron microscopy and their size was measured using light scattering technique. It was demonstrated that the developed material is effectively sensing PCBs in water.