Effect of oxygen on the reduction of pertechnetate by stannous ion.

The effect of oxygen on the reduction of sodium pertechnetate by stannous chloride has been investigated using a paper electrophoresis method. It has been shown that oxygen interferes with the reduction process by oxidizing stannous ion, Sn(II), to stannic, Sn(IV), thereby leaving less Sn(II) available for the reduction of pertechnetate ion. In a solution of 1.66 X 13(-3)M TcO4- saturated with oxygen, a 3.4 molar ratio of Sn(II) to TcO4- was required for complete reduction of TcO4-, whereas in a nitrogen atmosphere, a 2.4 molar ratio was required for the same purpose. The oxygen interference increases as the concentration of TcO4- decreases. In a nitrogen atmosphere, 1.40 and 10.05 molar ratios of Sn(II) to TcO4- were required for the complete reduction of 1.66 X 10(-2)M and 1.66 X 10(-5)M TcO4- respectively. Once the reduction is accomplished, however, it is not easily reversible. Bubbling with oxygen for 1 hr had no effect on the quantity of reduced technetium.