Abstract <p>The features of preparative extraction-chromatographic separation of microquantities of lutetium and macroquantities of ytterbium have been studied using a sorbent, based on 2-ethylhexyl hydrogen 2-ethylhexylphosphonate (HEH[EHP]). A correlation between the volume of the elution start and the sorbent loading with macro-component has been established for both macro- and micro-components. These correlations allow us to estimate the volume of the column required for preparative processing of macro-quantities target. It has been demonstrated, that effective separation is possible even at high sorbent load, leading to considerable deviations from classical (Gaussian) chromatography dependencies. It was demonstrated, that processing 300 mg of Yb using a 100 cm³ column (nearly 20% loading) is possible, allowing for separation of more than 95% of the target radionuclide and the content of matrix ytterbium in the lutetium fraction can be reduced by 83% in a single chromatographic cycle.</p>