[Spectrofluorometric trace determination of cerium(III) with ethylenediamintetraksi (methylphosphonic acid)]

Fluorescence of Ce(III) was greatly enhanced when Ce(III) forming 1:1 complex with ethylenediaminetetrakis (methylphosphonic acid)(EDTP) in solution of pH 7-8. The use of EDTP in the spectrofluorometric determination of trace amounts of cerium(III) ions is described. The apparent excitation and fluorescence wavelength are 313 and 397 nm, respectively. The fluorescence varies linearly with the concentration of cerium(III) in the range of 1 x 10(-8)-1 x 10(-4) mol.L-1, which is closed to the known best method. The quenching effects of some inorganic ions and other lanthanides are also investigated, which indicated that the method is superior to others in climinating the interfere of other ions, especially for Pr3+ and PO4(3-) ions.