SIST EN ISO 12966-2:2017 PDF

Overview

EN ISO 12966-2:2017 - "Animal and vegetable fats and oils - Gas chromatography of fatty acid methyl esters - Part 2: Preparation of methyl esters of fatty acids" (CEN adopted) specifies validated procedures for preparing fatty acid methyl esters (FAMEs) from animal and vegetable fats and oils, fatty acids and soaps. The standard defines four methylation/transmethylation routes to produce FAMEs suitable for downstream analysis by gas chromatography (GC/GLC), thin‑layer chromatography (TLC) and infrared spectrometry (IR). Note: milk and milk products are excluded from this edition.

Key topics and technical requirements

• Scope and applicability
  • Methods designed for a wide range of edible and technical fats and oils, including distillates and acid oils (except milk fats).
• Four specified methylation/transmethylation methods
  • Rapid alkaline transmethylation - quick alkali-catalysed conversion of glycerides in anhydrous methanol; suitable for routine analyses including short-chain fatty acids (e.g., C4:0, C6:0) when an internal standard is used.
  • General sequential (alkaline then acid) method - combines alkali and acid steps to esterify both esterified and free fatty acids; applicable to challenging samples.
  • BF3 (boron trifluoride) transmethylation - acid-catalysed procedure using BF3 reagents for robust methylation in specific matrices.
  • Acid‑catalysed transmethylation of glycerides - alternative acid methylation route for glyceride-rich samples.
• Analytical considerations
  • Importance of excess anhydrous methanol to drive equilibrium toward FAMEs.
  • Water impedes completeness (hydrolysis, soaps formation); sample drying and water control are required.
  • Alkali catalysis does not esterify free fatty acids (soaps may form); sequential acid steps or BF3 are used when free fatty acids are present.
  • Guidance on reagents, apparatus, procedural steps and completeness checks (e.g., TLC annex for derivatization verification).
• Quality and reproducibility
  • Procedures include sample preparation, reagent handling and precautions to avoid artefact formation or isomerization that would bias GC results.

Applications and users

• Who uses the standard
  • Analytical chemists, food testing and regulatory laboratories, oil & fat industry quality control, research labs assessing lipid composition.
• Typical applications
  • Preparation of FAMEs for GC-based fatty acid profiling, authenticity testing, nutritional labelling, process monitoring, and research on lipid composition.
  • Pre‑treatment step for TLC and IR analyses where methyl esters improve chromatographic and spectrometric performance.

Related standards

• EN ISO 12966 is a multipart series; other parts cover GC analysis, column selection and identification/quantification of FAMEs (see ISO/CEN publications for the complete ISO 12966 series).

Keywords: EN ISO 12966-2:2017, fatty acid methyl esters, FAMEs, transmethylation, methylation, BF3, gas chromatography, animal and vegetable fats and oils, sample preparation.