.a simple spectrofluorimetric method is described for the determination of doxorubicin (dxr) based on its quenching effect on the fluorescence intensity of tb 3+ - deferasirox (dfx) complex as a fluorescent probe. the excitation and emission wavelengths were 328 and 545 nm, respectively. the effects of ph, time, order of addition of reagents, concentrations of tb 3+ and dfx and the buffer volum...