Interaction between natural organic matter (NOM) and polycyclic aromatic compounds (PAC) - comparison of fluorescence quenching and solid phase microextraction (SPME)

The interaction of phenanthrene and 9-aminophenanthrene with natural organi c matter (NOM) of different origin was investigated using the fluorescence quenching approach and the solid phase micro extraction method. The results of both methods are compared in terms of the influence of the concentratio n of the polycyclic aromatic compounds (PAC) as well as the concentration o f the NOM on the observed binding constant. Due to the combination of stead y-state and time-resolved fluorescence techniques it could be concluded tha t the observed fluorescence quenching was caused by a static interaction li ke a complex formation. While for phenanthrene both analytical methods show ed no long term effects and the reaction equilibrium between NOM and phenan threne was established within the first hour, for 9-aminophenanthrene a slo w reaction kinetics (within days) was found indicating specific interaction s between NOM and the amino group.