ISO 18363-1:2015

Overview

ISO 18363-1:2015 specifies a validated GC/MS method for the indirect determination of 3‑MCPD esters (bound 3‑MCPD) and glycidyl esters (bound glycidol) in solid and liquid animal and vegetable fats and oils. Published by ISO in 2015, the method uses a fast alkaline transesterification (alcoholysis) at room temperature, followed by derivatization with phenylboronic acid (PBA) and GC/MS analysis. Milk and milk‑derived fats are explicitly excluded.

This part is equivalent to DGF C‑VI 18 and identical to AOCS Official Method Cd 29c‑13.

Key topics and requirements

• Analytes covered: bound 3‑MCPD (reported as 3‑MCPD) and indirect/differential measurement of bound glycidol (glycidyl esters).
• Principle:
  • A fast alkaline catalysed ester cleavage releases 3‑MCPD and glycidol from esters.
  • Two parallel assays (A and B) are used:
    • Assay A converts glycidol into induced 3‑MCPD (using an acidified chloride solution), so A measures the sum of bound 3‑MCPD + bound glycidol as 3‑MCPD.
    • Assay B uses a chloride‑free stop solution to prevent glycidol → 3‑MCPD conversion and measures genuine bound 3‑MCPD.
    • Bound glycidol is determined from the difference (A − B) using an experimentally determined conversion ratio.
• Sample types and scope: applicable to refined and non‑refined vegetable oils/fats and, with prior validation, to animal fats and used frying oils. Milk fats/milk products are excluded.
• Sample workflow elements: spiking with surrogate standard, ester cleavage, matrix clean‑up, derivatization with PBA, GC/MS measurement, expression of results in mg/kg.
• Limitations:
  • Results include any free analytes present; the standard does not separate free vs. bound forms.
  • Accurate glycidol quantification assumes no other substances form 3‑MCPD from chloride at room temperature.
• Quality and reporting: standard includes precision data (interlaboratory, repeatability, reproducibility) and specifies required test‑report content.

Applications and users

• Routine and regulatory testing of edible oils, fats, and frying oils for process‑induced contaminants.
• Food testing laboratories, quality control teams in edible‑oil production, regulatory bodies, and research labs evaluating MCPD and glycidol levels.
• Useful for suppliers verifying compliance with food‑safety limits and for risk assessment of process contaminants in lipid matrices.

Related standards

• ISO 18363 series (other parts under preparation) covering:
  • Part 2: slow alkaline transesterification (2‑MCPD, 3‑MCPD, glycidol)
  • Part 3: acid transesterification (2‑MCPD, 3‑MCPD, glycidol)
• Equivalent/related methods: DGF C‑VI 18; AOCS Official Methods Cd 29a/29b/29c series.

Keywords: ISO 18363‑1:2015, 3‑MCPD esters, glycidol, glycidyl esters, MCPD, GC/MS, phenylboronic acid, alkaline transesterification, fats and oils testing.