Overview
EN ISO 18465:2017 / ISO 18465:2017 specifies a validated, chemical analytical method for the quantitative determination of the emetic toxin cereulide in foods using liquid chromatography coupled to tandem mass spectrometry (LC‑MS/MS). The standard covers extraction, use of isotopically labelled internal standard (C‑13‑cereulide), chromatographic separation (HPLC or UHPLC) and tandem MS detection (ESI positive mode). Results are reported as micrograms of cereulide per kilogram of product (µg/kg). The method applies to foods and products intended for human consumption.
Key topics and requirements
- Scope: Quantitative analysis of cereulide (the cyclic emetic toxin produced by certain Bacillus cereus strains) in food matrices.
- Sample extraction: Cereulide is extracted from the food matrix by shaking with acetonitrile.
- Internal standard: Use of C‑13 labelled cereulide as the internal standard for accurate quantitation.
- Chromatography: HPLC or UHPLC separation prior to MS/MS.
- Mass spectrometry: Tandem MS with electrospray ionization (ESI) in positive mode; multiple reaction monitoring (MRM) transitions are defined for specificity.
- Reagents and solutions: LC‑MS grade acetonitrile and methanol, formic acid, ammonium formate, and prepared stock/standard solutions (examples and concentrations are specified in the standard).
- Performance and quality: Procedures for calibration, quality controls, precision (repeatability and reproducibility) and interlaboratory study results are included to support method reliability.
- Reporting: Concentrations expressed as µg cereulide/kg product.
Applications and users
- Food testing laboratories performing targeted chemical analysis for food safety and contamination surveillance.
- Public health and outbreak investigation teams needing specific quantitation of cereulide in implicated food items.
- Regulatory bodies and inspection agencies validating compliance with safety assessments.
- Food manufacturers and quality assurance teams monitoring finished products (especially starch‑rich foods historically associated with cereulide, e.g., rice and pasta dishes).
- Research laboratories studying Bacillus cereus toxins, cereulide variants and their occurrence in the food chain.
Practical value
- Provides a specific, reproducible LC‑MS/MS protocol for cereulide quantification, improving comparability across labs.
- Supports robust food safety investigations by detecting a heat‑ and acid‑stable toxin that may persist even when B. cereus is no longer culturable.
- Enables traceable results using isotopically labelled internal standards and defined quality control practices.
Related standards
- ISO 3696 - Water for analytical laboratory use (referenced for reagent quality).
- ISO 1042 - Laboratory glassware - Volumetric flasks (referenced for solution preparation).
Keywords: EN ISO 18465:2017, ISO 18465:2017, cereulide, emetic toxin, LC‑MS/MS, HPLC, UHPLC, food microbiology, food safety testing, Bacillus cereus.