This standard specifies the determination methods of Vitamins A, E and D in foods.
Method I of this standard is applicable to the determination of Vitamins A and E in foods.
Method II of this standard is applicable to the determination of Vitamins E in foods such as edible oil, nuts, beans and chili powder.
Method III of the standard is applicable to the determination of Vitamins D2 and D3 in foods.
Method IV of this standard is applicable to the determination of Vitamins D2 and D3 in formula foods.
Method I Determination of Vitamins A and E in Foods Reversed-phase High Performance Liquid Chromatography
2 Principle
After subjecting to saponification (subjecting to enzymolysis with amylase first for starch-containing specimen), extraction, purification and concentration, Vitamins A and E in the specimen are separated by C30 or PFP reversed-phase liquid chromatographic column, detected with ultraviolet detector or fluorescence detector and quantitated by external standard method.
3 Reagents and Materials
Unless otherwise specified, analytically-pure reagents and Grade I water (defined in GB/T 6682) are adopted for the purposes of this method.
3.1 Reagents
3.1.1 Absolute ethanol (C2H5OH): without aldehyde substance after inspection, see A.1 for inspection method.
3.1.2 Ascorbic acid (C6H8O6).
3.1.3 Potassium hydroxide (KOH).
3.1.4 Ethyl ether [(CH3CH2)2O]: without peroxide after inspection, see A.2 for inspection method.
3.1.5 Petroleum ether (C5H12O2): with boiling range of 30℃~60℃.
3.1.6 Anhydrous sodium sulfate (Na2SO4).
3.1.7 pH test paper (at the pH range of 1~14).
3.1.8 Methanol (CH3OH): chromatographically pure.
3.1.9 Amylase: activity unit≥100U/mg.
3.1.10 2,6-Di-tert-butyl-4-methylphenol (C15H24O): referred to as BHT.
3.2 Reagent preparation
3.2.1 Potassium hydroxide solution (50g/100g): weigh 50g of potassium hydroxide, dissolve it with 50mL of water, after cooling, store it in a polyethylene bottle.
3.2.2 Petroleum ether - ethyl ether solution (1+1): measure 200mL of petroleum ether and add into 200mL of ethyl ether, mix them well.
Contents Foreword i 1 Scope 2 Principle 3 Reagents and Materials 4 Apparatuses 5 Analysis Procedures 6 Expression of Analysis Results 7 Accuracy 8 Others 9 Principle 10 Reagents and Materials 11 Apparatuses 12 Analysis Procedures 13 Expression of Analysis Results 14 Accuracy 15 Others 16 Principle 17 Reagents and Materials 18 Apparatuses 19 Analysis Procedures 20 Expression of Analysis Results 21 Accuracy 22 Others 23 Principle 24 Reagents and Materials 25 Apparatuses 26 Analysis Procedures 27 Expression of Analysis Results 28 Accuracy 29 Others Appendix A Appendix B Calibration Method for Concentrations of Vitamins A, D and E Standard Solutions Appendix C Chromatogram