[en] Studied is the extraction of nitrozonitrate complexes of ruthenium(¹⁰⁶Ru)from nitric acid solutions with bifunctional P-, N-containing extragents using as an example aminosubstituted phosphinoxides and their derivatives: Ph₂P(O)CH₂N(C₈H₁₇); Ph₂B(O)C₂H₄N(C₈H₁₇)₂; (C₄H₉O)₂P(O)C₂H₄N(C₈H₁₇)₂. For the comparison the extraction data have been obtained with the use of monofunctional compounds: (C₈N₁₇)₃P=0; (C₈H₁₇)₃N and equimolar mixture (C₈H₁₇)₃P=O+(C₈H₁₇)₃N. It has been established that β-APhO (for instance, Ph₂P(O)C₂H₄N(C₈H₁₇)₂) possesses a higher extraction ability as to ruthenium as compared with monofunctional analogs and their mixtures in the whole concentration range of nitric acid. The mechanism of ruthenium extraction is discussed. It has been shown that both functional groups participate in the formation of the complex under extraction. The experimental data obtained with the aid of infrared spectroscopy permit to assume that the extraction mechanism can be related to the insertion of the extragent molecules into the inner sphere of the complex with the displacement of water molecules