Support Loading Effect on Extraction Chromatography Separation of Ytterbium and Lutetium Using 2-Ethylhexylphosphonic Acid Mono-2-ethylhexyl Ester Based Sorbent

The effect of the extractant content on the efficiency of ytterbium and lutetium separation from nitric acid solutions was studied for a sorbent made by impregnating Prefilter resin with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester. It is shown that the distribution ratios of Yb and Lu and their retention coefficients in the column increase as the extractant content increases. At the nitric acid concentration of 1.5 M, the effective separation of Yb and Lu is provided by the sorbent containing at least 40 wt % extractant. When separating equal amounts of Yb and Lu (0.5 mg each) in a column with 10 cm³ of sorbent at an elution rate of 1 mL/min and a temperature of 50°C, the yield of lutetium in the purified fraction exceeds 85%, providing Yb relative content in the Lu fraction less than 0.14% (1 atom of Yb per 700 atoms of Lu).