Overview - ISO 18465:2017 (cereulide quantification by LC‑MS/MS)
ISO 18465:2017 specifies a standardized, quantitative LC‑MS/MS method for measuring the emetic toxin cereulide (produced by Bacillus cereus) in food. The method uses HPLC or UHPLC coupled to a tandem mass spectrometer (LC‑MS/MS) with electrospray ionization (positive mode) and multiple reaction monitoring (MRM). It is applicable to products intended for human consumption and expresses results as µg cereulide/kg product.
Key technical topics and requirements
- Analyte & scope: Quantitative determination of cereulide (cyclic dodecadepsipeptide) in food matrices susceptible to emetic toxin contamination.
- Extraction & sample preparation:
- Representative homogenization and a defined extraction (example: 2.5 g sample with internal standard, extraction into acetonitrile).
- Optional clean‑up (e.g., heptane partitioning) to remove fatty interferences when required.
- Internal standard and calibration:
- Use of a labelled internal standard (C‑cereulide) and preparation of calibration standards in acetonitrile/methanol to generate a calibration curve.
- Chromatography & mass spectrometry:
- Use of C18 reversed‑phase LC columns (HPLC or UHPLC) with specified mobile phases (ammonium formate/formic acid in water and formic acid in acetonitrile).
- MS operated in positive ESI mode with MRM transitions and instrument tuning as specified in the standard.
- Quality assurance & performance:
- Requirements for quality controls, precision (repeatability and reproducibility), and reporting.
- Inclusion of interlaboratory study results and guidance on method performance metrics.
- Reagents & equipment: Specifies reagent grades (LC‑MS grade solvents, formic acid), centrifuges, filters, autosampler vials, and freezer storage for standards.
Practical applications and users
This standard is designed for laboratories and organisations involved in food safety testing, including:
- Public health and regulatory laboratories performing surveillance and outbreak investigation.
- Commercial food testing laboratories offering routine analysis for manufacturers and retailers.
- Food manufacturers and quality assurance teams monitoring raw materials and finished products (e.g., rice, pasta, canned and ready‑to‑eat foods).
- Research laboratories studying cereulide occurrence, variants, and toxin stability.
Using ISO 18465:2017 helps ensure reliable, comparable quantitative data for risk assessment, product release decisions, and foodborne outbreak investigations.
Related standards
- ISO 3696 - Water for analytical laboratory use (reagent water quality).
- ISO 1042 - Laboratory glassware - One‑mark volumetric flasks.
- The standard was prepared in collaboration with CEN/TC 275 and complements other ISO methods for microbiology and chemical analysis of the food chain.
Keywords: ISO 18465:2017, cereulide, emetic toxin, LC‑MS/MS, HPLC, UHPLC, food safety, quantitative determination, Bacillus cereus, MRM.