The synthesis of tritium-labelled vitamin B-6

Specimens of pyridoxine (B-6 vitamin) labelled by tritium are obtained due to techniques of liquid-phase and solid-phase heterogeneous isotopic exchange with gaseous tritium over palladium catalysts. [3H] molar activity of the vitamin obtained due to liquid-phase exchange constitutes 925-1295 TBq/mole, due to solid-phase one - 1.85-2.96 PBq/mole. 60 % of tritium are localized in 2-CH3-group, 25 % - in 4-C2HOH-group, 15 % - in 6H in the vitamin specimen obtained due to liquid-phase exchange, while at solid-phase exchange it is localized respectively as 36, 37 and 25 %