Sorption-luminescence method for determination of europium using acid-modified clinoptilolite

Sorption-luminescent method for europium determination based on the acid-modified Transcarpathian clinoptilolite without using toxic organic solvents was proposed. Optimal luminophore preparation condition is the sorption of Eu(III) on the precalcined at 400 degrees C H-clinoptilolite, in the solution with pH 9.5. The obtained H-clinoptilolite-Eu(III) sample, precalcined at 50 degrees C, was treated with 1,10-phenanthroline, atophan, and urotropine solutions. For luminescence excitation, the rays with wavelength of lambda=276nm were used. Luminescence intensity at lambda=615nm was selected as an analytical parameter for a europium quantitative determination. Linear calibration range of Eu(III) concentration with the detection limit of 3ngmL(-1) is within 10-900ngmL(-1). The proposed method can be used for europium determination in the presence of many rare earths. Sorption-luminescent method can be applied for the determination of europium ions trace amounts in synthetic water solutions. The proposed analytical method gave recoveries from 95 to 102% and RSD from 3.5 to 7.9% during the determination of europium.