THE POTENTIAL OF FLUORESCENCE POLARIZATION FOR MEASURING SORPTION ISOTHERMS OF ORGANICS

Abstract

ABSTRACT

Sorption isotherms are required to predict the transport and fate of organic pollutants in soils and sediments. Current methods for measuring isotherms involve batch equilibration of sorbate and sorbent, followed by separation and determination of the concentration of sorbate remaining in solution. This approach is not only tedious and time-consuming, but also may be subject to errors associated with incomplete separation or the analytical step.

Fluorescence polarization measurements can distinguish adsorbed and free fluoro-phors without a separation. This is possible because the fluorescence from adsorbed fluorophors is more polarized than the fluorescence from dissolved fluorophors. By measuring polarization as a function of sorbate:sorbent ratios, the necessary information for determining sorption isotherms can be acquired. The capabilities and limitations of the fluorescence polarization approach are considered.