1 Scope
This standard specifies the gas chromatography method for testing vegetable fat in milk and milk products.
This standard is applicable to the qualitative inspection of vegetable fat in milk and milk products.
2 Normative reference
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document applies.
GB/T 6682 Water for analytical laboratory use — Specification and test methods (GB/T 6682-1992, neq ISO 3696:1987)
3 Principle
Specimens were saponified by potassium hydroxide in ethanol solution, fats were extracted by ether and petroleum ether, solvents were removed by distillation or evaporation, free sterols were extracted by n-hexane, and analyzed by gas chromatography. If, the sample contains β-sitosterol, it is determined that it contains vegetable fat.
4 Reagents and materials
All reagents are analytically pure if the specifications are not indicated. If not indicated, the experimental water shall meet the provisions of GB/T 6682.
Foreword i
1 Scope
2 Normative reference
3 Principle
4 Reagents and materials
5 Apparatus and instruments
6 Test sample preparation
7 Analytical procedures
8 Expression of results
9 Sensitivity
Annex A (Informative) Typical gas chromatogram of cholesterol and β-sitosterol
