This standard specifies the method for determination of fatty acids in foods for infants and young children and milk products.
This standard is applicable to the determination of fatty acids in foods for infants and young children and milk products, and the second method is not applicable to the determination of embedded fatty acids.
2 Normative References
The documents referenced in this standard are indispensable for the application of this standard. For dated references, only the dated edition is applicable to this standard. For undated references, the latest edition (including all amendments) is applicable to this standard.
First Method: Acetyl Chloride-Methanol Methyl Esterification Method
3 Principle
Hydrochloric acid-methanol obtained through acetyl chloride and methanol reaction makes fat and free fatty acid in sample methyl esterification; extract with methylbenzene, and then separate and detect through gas chromatograph, and quantify with external standard method.
4 Reagents and Materials
Unless otherwise specified, all reagents used in this method shall be analytical pure, and the water shall be the Grade I water as specified in GB/T 6682.
4.1 Anhydrous sodium carbonate.
4.2 Methylbenzene: chromatographic pure.
4.3 Acetyl chloride.
4.4 Acetyl chloride methanol solution (volume fraction 10%): measure 40mL methanol into 100mL dry beaker, accurately pipet 5.0mL acetyl chloride (4.3) to slowly add drop by drop, continuously stir, cool, and then transfer and scale the volume to 50mL dry volumetric flask. Prepare immediately before use.
