Fluorimetry determination of trace Ce3+ with EDTP.

The use of ethylenediaminetetrakis(methylphosphonic) acid (EDTP) in the fluorimetry determination of trace amounts of Ce3+ ions is described. The fluorescence intensity of Ce3+ was greatly enhanced when an 1:1 complex with EDTP in solution of pH 7-8 formed. The apparent excitation and emission wavelength used were 313 and 397 nm, respectively. The fluorescence intensity varied linearly with the concentration of Ce3+ in the range of 1 x 10(-8) -1 x 10(-4) mol l(-1). The quenching effects of coexist ions (other rare earth ions, Fe3+ and some inorganic anions) were studied. This technique has unique advantage in eliminating disturb of coexist.