radiochemical Flashcards
What percentage of Radiopharmaceuticals are made of Tc-99m?
86%
This indicates the significance of Tc-99m in the field of radiopharmaceuticals.
What are the primary reactions involved in Tc chemistry?
- Oxidation-Reduction Reactions
- Ligand exchange
- Chelation
- Protein binding
- Sulfur-based reduction reactions
These reactions are essential for the chemical modification and application of Tc-99m in radiopharmaceuticals.
When was Technetium (Tc) predicted and discovered?
Predicted in 1925 and discovered in 1947
This highlights the historical timeline of Technetium’s identification.
What is the atomic number of Technetium?
43
Technetium is the first artificial element in the periodic table.
What group and period does Technetium belong to in the periodic table?
Period 5, Group 7B
Technetium is located among transition elements.
What is the oxidation state of Pertechnetate (NaTcO4)?
+7
Pertechnetate is the most stable form of Technetium in aqueous solution.
What is the significance of the d-orbital in Technetium’s chemistry?
Unsaturated d-orbitals allow for variable combining power and complex coordination
This characteristic leads to electropositivity and the ability to accept different numbers of electrons.
What is the half-life of Tc-97m?
90 days
This is one of the various isotopes of Technetium with different decay modes.
What is the role of reducing agents in the preparation of Tc-99m labeled Radiopharmaceuticals?
They reduce TcO4(VII) to lower oxidation states like TcO2(IV)
Common reducing agents include SnCl2 and NaBH4.
Fill in the blank: Chelating agents are complexing agents with more than one _______.
ligand
This characteristic allows them to form stable complexes with metal ions.
What types of molecules can Technetium form complexes with?
- Anions: Cl, F, OH, DMSA, DTPA, HIDA
- Cations: MIBI
- Molecules/ neutrals: H2O, ROH, CO
- Peptides, Receptor Ligands, Antibodies
This diversity allows Technetium to be utilized in various biochemical applications.
What happens when TcO4 is added to excess Sn2-DTPA mixture?
A 50:50 mixture of Tc(iii)-DTPA and Tc(iv)-DTPA is formed
The order of addition significantly affects the resulting complexes.
True or False: All Tc isotopes are radioactive with different decay modes.
True
This includes isotopes with varying half-lives.
What are Tc-99m-tagged compounds used for?
To study the biological distribution in target organs
Examples include Tc-99m-Sulfur colloids for liver function studies.
What factors influence the biological distribution of essential class radiopharmaceuticals?
- Oxidation state of Tc-99m
- Functional groups of ligand molecules
- Tc-99m-core configuration
These factors are critical for the effectiveness of the radiopharmaceuticals.
What is the expected outcome after the reduction of TcO4(VII) using Sn(II)?
A mixture of Tc(III, IV, and V) is expected
The reduction process is reversible and can be stabilized by complexing agents.
What role do sulfur-based reduction reactions play in Tc chemistry?
They form complexes that are excreted through the kidneys
Examples include DMSA and Penicillamine.
What is the primary use of Tc-99m labeled radiopharmaceuticals?
To study diseases and metabolic disorders in human tissues and organs
This application underscores the importance of Tc-99m in medical imaging.
