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The manifold enhancement of the rhodium extraction efficiency from nitric acid solutions of triaquatrinitrorhodium is discovered with the use of two-component mixed extractants based on alkylaniline (AA), dihexyl sulfide (DHS), dihexyl sulfoxide (DHSO), tributyl phosphate (TBP), and oxime ACORGA P5100. A mixture of unimolar solutions of alkylanilinium nitrate and DHS is found to be the most efficient extractant: at 35°C, this mixture quantitatively extracts rhodium within 5 min from aqueous solutions containing 0.06 to 3 mol/L HNO3. The extraction kinetics are studied. The following two-stage extraction mechanism is substantiated: the equilibrium of formation of a colloidal-chemical intermediate involving [Rh(H2O)3(NO2)3], HNO3, and (BHNO3)p (an associated form of the alkylanilinium salt) and the reaction of the intermediate with DHS (the rate-controlling stage).

The article summarizes experiments performed on the extraction of palladium from spent nuclear fuels. Palladium extraction from high-level nitric acid solutions was performed using diesel fuels and petroleum sulfides. Petroleum sulfide extraction systems with aromatic solvents provided the highest selectivity for palladium. Experimental results for refinement of palladium after extraction are also summarized. 14 refs., 4 tabs.

A method for the preparation of [Pd(NH3)4Cl2]Cl2 through the oxidation of [Pd(NH3)4]Cl2 with a mixture of HCl and HNO3 acids (3 : 1) in an aqueous-ammonia solution was proposed. The composition of the product was confirmed by X-ray diffraction and chemical analyses and IR and Raman spectroscopy. The yield of the product was higher than 90%, and the content of the main substance was estimated as at least 95%. The crystallographic parameters of [Pd(NH3)4Cl2]Cl2 were determined. The salt was found to be isostructural to Gros salt [Pt(NH3)4Cl2]Cl2.

The study was undertaken to estimate the capacities of triplex ultrasound angioscanning in patients with lower extremity varicose veins in the late period after phlebectomy. Seventy patients operated on for the underlying disease were examined. According to the duration of the underlying disease, all the patients were divided into 4 groups: 1) 4 (5.7%) patients had a 5-year history of lower limb varicose veins; 2) 16 (22.9%) had a 5-to-15-year history; 3) 42 (60%) had a 15-to-25-year history; 4) 8 (11.4%) had a more than 25-year history. The ultrasonic marker of recurrent lower limb varicose veins was the re-emergence of dilated saphenous and perforating veins, as well as valve apparatus failure in the operated leg. In groups 1, 2, and 3, a recurrence of the underlying disease was detected just 2 years after surgical treatment. Good results could be obtained with multimodality treatment: phlebosclerotherapy at early stages of the disease, followed by phlebectomy, or multiple phlebosclerotherapy from the earliest stages. Ultrasound study (USS) is the most rational method for screening diagnosis in case of abnormal veins of the lower extremities in the postoperative period. USS carried out at early disease stages and in the postoperative period permits prevention of recurrent lower limb varicose veins.