Overview
EN ISO 15774:2017 - "Animal and vegetable fats and oils - Determination of cadmium content by direct graphite furnace atomic absorption spectrometry" - is a CEN-adopted ISO method for measuring trace cadmium (Cd) at micrograms per kilogram in crude and refined edible oils and fats. Published in 2017, this method supersedes EN ISO 15774:2001. Milk and milk‑derived fats are excluded from the scope.
Key topics and technical requirements
- Analytical principle: direct graphite furnace atomic absorption spectrometry (GF‑AAS). Samples are incinerated/atomized in a pyrolytic graphite tube and Cd is measured at 228.8 nm.
- Matrix modification: palladium is used as a matrix modifier to prevent Cd loss during thermal pretreatment (0.1% Pd solution prepared from PdCl2).
- Calibration and standards: use organometallic cadmium standard (example given) to prepare a 10 mg/kg stock and working standards (2.5, 5.0 and 10.0 µg/kg) in refined vegetable oil.
- Reagents & gases: analytical‑grade water (ISO 3696 grade 1), cyclohexane, hydrochloric acid, PdCl2, and argon (≥99.99%) for the furnace.
- Apparatus: GF‑AAS with peak‑area/autocalibrate modes, deuterium background or Zeeman correction; uncoated graphite tubes with a pyrolytic platform; optional autosampler (sample cup heating at 60 °C ±10 °C).
- Sample preparation: oils and standards are equilibrated at ~60 °C; high‑melting fats (mp ≥ 40 °C) are diluted 1:1 (mass/mass) with blank oil; autosampler injection volumes specified (15 µl heated, 20 µl when solvent‑diluted).
- Quality & performance: document includes precision data (repeatability, reproducibility) from interlaboratory tests and prescribes reporting elements for test reports.
Applications
- Routine food safety testing for cadmium contamination in edible oils and fats.
- Quality control in edible oil refining, seed oil processing, biodiesel feedstock assessment (when relevant to food chain).
- Regulatory compliance testing for maximum Cd limits set by food safety authorities.
- Method validation and interlaboratory comparison studies for trace metal analysis in lipid matrices.
Who uses this standard
- Accredited analytical and food testing laboratories
- Oil & fat producers and refiners (quality assurance teams)
- Regulatory agencies and public health laboratories
- Method developers and instrument vendors supplying GF‑AAS solutions
Related standards
- ISO 3696 - Water for analytical laboratory use (normative reference).
- EN ISO 15774:2001 - previous edition (now superseded).
Keywords: EN ISO 15774:2017, cadmium determination, graphite furnace atomic absorption spectrometry, GF‑AAS, edible oils, fats, trace metals, palladium matrix modifier, food safety.
