Spectrofluorimetric determination of trace amounts of europium(III) ion with lutetium(III)-sparfloxacin-sodium dodecyl sulfate luminescence enhancement system.

A new luminescence-enhancement system based on complex formation between europium and sparfloxacin in the presence of lutetium in a sodium dodecyl sulfate solution has been discovered. By adding a suitable amount of Lu3+ to the Eu-sparfloxacin-sodium dodecyl sulfate system, the luminescence can be enhanced by approximately 5-fold compared with that of the system without Lu3+. Under the optimum conditions, the luminescence intensity of the system is a linear function of the concentration of europium in the range of 1.0 x 10(-10) - 5.0 x 10(-7) mol L(-1). The detection limit of europium is 2.0 x 10(-13) mol L(-1) (S/N = 3). The system was used for the determination of trace amounts of europium in rare earth samples with satisfactory results.