Unbalanced equations of technetium reduction and tagging are shown. The first equation shows the normal case, where pertechnetate (7+) is reduced (3+, 4+, 5+) by stannous chloride to enable tagging a pharmaceutical.
The second equation shows the case of air contamination. This generates free pertechnetate, which accumulates in the stomach and thyroid and salivary glands. Paper chromatography with acetone will show free pertechnetate advancing with the solvent front.
The third equation shows the case of water contamination, generating technetium dioxide ("hydrolyzed technetium") and stannous hydroxide, a colloid. Technetium dioxide will accumulate in the liver. The stannous ions may cause red blood cell labeling. Residual stannous ions in the blood may also result in inadvertant in vivo red blood cell labeling if another pertechentate scan (e.g., thyroid or Meckel) is attempted within a week.
Paper chromatography with saline as the solvent will show technetium dioxide at the origin and water soluble tracers (e.g., DTPA) advancing with the solvent front.
References
- Johnson AE, Gollan F. 99mTc-technetium dioxide for liver scanning. J Nucl Med. 1970 Sep;11(9):564-5.
- Mettler FA and Guiberteau MJ. Chapter 3. In Essentials of Nuclear Medicine Imaging. Fifth Edition. Saunders, Philadelphia. 2006. pp 44-45.
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