Biomaterial Database

Understanding the radiolabelling mechanism of 99mTc-antimony sulphide colloid. 2003

Chris Tsopelas

RAH Radiopharmacy, Nuclear Medicine Department, Royal Adelaide Hospital, North Terrace, Adelaide 5000, Australia. ctsopela@mail.rah.sa.gov.au

The chemistry of antimony trisulphide colloid (ATC) was examined to elucidate the radiolabelling mechanism with 99mTcO4(-). Ion exchange chromatography and atomic absorption spectrophotometry techniques determined ATC to be resistant to hydrolysis in 0.1M hydrochloric acid (HCl) at 25 degrees C or 100 degrees C (>97% recovery, Sb3+ absent). Hydrogen sulphide gas detected did not participate in the mechanism, where antimony trisulphide and 99mTcO4(-) in HCl/100 degrees C yielded 96% 99mTc-product from a K2S-free formulation (versus 98% when K2S was present). 99mTcO4(-) was reduced >90% by DMSA or dithiothreitol under the same conditions, identifying involvement of thiol groups. Infrared analysis of Re-ATC showed S=O bonds, indicating excess thiol groups at the colloid surface were oxidised at the expense of 99mTcO4(-) reduction.

UI	MeSH Term	Description	Entries
D007553	Isotope Labeling	Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.	Isotope Labeling, Stable,Isotope-Coded Affinity Tagging,Isotopically-Coded Affinity Tagging,Affinity Tagging, Isotope-Coded,Affinity Tagging, Isotopically-Coded,Isotope Coded Affinity Tagging,Labeling, Isotope,Labeling, Stable Isotope,Stable Isotope Labeling,Tagging, Isotope-Coded Affinity,Tagging, Isotopically-Coded Affinity
D000965	Antimony	A metallic element that has the atomic symbol Sb, atomic number 51, and atomic weight 121.75. It is used as a metal alloy and as medicinal and poisonous salts. It is toxic and an irritant to the skin and the mucous membranes.
D013440	Sulfides	Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.	Sulfide,Thioether,Thioethers,Sulfur Ethers,Ethers, Sulfur
D013667	Technetium	The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, and atomic number 43. All technetium isotopes are radioactive. Technetium 99m (m	Technetium 99m,99m, Technetium
D013670	Sodium Pertechnetate Tc 99m	A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in the gastrointestinal system, cardiovascular and cerebral circulation, brain, thyroid, and joints.	Pertechnetate Sodium,Tc 99m-Pertechnetate,Technetium Tc 99m Pertechnetate,99Tc-Pertechnetate,99TcmO4,99mTcO4,Pertechnetate,Technetium Pertechnetate,Technetium Tc 99m O(4),Technetium-99mTc-pertechnetate,99Tc Pertechnetate,99m-Pertechnetate, Tc,Pertechnetate, Technetium,Sodium, Pertechnetate,Tc 99m Pertechnetate,Technetium 99mTc pertechnetate
D013671	Technetium Tc 99m Sulfur Colloid	A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in the gastrointestinal system, liver, and spleen.	Tc-99m Sulfur Colloid,Technetium Sulfur Colloid,Lymphoszint,Tc 99m Sulfur Colloid,Colloid, Tc-99m Sulfur,Colloid, Technetium Sulfur
D019275	Radiopharmaceuticals	Compounds that are used in medicine as sources of radiation for radiotherapy and for diagnostic purposes. They have numerous uses in research and industry. (Martindale, The Extra Pharmacopoeia, 30th ed, p1161)	Radiopharmaceutical