Overview
ISO 12228-1:2014 specifies a validated gas chromatographic method for the determination of individual and total sterols in animal and vegetable fats and oils. The standard defines the analytical principle, required reagents and apparatus, sample preparation (including saponification), isolation of the unsaponifiable fraction, chromatographic separation and quantification. Note: sterol analysis for olive and olive pomace oils is covered separately by ISO 12228-2.
Key topics and technical requirements
- Scope and definitions - clear definitions of composition of sterols (percentage profile) and total sterol content (mg/kg).
- Principle - saponify a measured test portion, isolate unsaponifiable matter on an aluminium oxide column, separate sterol fraction by thin‑layer chromatography (TLC), derivatize to trimethylsilyl ethers and quantify by gas chromatography (GC) using an internal standard.
- Reagents and internal standards - recommended use of cholestanol or betulin (1.0 mg/ml solution) as internal standard; advice on silylating reagents and solvent grades.
- Apparatus - requirements for GC (capillary column, flame ionization detector), TLC plates, aluminium oxide column, rotary evaporator and analytical balance.
- Procedure highlights - typical test portion (~250 mg), addition of 1.00 ml internal standard, reflux saponification (15 min), aluminium oxide column solid‑phase extraction, TLC development and GC measurement.
- Expression of results - identification and composition of individual sterols (normalized peak areas) and determination of total sterol content expressed in mg/kg.
- Performance data - includes precision information from interlaboratory trials (repeatability and reproducibility limits) and reporting requirements.
Applications and users
ISO 12228-1:2014 is used where reliable sterol profiling and quantification are required:
- Food testing laboratories performing sterol analysis in fats and oils.
- Quality control teams in edible oil and fat production (refining, blending).
- Regulatory and conformity assessment bodies verifying labeling, safety and purity.
- Research laboratories studying lipid composition, authentication and adulteration detection.
Practical benefits include standardized gas chromatographic sterol determination, comparable results across labs, and support for authenticity testing, compositional analysis and quality control of fats and oils.
Related standards
- ISO 12228-2 - Sterol determination for olive and olive pomace oils.
- ISO 661 - Preparation of test sample for animal and vegetable fats and oils.
- ISO 3696 - Water for analytical laboratory use.
- ISO 5555 - Recommended sampling methods for fats and oils.
Keywords: ISO 12228-1:2014, sterols, gas chromatographic method, animal and vegetable fats and oils, sterol composition, total sterol content, aluminium oxide column, thin-layer chromatography, cholestanol, betulin.