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Abstract  

Dianionic tridentate O, N, S Schiff bases derived from salicylaldehyde and 2-mercaptoamines react with Tc/V/ gluconate to form radiochemically pure neutral Tc chelates. The existence of lipophilic Tc complexes could be proved by high voltage electrophoresis, thin layer chromatography and octanol/water partition coefficients.

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Lipophilic technetium complexes

IV. Neutral, lipid-soluble technetium complexes with dithioligands containing Tc=O and Tc≡N cores. An in vitro study

Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Abram
,
U. Abram
,
H. Spies
, and
R. Münze

Abstract  

A series of technetium complexes with different alkyl dithiocarbamates, dithiophosphates and xanthates has been prepared at tracer level (10–4 molar) starting from hydrazine-reduced pertechnetate and Tc(V) gluconate, respectively. Solution studies show the complexes to be neutral, lipid-soluble tracers. Their in vitro properties can be varied in a wide range by variation of alkyl substitution of the ligands.

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Abstract  

The Tc budget in several ROTOP-generators was determined by neutron activation analysis (NAA) and UV-spectroscopy. The complete procedure included the preparation of the generator, elution cycle in 24 to 72 h intervals and evaporation of the eluates to dryness. The samples were aliquoted, irradiated in the reactor and analyzed via99Tc(n, n')99mTc 99Tc reaction as well as by UV-absorption due to pertechnetate. The most reliable method proved to be NAA including chemical separation from24Na by ion exchange after the complete decay of38Cl. The detection limit was 50 ppb (3 ng Tc), compared with the total amount of several 10–5 g down to 10–7 g Tc in the system and its fractions. The mass balance and the elution profiles obtained correspond very well to the theoretical values. The results permit further quantitative considerations on both elution kinetics and the generator system.

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Abstract  

Extraction of pertechnetate with bicyclic guanidinium compounds has been studied in the KTcO4-buffer-H2O/ligand-trichloromethane system. Extraction data of guanidinium ligands have been compared with trialkylmethylammonium (Aliquat 336), tetraphenylphosphonium and tetraphenylarsonium chloride. The lipophilicity of extractants investigated was determined by RP-HPLC. The efficiency of pertechnetate extraction correlates with the lipophilicity of the guanidinium compounds. 1:1 complex formation in the organic phase was observed. The influence of hydroxide, chloride and bicarbonate on the pertechnetate extraction has been investigated. Pertechnetate is extracted with great preference over OH, Cl and HCO3 , ions.

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Abstract  

The coupling of Re- and99mTc-MAG3 complexes with amines and nucleobases was carried out with good yields using O-(benzotriazol-1-yl-)-N,N,N',N'-tetramethyl-uronium-tetrafluoroborate (TBTU), and base in polar aprotic solvents (NMP, DMF, DMSO). The one step reaction followed by simple gel chromatography makes the method well appropriate for preparations at the low no-carrier-added level of technetium-99m.

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