Spectrofluorimetric determination of europium and samarium with mixtures of 2-thenoyltrifluoroacetone and tri-n-octylphosphine oxide in aqueous solutions containing triton x-100

The europium or samarium complex with thenoyltrifluoroacetone and tri-n-octylphosphine oxide in aqueous 0.2% Triton X-100 solution at pH 3.6 is used to determine europium (1.5–760 ng ml^-1) or samarium (15–1500 ng ml^-1). The excitation wavelength is 352 or 372 nm; the emission wavelength is 613 or 561 nm. The procedures give better sensitivity than the corresponding extraction methods. A standard addition method is used to overcome interferences.