Ethyl Arachidate: Properties, Uses & FAQs

Ethyl arachidate is a saturated C20 fatty acid ethyl ester derived from eicosanoic (arachidic) acid, widely used as a chromatographic reference standard in lipid analysis and metabolomics research.

Chemical Name

Ethyl eicosanoate (Ethyl arachidate)

Fatty Acid Chain

C20:0 — fully saturated, straight-chain

SKU / Catalog Number

E1492737

Reference / Equivalent

Nu-chek N-20-E

Compound Class

Fatty acid ethyl ester (FAEE)

Recommended Storage

Store under inert atmosphere at 2–8 °C, away from light and moisture

What Is Ethyl Arachidate?

Ethyl arachidate, systematically named ethyl eicosanoate, is the ethyl ester of arachidic acid (eicosanoic acid), a 20-carbon saturated fatty acid. It belongs to the fatty acid ethyl ester (FAEE) class of lipids. At room temperature it is a white to off-white waxy solid with low volatility, characteristic of long-chain saturated esters. Its molecular formula is C₂₂H₄₄O₂ and its molecular weight is approximately 340.58 g/mol.

In biological systems, fatty acid ethyl esters including ethyl arachidate can form via non-oxidative ethanol metabolism. As a pure reference compound, ethyl arachidate is primarily valued in analytical and lipidomics research rather than as a bulk reagent. Aladdin Scientific supplies this compound under SKU E1492737, equivalent to Nu-chek reference material N-20-E.

Key Physicochemical Properties

Ethyl arachidate is characterised by its fully saturated 20-carbon acyl chain, which confers a relatively high melting point compared with unsaturated fatty acid esters of similar chain length. Key properties include:

• Molecular Formula: C₂₂H₄₄O₂
• Molecular Weight: ~340.58 g/mol
• CAS Number: 1120-28-1
• Appearance: White to off-white waxy solid
• Solubility: Soluble in common organic solvents such as chloroform, hexane, and diethyl ether; poorly soluble in water
• Purity: High-purity reference grade (consult Certificate of Analysis for lot-specific data)

These properties make it amenable to gravimetric standard preparation and GC-based quantification.

Research and Analytical Applications

Ethyl arachidate serves several roles in life-science and analytical research:

1. GC and GC-MS Reference Standard: As a well-characterised C20:0 FAEE, it is routinely used to calibrate retention indices and confirm peak identities in fatty acid profiling by gas chromatography. It anchors the even-carbon saturated FAEE series used in Kovats/FAME retention index systems.
2. Lipidomics and Metabolomics: Used as an external or internal standard for quantification of fatty acid ethyl esters in plasma, tissue, and food matrices, particularly in studies of ethanol metabolism and lipid trafficking.
3. Method Development and Validation: Provides a stable, high-purity reference point for developing and validating HPLC, TLC, and GC methods for lipid analysis.
4. Food and Nutritional Science: Employed in authenticity testing of edible oils and assessment of FAEE content in food-grade ethanol products.

All applications benefit from the compound's high purity and batch-to-batch consistency as a certified reference material equivalent to Nu-chek N-20-E.

Storage, Handling and Safety

Storage: Ethyl arachidate should be stored at 2–8 °C under an inert atmosphere (e.g., nitrogen or argon) and protected from light and moisture. When stored correctly, the compound is stable for an extended period; refer to the product label and Certificate of Analysis for the recommended use-by date.

Handling: Use standard laboratory precautions. Work in a well-ventilated area or fume hood when handling organic solvent solutions. Wear appropriate personal protective equipment (PPE) including gloves, lab coat, and eye protection. Avoid inhalation of dust or vapours from solutions.

Disposal: Dispose of waste material in accordance with local regulations for organic chemical waste. Do not pour organic solvent solutions down the drain.

Flammability: The compound itself has low flammability, but solutions prepared in hexane, chloroform, or diethyl ether carry the flammability hazard of those solvents. Keep away from open flames and ignition sources.

Always consult the Safety Data Sheet (SDS) for complete hazard information before use.

Ordering and Procurement

Ethyl arachidate is available from Aladdin Scientific under SKU E1492737. This product is equivalent to Nu-chek reference material N-20-E, making it suitable as a direct replacement in protocols specifying that reference.

How to order: Place your order directly through the Aladdin Scientific website or contact your regional sales representative. Bulk quantities and custom packaging may be available upon request; please enquire with our sales team.

Documentation: A Certificate of Analysis (CoA) is available for each lot. Please request the CoA corresponding to your specific lot number to confirm purity, identity testing results, and recommended storage conditions.

Shipping: The product is shipped at ambient or cold-chain conditions depending on destination requirements and applicable regulations. Contact Aladdin Scientific customer service for specific shipping options to your location.

Frequently asked questions

What is the CAS number for Ethyl arachidate?

The CAS registry number for Ethyl arachidate (ethyl eicosanoate) is 1120-28-1. This number can be used to confirm chemical identity when cross-referencing with other suppliers or databases.

Is Ethyl arachidate (SKU E1492737) equivalent to Nu-chek N-20-E?

Yes. Aladdin Scientific's Ethyl arachidate (SKU E1492737) is specified as equivalent to Nu-chek reference material N-20-E. Researchers using Nu-chek N-20-E in existing protocols can substitute this product directly, subject to verification of lot-specific purity via the Certificate of Analysis.

What solvents are suitable for dissolving Ethyl arachidate?

Ethyl arachidate dissolves readily in non-polar and mildly polar organic solvents, including hexane, chloroform, diethyl ether, and toluene. It is not appreciably soluble in water. For GC standard preparation, hexane or iso-octane are typically preferred.

How should Ethyl arachidate be stored to maintain stability?

Store Ethyl arachidate at 2–8 °C under an inert atmosphere (nitrogen or argon), protected from light and moisture. Under these conditions the compound is stable for an extended period. Always check the lot-specific Certificate of Analysis for the recommended use-before date and any additional storage instructions.

What analytical techniques are compatible with Ethyl arachidate as a reference standard?

Ethyl arachidate is compatible with gas chromatography (GC), GC-MS, HPLC, and TLC-based lipid analysis methods. It is most commonly used in GC-FID and GC-MS workflows for fatty acid ethyl ester profiling, where it serves as a retention index anchor for the C20:0 FAEE position.

Can Ethyl arachidate be used in food authenticity testing?

Yes. Ethyl arachidate is used as a reference standard in food science laboratories for the authentication of edible oils and assessment of fatty acid ethyl ester content in food products. Its high purity and well-documented chromatographic behaviour make it suitable for regulatory and quality-control testing.

References

1. Nu-Chek Prep, Inc. Fatty Acid Reference Standards Catalogue. N-20-E: Ethyl eicosanoate (Ethyl arachidate). Elysian, MN, USA.
2. Christie WW. Lipid Analysis: Isolation, Separation, Identification and Lipidomic Analysis. 4th ed. Oily Press, 2012.
3. Gunstone FD, Harwood JL, Dijkstra AJ (eds). The Lipid Handbook. 3rd ed. CRC Press, 2007.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.