ISO 20948:2024

Overview - ISO 20948:2024 (aflatoxins in vegetable fats and oils)

ISO 20948:2024 specifies a validated analytical method for the determination of aflatoxins B1, B2, G1 and G2 in vegetable fats and oils. The method combines immunoaffinity column (IAC) clean-up with high-performance liquid chromatography (HPLC) and post‑column derivatization for fluorescence detection. It covers common edible oils including peanut, sesame, olive, corn, sunflower, rapeseed and coconut oil and defines limits of quantification and validation ranges for reliable regulatory and quality-control testing.

Key topics and technical requirements

• Scope and sample types: edible vegetable fats and oils (peanut, sesame, olive, corn, sunflower, rapeseed, coconut).
• Analytical principle: extraction with methanol–water (55:45 v/v), IAC clean‑up, elution and HPLC‑FLD analysis after post‑column derivatization.
• Instrumentation:
  • HPLC with fluorescence detector (HPLC‑FLD).
  • Post‑column derivatization options: photochemical reactor or electrochemical (Kobra) cell, used with specified mobile phases.
  • Immunoaffinity columns with antibodies specific for AFB1, AFB2, AFG1 and AFG2.
• Performance limits:
  • Limits of quantification (LOQ): AFB1 = 1 μg/kg, AFB2 = 0.25 μg/kg, AFG1 = 0.5 μg/kg, AFG2 = 0.25 μg/kg, sum of AFs = 1 μg/kg.
  • Validation ranges: AFB1: 1–20 μg/kg; total aflatoxins: 2–52 μg/kg.
• Reagents and quality control: requirements for solvent grades, PBS buffer, AF stock and working standards, and validated IAC recovery (≥80% for 5 ng AF applied).
• Safety: aflatoxins are hazardous (carcinogenic/toxic); precautions for handling and decontamination are specified.
• Documentation: analytical procedure, calibration, identification, calculation, precision and test report elements.

Practical applications and users

ISO 20948:2024 is intended for:

• Food testing laboratories performing routine aflatoxin screening and confirmatory analysis in edible oils.
• Regulatory agencies enforcing legal limits for aflatoxins and conducting market surveillance.
• Oil producers and quality‑control teams who need to verify raw material and finished‑product safety.
• Third‑party certification bodies and research labs conducting method validation or comparative studies.

Typical uses include compliance testing, supplier verification, export/import controls, and risk assessment for consumer protection.

Related standards and references

• ISO 3696 - Water for analytical laboratory use (normative reference for reagent water quality).
• The method is based on AOAC Official Method 2013.05 (as noted in the ISO introduction).
• Relevant laboratory safety and chemical handling guidance (e.g., IARC statements on aflatoxins) should be consulted when implementing the method.

Keywords: ISO 20948:2024, aflatoxins B1 B2 G1 G2, vegetable fats and oils, immunoaffinity column, HPLC-FLD, post-column derivatization, food safety, LOQ.