Overview
EN 17958:2024 specifies a laboratory method for assessing food authenticity of honey by measuring compound-specific carbon isotope ratios. The standard describes the determination of the δ13C value (13C/12C) of mono- (fructose, glucose), di- and trisaccharides in honey using liquid chromatography coupled to isotope ratio mass spectrometry (LC‑IRMS). Measured sugar δ13C values are compared with guidance values for genuine honey to help detect adulteration with sugar syrups derived from starch-rich plants, sugar cane (C4) or sugar beet (C3). (Compliance assessment is explicitly not covered.)
Key topics and technical requirements
- Scope and principle: Separation of honey sugars by LC, online oxidation/combustion to CO2, and measurement of CO2 isotopologues (m/z 44, 45, 46) by IRMS to calculate δ13C.
- Sample preparation: Dilution with water, filtration and injection to LC; sequence design includes reference materials, blanks and QC samples.
- Instrumentation & interface:
- LC system and column suitable for mono/di/tri‑saccharide separation using water as mobile phase (polymeric styrene‑divinylbenzene Ca2+ columns are example).
- LC‑IRMS interface for chemical oxidation or combustion to CO2.
- IRMS with collectors for m/z 44/45/46; correction for m/z 45 contributions.
- Calibration & reference materials:
- Use at least two certified reference materials with δ13C values traceable to VPDB for two‑point linear normalization.
- Working gases (CO2, He) and high‑purity reagents required.
- Performance, precision & QA:
- Instrument vendor recommendations are followed for setup; Annexes provide interlaboratory conditions, example chromatograms and precision data.
- EA‑IRMS is cited as complementary; LC‑IRMS improves detection of some C3-derived adulterants and increases sensitivity to C4 sugars (EA‑IRMS can detect additions down to ~7%).
Applications and users
- Applications:
- Detection of honey adulteration with exogenous sugars (C3 and C4 origins).
- Compound‑specific isotopic profiling of honey sugars for quality control, forensic analysis and research.
- Who uses it:
- Official food control and regulatory laboratories.
- Accredited testing labs and proficiency schemes.
- Honey producers and quality assurance teams.
- Research institutions and standardization bodies developing authenticity protocols.
Related standards and references
- Complements bulk stable carbon isotope ratio analysis (EA‑IRMS) and methods harmonized by the International Honey Commission.
- Builds on prior LC‑IRMS applications (e.g., OIV LC‑IRMS methods for wine sugars).
- Traceability tied to VPDB and certified reference materials.
Keywords: EN 17958:2024, food authenticity, honey, δ13C, LC‑IRMS, isotope ratio mass spectrometry, sugar adulteration, stable carbon isotope ratio, VPDB.