Stannous ion determination in99mTc radiopharmaceutical kits

Two simple and selective methods for determination of stannous ion in radiopharmaceutical kits are proposed. One of this permits the estimation of stannic ion. The first method unsed is a potentiometric titration of Sn²⁺ in HCl medium, using KIO₃ solution under nitrogen gas and a platinum redox electrode. The second method consists of a complexometric titration of tin (Sn²⁺ and Sn⁴⁺) using an EDTA standard solution at pH 5.5–5.6 without the use of nitrogen gas. The procedures employed indicate that both methods can be used for routine quantitative determination of tin in most labeled radiopharmaceuticals.