Arsen-74 (⁷⁴As)

Data nuklida

Unsur

Arsen (As, Z = 33)

Nomor massa (A)

74

Proton (Z)

33

Neutron (N)

41

Massa atom

73.923928596 ± 0.000001817 u

Waktu paruh

17,77 hari (± 0,02 hari)

Mode peluruhan

Peluruhan beta plus (β⁺) ( 66 %), Peluruhan beta minus (β⁻) ( 34 %)

Inti anak

Germanium-74 (⁷⁴Ge), Selenium-74 (⁷⁴Se)

Tahun penemuan

1938

Sumber data

IAEA Atomic Mass Data Center (NUBASE) and IUPAC CIAAW, via PubChem

Kegunaan isotop arsen

• 73As and 76As (with half-lives of 80.3 days and 1.1 days, respectively) are important radioactive tracers used in environmental and biomedical studies to quantify arsenic uptake. 74As (with a half-life of 17.8 days) has been used to investigate the biotransformation (modification of a chemical compound by an organism) of arsenate by mammals. In one study rabbits were injected with 74As-labeled arsenate. After a given amount of time, blood and blood products were sampled and tested for the presence and quantity of labeled arsenate metabolites. Inhalation of dust or smoke containing 74As is thought to be a causal agent of lung cancer. In one study, the “absorption rate from the bronchial tree (a respiratory tract, which conducts air into the lungs) was rapid for the first several days and then tapered off slowly. In three patients an average of 45 percent of the inhaled arsenic was eliminated in the urine in 10 days and about 0.5 percent in the stools. The remainder must be assumed to have been deposited in the body, exhaled, and/or eliminated in body secretions and excreta over a long period of time.” See Fig. IUPAC.33.1.
• 72As (with a half-life of 26 h) and 74As are useful in molecular imaging because they are radioactive isotopes that emit positrons that can be designed to bind to monoclonal antibodies (moAb), which accumulate in tumors and then 72As- or 74As-labeled ligands will bind to the moAbs. Once the 72As- or 74As-labeled ligand binds to the moAb, positron emission tomography (PET) is used to visualize the exact location of the tumor. A specific example of using radiolabeled antibodies for better imaging of tumors is the combination of 74As with bavituximab, which is an antibody that binds strongly to unique lipids on the surface of tumors. When a thiol group is introduced to bavituximab, arsenic is able to bind covalently, creating a simple and elegant radio-label for targeting cancerous tumors.

Isotop arsen lainnya

⁶⁰As, ⁶¹As, ⁶²As, ⁶³As, ⁶⁴As, ⁶⁵As, ⁶⁶As, ⁶⁷As, ⁶⁸As, ⁶⁹As, ⁷⁰As, ⁷¹As, ⁷²As, ⁷³As, ⁷⁵As, ⁷⁶As, ⁷⁷As, ⁷⁸As, ⁷⁹As, ⁸⁰As, ⁸¹As, ⁸²As, ⁸³As, ⁸⁴As, ⁸⁵As, ⁸⁶As, ⁸⁷As, ⁸⁸As, ⁸⁹As, ⁹⁰As, ⁹¹As, ⁹²As

Pelajari

Kimia inti Simulasi peluruhan ⁷⁴As Bagan nuklida