Cellulose diacetate films as a solid-phase matrix for fluorescence analysis of pyrene traces in aqueous media

We report on the possibility of using cellulose diacetate (CDA) films as a solid-phase matrix for the fluorescence analysis of pyrene in aqueous micellar media. We examined the effect of the concentration of three surfactants—the anionic sodium dodecyl sulfate (SDS), the cationic cetyltrimethylammonium bromide (CTAB), and the nonionic polyoxyethylene (10) mono-4-isooctylphenyl ether (TX-100)—on the fluorescence of pyrene in aqueous micellar solutions before and after sorptional concentration and as adsorbed on CDA films. The increased fluorescence intensity of pyrene on the solid-phase matrix was due to pyrene solubilization in the surfactant hemimicelles formed on the sorbent surface. The highest degree of pyrene recovery on CDA was achieved in the presence of micelles of the cationic CTAB. The surface electric potential of the CDA films was negative (−31.5 ± 2.5 mV), affecting the hydrocarbon recovery degree. The recovery degree and the polarity index of the pyrene molecules’ microenvironment in solution decreased in the sequence CTAB > SDS > TX-100.