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CHM.118911 - Sodium azide ≥99.5% - CAS: 26628-22-8
Sodium azide (NaN₃), with the Chemical Abstracts Service (CAS) number 26628-22-8, is a chemical compound widely used in various scientific, industrial, and medical applications. It is an inorganic salt composed of sodium (Na⁺) and azide (N₃⁻) ions. Below is a detailed overview of the usage of sodium azide in different fields:
1. Molecular Biology and Biochemistry
Sodium azide is commonly used in molecular biology and biochemistry as a preservative and inhibitor. Its applications include:
  • Preservation of Antibodies and Proteins: Sodium azide is added to antibody solutions, enzyme preparations, and protein stocks (typically at 0.02–0.1% w/v) to prevent microbial contamination. It inhibits the growth of bacteria and fungi, ensuring the stability of biological reagents.
  • Inhibition of Cytochrome c Oxidase: Sodium azide is a potent inhibitor of cytochrome c oxidase, a key enzyme in the mitochondrial electron transport chain. This property makes it useful in studying cellular respiration and oxidative phosphorylation.
  • Blocking Endocytosis: In cell biology, sodium azide is used to inhibit ATP-dependent processes, such as endocytosis, by depleting cellular ATP levels.
2. Diagnostic Applications
Sodium azide is widely used in diagnostic kits and assays, particularly in immunoassays and clinical chemistry:
  • ELISA (Enzyme-Linked Immunosorbent Assay): It is added to antibody solutions, enzyme conjugates, and wash buffers to prevent microbial growth and maintain reagent stability.
  • Lateral Flow Assays: Sodium azide is used to preserve antibodies and other biomolecules in rapid diagnostic tests.
  • Blood Gas Analyzers: It is used as a preservative in control solutions for blood gas analyzers.
3. Pharmaceutical and Medical Applications
  • Antibacterial Agent: Sodium azide has been used as an antibacterial agent in topical medications and eye drops.
  • Preservative in Intravenous Solutions: It has been used in small concentrations to preserve intravenous solutions, although its use in this context has declined due to safety concerns.
4. Industrial Applications
  • Automotive Airbags: Sodium azide is a key component in the propellant systems of automotive airbags. Upon ignition, it decomposes to produce nitrogen gas, which rapidly inflates the airbag.
  • Chemical Synthesis: Sodium azide is used as a precursor in the synthesis of other azide compounds, such as lead azide (used in detonators) and organic azides (used in click chemistry).
  • Explosives and Pyrotechnics: Due to its explosive properties, sodium azide is used in the manufacture of detonators and initiators.
5. Laboratory Safety and Waste Treatment
  • Decontamination of Laboratory Waste: Sodium azide is used to decontaminate laboratory waste by reacting with heavy metals to form insoluble metal azides.
  • Quenching Reactions: It is used to quench reactions involving peroxides and other reactive compounds.
6. Advantages of Sodium Azide
  • Effective Preservative: Sodium azide is highly effective at low concentrations (0.02–0.1% w/v) in preventing microbial growth.
  • Compatibility: It is compatible with proteins, antibodies, and enzymes, making it suitable for use in biological reagents.
  • Stability: Sodium azide is stable under normal laboratory conditions and does not degrade easily.
7. Safety and Handling
  • Toxicity: Sodium azide is highly toxic if ingested, inhaled, or absorbed through the skin. It inhibits cytochrome c oxidase, leading to cellular hypoxia.
  • Explosive Hazard: Sodium azide can form explosive metal azides when it comes into contact with heavy metals (e.g., copper, lead) or under acidic conditions.
  • Handling Precautions: Use personal protective equipment (PPE), including gloves, lab coats, and safety goggles. Work in a fume hood to avoid inhalation.
  • Disposal: Dispose of sodium azide waste according to local regulations. Neutralize azide-containing waste with sodium nitrite (NaNO₂) to convert it into non-toxic nitrogen gas.
8. Limitations
  • Cytotoxicity: Sodium azide is cytotoxic and cannot be used in cell culture media or solutions intended for live cells.
  • Interference with Assays: It may interfere with certain assays, particularly those involving peroxidase enzymes, as it inhibits their activity.
9. Regulatory Compliance
Sodium azide is regulated due to its toxicity and explosive properties. Its use in pharmaceuticals and diagnostics must comply with guidelines from regulatory agencies such as:
  • FDA (Food and Drug Administration): For use in diagnostic reagents and pharmaceuticals.
  • OSHA (Occupational Safety and Health Administration): For workplace safety and handling.
10. Alternatives
Due to its toxicity and safety concerns, alternatives to sodium azide are sometimes used, such as:
  • ProClin 300: A less toxic preservative for biological reagents.
  • Thimerosal: A mercury-based preservative used in vaccines and diagnostics.

CHM.118911 - Sodium azide ≥99.5% - CAS: 26628-22-8

SKU: CHM.118911
€13.00Price
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Will ship 7-14 days from Malta.

  • 1. Molecular Structure

    • Chemical Formula: NaN₃

    • Molecular Weight: 65.01 g/mol

    • Structure: Sodium azide consists of sodium cations (Na⁺) and azide anions (N₃⁻). The azide ion is linear, with a central nitrogen atom bonded to two terminal nitrogen atoms (N⁻=N⁺=N⁻).

    2. Physical Properties

    • Appearance: White crystalline solid or powder.

    • Odor: Odorless.

    • Density: 1.846 g/cm³ at 25°C.

    • Melting Point: 275°C (527°F) (decomposes before melting).

    • Solubility: Highly soluble in water (420 g/L at 20°C). Soluble in liquid ammonia. Insoluble in organic solvents like ethanol and ether.

    • pH: Neutral (pH ~7 in aqueous solution).

    3. Chemical Stability

    • Thermal Stability: Sodium azide is stable at room temperature but decomposes explosively when heated above 300°C, releasing nitrogen gas (N₂).

    • Light Sensitivity: Stable under normal lighting conditions but may decompose under prolonged exposure to UV light.

    • Reactivity with Acids: Reacts with acids to produce hydrazoic acid (HN₃), a highly toxic and explosive gas.

    • Reactivity with Metals: Reacts with heavy metals (e.g., copper, lead, mercury) to form metal azides, which are highly explosive.

    4. Reactivity

    • Decomposition: Sodium azide decomposes upon heating or impact, producing nitrogen gas and sodium metal:

      2NaN3→2Na+3N22NaN3​→2Na+3N2​

      This reaction is utilized in automotive airbags to rapidly inflate the airbag during a collision.

    • Oxidation: Sodium azide can be oxidized by strong oxidizing agents, such as potassium permanganate (KMnO₄) or hydrogen peroxide (H₂O₂), to produce nitrogen gas and other byproducts.

    • Reduction: Sodium azide can be reduced to ammonia (NH₃) and nitrogen gas (N₂) by reducing agents like sodium borohydride (NaBH₄).

    5. Toxicity and Safety

    • Toxicity: Sodium azide is highly toxic if ingested, inhaled, or absorbed through the skin. It inhibits cytochrome c oxidase, a critical enzyme in cellular respiration, leading to cellular hypoxia.

    • Explosive Hazard: Sodium azide itself is not highly explosive, but it can form explosive metal azides when it comes into contact with heavy metals or under acidic conditions.

    • Handling Precautions: Use personal protective equipment (PPE), including gloves, lab coats, and safety goggles. Work in a fume hood to avoid inhalation.

    • Disposal: Dispose of sodium azide waste according to local regulations. Neutralize azide-containing waste with sodium nitrite (NaNO₂) to convert it into non-toxic nitrogen gas.

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