RT Journal Article
SR Electronic
T1 Selective Polarographic Determination of Stannous Ion in Technetium Radiopharmaceutical Cold Kits
JF Journal of Nuclear Medicine Technology
JO J. Nucl. Med. Technol.
FD Society of Nuclear Medicine
SP jnmt.111.087437
DO 10.2967/jnmt.111.087437
A1 Almeida, Érika V.
A1 Lugon, Marcelo di M.V.
A1 da Silva, José L.
A1 Fukumori, Neuza T.O.
A1 de Pereira, Nilda P.S.
A1 Matsuda, Margareth M.N.
YR 2011
UL http://tech.snmjournals.org/content/early/2011/09/26/jnmt.111.087437.abstract
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.