ISO 18363-2:2025

Overview

ISO 18363-2:2025 - Animal and vegetable fats and oils - Determination of fatty-acid-bound chloropropanediols (MCPDs) and glycidol by GC/MS - Part 2 describes a laboratory method for the parallel quantification of 2‑MCPD, 3‑MCPD and glycidol (including bound and any free forms) in solid and liquid fats and oils. The method uses slow alkaline transesterification, conversion of released glycidol into monobromopropanediol (MBPD), and derivatisation of free diols with phenylboronic acid (PBA) before analysis by gas chromatography–mass spectrometry (GC/MS). Milk and milk products are excluded; animal fats and used frying oils can be analysed after validation.

Key technical topics and requirements

• Analytical principle: cold, slow alkaline-catalysed alcoholysis to release ester‑bound analytes, followed by glycidol → MBPD transformation to stabilise glycidol for GC/MS.
• Derivatisation: MCPD and MBPD derivatives are prepared using phenylboronic acid (PBA) to improve chromatographic behaviour and detection.
• Internal standard strategies: two sample preparations (parts A and B) use isotopically labelled standards (free and ester-bound) to monitor ester‑cleavage efficiency and to correct for artefacts.
• Result expression: results represent the sum of free plus ester‑bound analyte; the method does not distinguish free from bound forms.
• Scope and matrix considerations: applicable to refined and unrefined vegetable oils, solid fats, and - after validation - animal fats and used frying oils; milk and milk-derived fats excluded.
• Quality requirements: method includes provisions for spiking with surrogate standards, assessing cleavage efficiency, and recommended quality control/validation procedures. Annexes provide example chromatograms and interlaboratory validation data.

Practical applications and users

Who uses ISO 18363-2:2025:

• Food and feed analytical laboratories performing contaminant testing in oils and fats.
• Regulatory and enforcement agencies monitoring MCPDs and glycidol for food safety compliance.
• Refiners, edible‑oil processors and quality control teams validating mitigation processes that reduce MCPD/glycidol formation.
• Research laboratories studying formation pathways, mitigation strategies, and method development.

Typical applications:

• Routine surveillance and compliance testing for MCPD and glycidol residues in edible oils and fats.
• Process control and verification of refining steps intended to reduce formation of chloropropanediols and glycidyl esters.
• Comparative studies and method validation using isotopically labelled standards and interlaboratory data.

Related standards

• ISO 18363 series (other parts include ISO 18363‑1, ISO 18363‑3 and ISO 18363‑4) - provide alternative sample preparations and rapid methods for MCPD/glycidol determination.
• AOCS Official Methods (corresponding methods referenced in the introduction and annexes) for cross‑reference and validation data.

Keywords: ISO 18363-2:2025, MCPD, 2‑MCPD, 3‑MCPD, glycidol, GC/MS, slow alkaline transesterification, phenylboronic acid, MBPD, fats and oils analysis, food safety.