Overview
EN 18054:2025 - "Food authenticity: Determination of C and/or N isotope ratios in food by Elemental Analyser - Isotope Ratio Mass Spectrometry (EA-IRMS)" is a CEN European standard that specifies instrumental procedures for measuring carbon and nitrogen stable isotope ratios in food materials. The method yields isotope delta values expressed as δ13C and/or δ15N relative to international measurement standards. The standard covers EA‑IRMS instrumentation, measurement principle, sequence design, instrumental tests, corrections and data processing. Sample preparation and interpretation of isotope delta results are explicitly excluded.
Key topics and technical requirements
- Scope and principle: Measurement of C and N isotope ratios by EA‑IRMS; sample gas produced in an elemental analyser (CO2 for C, N2 for N) is introduced to the mass spectrometer.
- Normalization and traceability: Results must be reported on recognized international scales - VPDB for carbon and Air‑N2 for nitrogen - using two or more reference materials for scale normalization.
- Instrumental setup and tests: Requirements and checks for sample introduction, flash‑combustion/reduction, gas separation and mass spectrometer operation.
- Sequence design and quality control: Guidance on sequence composition (standards, blanks, samples), and instrumental tests including backgrounds, working‑gas stability, linearity, and magnet “jump” calibration for dual isotope measurements.
- Data processing and corrections: Procedures for raw data evaluation, rejection criteria for runs/samples/sequences, corrections to initial isotope delta values, and documentation of data to record.
- Performance metrics: Sections on precision (repeatability, reproducibility) and uncertainty, plus annexes with inter‑laboratory validation and a worked data processing example.
Applications and users
EN 18054:2025 is intended for laboratories and organizations performing isotope analysis for food authenticity and forensic investigations. Typical users include:
- Accredited food testing laboratories implementing EA‑IRMS methods.
- Regulatory and enforcement agencies verifying origin, adulteration or labeling claims.
- Food manufacturers and quality assurance teams conducting authenticity screening (e.g., detection of sugar adulteration in honey, feed‑related isotopic signatures in meat).
- Research institutions studying isotopic markers in food chains.
Note: The standard produces calibrated δ13C / δ15N values; interpretation (e.g., origin attribution, adulteration thresholds) requires separate domain expertise and reference databases.
Related standards and references
- Uses international reference scales VPDB (carbon) and Air‑N2 (nitrogen) for traceability.
- EN 18054:2025 complements other analytical standards and laboratory accreditation requirements for isotope ratio mass spectrometry and food authenticity testing.