
Sodium Selenite Pentahydrate (CAS No. 26970-82-1) is a white, crystalline inorganic selenium compound with the molecular formula Na₂SeO₃·5H₂O. It is freely soluble in water and is used as a source of selenium in pharmaceutical formulations, dietary supplements, and animal feed additives. Its well-defined composition and water solubility make it useful in formulations where accurate selenium content is important.
| PRODUCT SPECIFICATIONS | |
|---|---|
| Name of Product | Sodium Selenite Pentahydrate |
| IUPAC Name | Disodium selenite pentahydrate |
| Synonyms | Selenious acid, Disodium salt, pentahydrate, Sodium selenite hydrate |
| CAS No | 26970-82-1 |
| Molecular Formula | Na2SeO3·5H2O |
| Molecular Weight | 263.03 g/mol |
| PubChem CID | 134930 |
| Grade | BP, Ph. Eur. |
| WHO-GMP | ✓ |
| US-DMF | ✓ |
| EU-WC | In process |
| S. No. | Criteria | Specifications |
|---|---|---|
| 1. | Appearance | White or almost white, crystalline, hygroscopic powder |
| 2. | Solubility | Freely soluble in water and practically insoluble in ethanol (96%) |
| 3. | IDENTIFICATION TEST | |
| Test A | A red precipitate forms, which may turn black upon standing, indicating the presence of sodium selenite | |
| Test B | The solution remains clear, indicating no precipitation | |
| Test C | A dense white precipitate forms upon adding, confirming the presence of sodium ions | |
| Test D | The sample complies with the specified assay limits | |
| 4. | Appearance of Solution (E) | Clear and colorless solution, free from visible particles or coloration |
| 5. | pH | 9.8 - 10.8 |
| 6. | Chlorides | NMT 50 ppm |
| 7. | Sulfates and Selenates | NMT 300 ppm |
| 8. | Iron | NMT 50 ppm |
| 9. | Assay (By Titration) | NLT 98.5% and NMT 101.5% of Na2SeO3.5H2O |
| 10. | MICROBIOLOGICAL TESTS | |
| Total Aerobic Microbial Count (TAMC) | NMT 1000 CFU/g | |
| Total Yeast and Mold Count (TYMC) | NMT 100 CFU/g | |
| Escherichia coli | Absent/g | |
| Salmonella enterica | Absent/10 g | |
| Staphylococcus aureus | Absent/g | |
| Pseudomonas aeruginosa | Absent/g | |
| Candida albicans | Absent/g | |
| Bacterial Endotoxin Test (BET) | NMT 0.35 EU/mcg | |
Sodium Selenite Pentahydrate is hygroscopic and should be stored in tightly closed containers, protected from moisture. As a toxic selenium compound, it should be handled with appropriate protective equipment, avoiding inhalation of dust, ingestion, and direct contact with skin or eyes. Refer to the Safety Data Sheet (SDS) for detailed handling and storage instructions.
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Q. Is Sodium Selenite bad for dogs?
Sodium selenite is used as a source of essential selenium in dog food. It is generally safe at regulated dietary levels, but excessive intake can cause selenium toxicity in dogs.
Q2. What is Sodium Selenite Pentahydrate used for?
Sodium Selenite Pentahydrate is used as a source of selenium in pharmaceutical and nutritional formulations. It also has applications in animal nutrition and selected industrial processes.
Q3. What is the CAS number of Sodium Selenite Pentahydrate?
The CAS number of Sodium Selenite Pentahydrate is 26970-82-1, and its molecular formula is Na₂SeO₃·5H₂O.
Q4. What is the difference between Sodium Selenite Anhydrous and Sodium Selenite Pentahydrate?
Sodium Selenite Anhydrous (CAS 10102-18-8) contains no water of crystallisation, whereas Sodium Selenite Pentahydrate (CAS 26970-82-1) contains five water molecules per formula unit. Their molecular weights and selenium concentrations differ.
Q5. Is Sodium Selenite Pentahydrate soluble in water?
Yes. Sodium Selenite Pentahydrate is freely soluble in water and practically insoluble in ethanol (96%).
Q6. Where can I buy Sodium Selenite Pentahydrate Ph. Eur./BP?
Macsen Labs is an Indian manufacturer and supplier of Sodium Selenite Pentahydrate Ph. Eur./BP for pharmaceutical applications. Contact Macsen Labs for product specifications, quality documentation, pricing, and bulk supply enquiries.
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