PT  - JOURNAL ARTICLE
AU  - Almeida, Érika V.
AU  - Lugon, Marcelo di M.V.
AU  - da Silva, José L.
AU  - Fukumori, Neuza T.O.
AU  - de Pereira, Nilda P.S.
AU  - Matsuda, Margareth M.N.
TI  - Selective Polarographic Determination of Stannous Ion in Technetium Radiopharmaceutical Cold Kits
AID  - 10.2967/jnmt.111.087437
DP  - 2011 Dec 01
TA  - Journal of Nuclear Medicine Technology
PG  - 307--311
VI  - 39
IP  - 4
4099  - http://tech.snmjournals.org/content/39/4/307.short
4100  - http://tech.snmjournals.org/content/39/4/307.full
SO  - J. Nucl. Med. Technol.2011 Dec 01; 39
AB  - The aim of this work was to develop a selective method for quantification of Sn(II) and Sn(IV) in dimercaptosuccinic acid (DMSA), ethylcysteinate dimer (ECD), methylenediphosphonic acid (MDP), and pyrophosphate radiopharmaceutical cold kits by differential pulse polarography. Methods: A dripping mercury electrode 150 polarographic/stripping analyzer with a conventional 3-electrode configuration was used with 3 M H2SO4 and 3 M HCl supporting electrolytes for Sn(II) and Sn(IV), respectively. The polarographic analysis was performed using a 1-s drop time, 50-mV·s−1 scan rate, −50-mV pulse amplitude, 40-ms pulse time, and 10-mV step amplitude. To quantify Sn(IV), oxidation of Sn(II) by H2O2 was performed. The calibration curves for Sn(II) and Sn(IV) were obtained in the range of 0–10 μg·mL−1. Results: The analytic curves for Sn(II) in 3 M H2SO4 and Sn(IV) in 3 M HCl were represented by the following equations: i (μA) = 0.098 [Sn(II)] + 0.018 (r2 = 0.998) and i (μA) = 0.092 [Sn(IV)] + 0.016 (r2 = 0.998), respectively. The detection limits were 0.21 μg·mL−1 for Sn(II) and 0.15 μg·mL−1 for Sn(IV). In DMSA, ECD, MDP, and pyrophosphate, 90.0%, 64.9%, 93.2%, and 87.5%, respectively, of the tin was present as Sn(II). In this work, selective determination of Sn(II) and Sn(IV) was achieved using 2 supporting electrolytes (H2SO4 and HCl). In 3 M H2SO4, only Sn(II) produced a polarographic wave with the maximum current in −370 mV. Under the same conditions, no current could be determined for Sn(IV). In 3 M HCl, Sn(II) and Sn(IV) were electroactive and the maximum currents of the 2 waves appeared in −250 and −470 mV. No other components of the lyophilized reagents had any influence. Conclusion: The developed polarographic method was adequate to quantify Sn(II) and Sn(IV) in DMSA, ECD, MDP, and pyrophosphate cold kits.