Solvent extraction of pertechnetate anions from aqueous solutions of some mineral acids (HC1, HNO3, HC104, H2SO4) , (NaC1, NaNO3, NaC104, K2CrO4, NaCO3), NaOH and NH4OH by tetraphenylphosphonium chloride in chloroform and nitrobenzene was studied. The results are presented in the form of the dependencies of extraction characteristics of TcO 4 (distribution ratio, percentage of extraction) on the (C6Hs)4PC1, H + and competitive anion concentrations. The solvent extraction of sub-and super-stoichiometric ratio of TcO4:(C6H5)4 P+ was performed. The extraction constant values of ion pairs TcO~C1 , TcO 4 NO3, TcO~C104 and of individual anions TcO4, C1 , NO3, C104 were calculated.

The extraction of pertechnetate in form of ionogene associates with triphenyltin and trioctyltin cations into chloroform, benzene, toluene and nitrobenzene was studied. As aqueous phases solutions of 99mTcO4 in deionized water and in diluted solutions of NaC1, HC1, NaNO3, HNO 3 NaC10+ HC104 and NaOH were used. Concerning the organic phases, at the use of triphenyltin chloride the extractibility of pertechnetate increases in the sequence: toluene (~ chloroform, benzene < nitrobenzene and approximately in the sequence: NaOH < NaC1, HC1 < NaNO3< H20 < NaC104 concerning aqueous phases. For trioctyltin chloride in chloroform the extractibility of TcO 4 increases approximately in the sequence of aqueous phases : NaOH < HC1, NaNO3, NaC104, NaC1 (~ H20 and in nitobenzene in the sequence NaOH < NaC104< HC1 < NaNO3, NaC1 (~ H20. The extractibility for trioctyltin chloride is in general slightly lower as compared with triphenyltin chloride. The results of the extraction are presented in the form of graphical plots of technetium distribution ratio (DTc, log DTc ) or extraction yield (ETc, %) against concentration of the investigated component in aqueous or organic phase. In some of the systems studied practically quantitative extraction ofpertechnetate into organic phase has been achieved.

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Conductivity of tetraphenylarsonium chloride (Ph4AsC1), tetraphenylphosphonium chloride (Ph4PC1), tetraphenylarsonium pertechnetate (Ph4AsTcO4), tetraphenylphosphonium pertechnetate (Ph4PTcO4) , triphenyltin chloride (Ph3SnC1) and trioctyltin chloride (Oct3SnC1) solutions in nitrobenzene and chloroform was studied. On the basis of determined molar conductivity A values at different concentrations of the electrolyte in solution, values of dissociation degree of the electrolyte ~x, molar conductivity at infinite dilution A 0 and dissociation costant K i for compounds of type Ph4(As or P) (C1 or TcO4) were calculated. It was shown that for some of the investigated systems the Kohlrausch's empirical relation applies. In chloroform solutions a parabolic dependence of molar conductivity on electrolyte concentration was observed which testifies that a formation of ion triplets at higher electrolyte concentration can occur.