Solvent extraction studies using tetracycline as complexing agent

The behaviour of tetracycline as an extracting agent for strontium, iodine, barium, molybdenum, technetium, zirconium, niobium, cesium, ruthenium, tellurium and uranium has been studied and the influence of the acidity of the aqueous phase upon extraction of the elements mentioned has been examined. Experiments have been made to determine whether or not the species extracted into the organic phase is the complex formed between tetracycline and the elements considered as well as to determine the time of shaking necessary so that the equilibrium between the phases is attained. As a practical application, the possibility of using the tetracycline-benzyl alcohol system for separating the fission products¹³⁷Cs,¹⁴⁰Ba,¹⁴⁰La,¹⁴¹Ce,¹⁰³Ru,⁹⁵Zr and⁹⁵Nb from each other and from uranium is presented. The same study has been made for¹³¹I,^99mTc,⁹⁹Mo,¹³²Te,²³⁹Np and uranium and the steps necessary for the separation of these elements are proposed.From a thesis submitted by I. I. L. CUNHA to the Instituto de Pesquisas Energéticas e Nucleares-University of São Paulo in partial fulfillment of the requirements for a Doctor of Science's Degree. Work supported by Comissão Nacional de Energia Nuclear.     

Solvent extraction studies using tetracycline as a complexing agent

Stability constants for uranium-tetracycline complexes were determined by the method of average number of ligands, the method of limiting values, the method of two parameters and the method of weighted least squares. Solvent extraction technique was used to obtain experimental data.     

Solvent extraction studies using tetracycline as a complexing agent

Stability constants for thorium complexes with tetracycline were determined by the methods of average number of ligands, the limiting value, the two parameters and by weighted least squares. The solvent extraction technique was used to obtain the required data for the determination of the constants. Work partly supported by the Brazilian Atomic Energy Commission.     

Solvent extraction of the lanthanide elements,scandium, uranium and thorium using tetracycline as complexing agent

Hydrogen ion dependence and extractant dependence of the extraction of the lanthanide elements, scandium, uranium and thorium into a solution of tetracycline in benzyl alcohol have been determined. Possiblity of using the tetracycline-benzyl alcohol system for separation of the lanthanide elements present in a mixture, as well as for the separation of uranium from those elements was tested. In the first case discontinuous countercurrent technique was used. In the second case a single step solvent extraction procedure was applied.     

Application of sephadex to radiochemical separations

Heteropolymolybdic acid species of a variety of elements bind to Sephadex (dextran cross-linked by epichlorohydrin). Solution pH can be used as a variable to influence the formation of heteropolymolybdates and thus their affinity for Sephadex. Therefore this material may be used to chromatographically separate certain elements which have been reacted with molybdate in solution. In this paper we report the measurement of distribution coefficients on Sephadex for heteropolymolybdates of As, P, Ge, Si, and Se for solutions of varying pH. We also describe the application of the technique to the recovery of³²Si from proton-irradiated KCl targets and⁶⁸Ge from proton-irradiated molybdenum targets.     

Solvent extraction studies using tetracycline as a complexing agent. XIII. Application of tetracycline for separation of interfering elements in activation analysis of uranium

Tetracycline in solution of benzyl alcohol was used as an extracting agent to separate uranium from interfering elements in the determination of uranium and of isotopic ratio²³⁵U/²³⁸U by neutron activation analysis. Separation gives a recovery of 97% for uranium and the interferences from matrices of pitchblende and monazite are eliminated.From a dissertation submitted by R. Petrauskas to the University of São Paulo in partial fulfilment for a Master of Science Degree in Nuclear Technology.