Sodium iodide (chemical formula NaI) is an ionic compound formed from the chemical reaction of sodium metal and iodine. Under standard conditions, it is a white, water-soluble solid comprising a 1:1 mix of sodium cations (Na+) and iodide anions (I−) in a crystal lattice. It is used mainly as a nutritional supplement and in organic chemistry. It is produced industrially as the salt formed when acidic iodides react with sodium hydroxide. It is a chaotropic salt.
Sodium iodide, as well as potassium iodide, is commonly used to treat and prevent iodine deficiency. Iodized table salt contains 10 ppm iodide.
Sodium iodide activated with thallium, NaI(Tl), when subjected to ionizing radiation, emits photons (i.e., scintillate) and is used in scintillation detectors, traditionally in nuclear medicine, geophysics, nuclear physics, and environmental measurements. NaI(Tl) is the most widely used scintillation material. The crystals are usually coupled with a photomultiplier tube, in a hermetically sealed assembly, as sodium iodide is hygroscopic. Fine-tuning of some parameters (i.e., radiation hardness, afterglow, transparency) can be achieved by varying the conditions of the crystal growth. Crystals with a higher level of doping are used in X-ray detectors with high spectrometric quality. Sodium iodide can be used both as single crystals and as polycrystals for this purpose. The wavelength of maximum emission is 415 nm.
Chemical Properties Of Reagent Grade Sodium Iodide Granules For Sale Online At LabAlley.com
CAS Number | 7681-82-5 |
Molecular Formula | NaI |
Formula Weight | 149.89 |
Assay (Nal) | Min. 99.0% |
Alkalinity (as Na2CO3) | 0.02% |
Barium (Ba) | 0.002% |
Chloride and Bromide (asCl) | 0.01% |
Heavy Metals (as Pb) | 5 ppm |
Insoluble | 0.01% |
Iodate (IO3) | 3 ppm |
Iron (Fe) | 5 ppm |
Phosphate (PO4) | 0.001% |
Sulfate (SO4) | 0.005% |
Uses/Applications
NaI(Tl) crystals are widely used for radiation detection:
- Medical – SPECT (gamma camera), whole-body counting, radioimmunoassay (RIA)
- Security – Thermal neutron activation
- Industrial – Thickness or density gauging, coal/mineral assy
- Oil and gas exploration – well logging
- Environmental monitoring
- Aerial survey
- Nuclear physics
Features/Benefits
- High light output
- Available in single-crystal & polycrystalline form
- No significant self-absorption of scintillation light
- Emission spectrum well matched with the sensitivity curve of photomultiplier tubes (PMTs) with bialkali photocathodes
Please contact us to request a Safety Data Sheet (SDS) and Certificate of Analysis (COA) for Sodium Iodide Granular Reagent.