Micellar-Enhanced Highly Sensitive Reaction of Rare Earths with Xylenol Orange and Surfactants. Study of Reaction Conditions and Optimization of Spectrophotometric Method

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