1991 Volume 7 Issue 6 Pages 925-929
Reaction conditions in rare earths(RE)-Xylenol Orange(XO)-cationic surfactant ternary system were studied in detail. Conditional molar absorptivities up to 150000mmol-1 cm2 were reached. Highly sensitive spectrophotometric method for 15 RE elements (REE) was evaluated under optimal conditions of 0.06mmol dm-3 XO, 0.6mmol dm-3 cetylpyridinium bromide, and 0.01mol dm-3 acetate buffer of pH 4.50. Calibration plots measured at 600, 610, and 620nm were linear up to 5.5μmol dm-3 REE. The best detection limits of 0.04-0.20 μmol dm-3 REE were reached at 610nm. In comparison with the previous results, the sensitivity of determination was increased and the range of knowledge of the mentioned ternary system was extended.