Sigma-Aldrich Ethylenediaminetetraacetic acid iron(III) sodium salt hydrate, 12-14% Fe basis

Ethylenediaminetetraacetic acid iron(III) sodium salt hydrate, often referred to as EDTA-FeNa, is a specialized chelating compound used for a variety of applications, including chemical analysis, environmental remediation, and laboratory research. Its formulation incorporates iron in a chelated state, stabilized with sodium and hydrated to ensure solubility and ease of handling.

Chemical Structure

• Formula: (OOCCH2)2NCH2CH2N(CH2COO)2FeNa⋅xH2O
• Molecular Weight: 367.05 g/mol
• CAS Number: 149022-26-4
• SMILES String: [Na+].[Fe+3].[O-]C(=O)CN(CCN(CC([O-])=O)CC([O-])=O)CC([O-])=O
• InChI Key: MKWYFZFMAMBPQK-UHFFFAOYSA-J

The structure consists of:

1. A central iron(III) ion (Fe3+Fe^{3+}Fe3+) bound by the ethylenediaminetetraacetic acid (EDTA) ligand.
2. A sodium ion (Na+Na^+Na+) for charge balancing.
3. Hydration molecules (xH2OxH_2OxH2​O) to maintain stability.

Physical Properties

• Appearance: Yellow to very dark yellow/brown powder or crystals.
• Solubility:
  • Soluble in hot water, with 0.5 g dissolving in 10 mL to produce a clear to slightly hazy solution.
  • Solution color varies from yellow to dark brown, depending on the concentration and conditions.
• Assay: Contains 12–14% iron by weight.
• Impurities:
  • ≤15% loss on drying, indicating the presence of water of hydration and minimal other contaminants.

Functional Properties

1. Chelation:
   • EDTA-FeNa acts as a strong chelator, binding metal ions like Fe3+Fe^{3+}Fe3+ securely within its framework.
   • This property is essential for stabilizing reactive metal ions in both chemical and biological systems.
2. Reactivity:
   • Functions as a reagent, particularly in applications requiring controlled iron release.
   • Acts as a chelator to manage metal-ion availability in systems where free iron might be detrimental or where iron needs controlled introduction.
3. Stability:
   • High thermal and chemical stability due to the chelated iron.

Applications

1. Analytical Chemistry:
   • Used in large-volume stacking with electroosmotic flow pumps (LVSEP), enhancing fluid dynamics in separation and analysis.
2. Environmental Remediation:
   • Applied in groundwater treatment to bind and immobilize contaminants, reducing their mobility and toxicity.
3. Biological Research:
   • Provides a controlled iron source for experiments requiring precise metal ion concentrations.
4. Industrial and Agricultural:
   • Acts as a micronutrient additive in fertilizers and other systems requiring bioavailable iron.

Safety and Handling

• Quality Level: 200, ensuring laboratory-grade purity.
• Storage: Keep in a cool, dry environment to prevent loss of hydration or degradation.
• Handling Precautions: Avoid inhalation and contact with skin or eyes; handle with appropriate safety measures.

Ethylenediaminetetraacetic acid iron(III) sodium salt hydrate is a versatile and reliable compound for diverse chemical and environmental applications, ensuring precise iron delivery and high stability under various conditions.