1 Scope
This standard specifies the determination methods of antioxidant, namely butylated hydroxyl anisole (BHA), dibutylated hydroxyl toluene (BHT) and tertiary butyl hydroquinone (TBHQ) in foods with the help of gas chromatography.
This standard is applicable to the determination of BHA, BHT and TBHQ in foods.
The detection limits of the methods in this standard are: BHA 2mg/kg, BHT 2mg/kg and TBHQ 5mg/kg.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, subsequent amendments (excluding corrigendum content) to, or revisions of, any of these publications do not apply. However, parties that enter into an agreement according to this standard are encouraged to study whether the latest edition of these documents can be used. For undated references, the latest editions of the normative documents are applicable to this standard.
GB/T 6682-2008 Water for Analytical Laboratory Use-Specification and Test Methods (ISO 3696: 1987, MOD)
3 Principle
After extracted by organic solvent and purified by gel permeation chromatography purification system (GPC), the antioxidant in the samples shall be detected by the gas chromatography-flame ionization detection. The retention time method is used for qualitative study; the external standard method is used for quantitative study.
4 Reagents and Materials
Unless otherwise stated, all of the adopted reagents shall be analytical pure. And the water used in the test shall be of second-class quality (specified in GB/T 6682-2008).
4.1 Cyclohexane
4.2 Ethyl acetate
4.3 Petroleum ether: boiling range 30℃~60℃ (double distillated)
4.4 Acetonitrile
4.5 Acetone
4.6 Standard BHA: purity≥99.0%,-18℃ (stored freezingly)
4.7 Standard BHT: purity≥99.3%,-18℃(stored freezingly)
4.8 Standard TBHQ: purity≥99.0%,-18℃(stored freezingly)
4.9 Standard stock solution of BHA, BHT and TBHQ: Respectively weigh 50mg(to an accuracy of 0.1mg) standard BHA, BHT and TBHQ. Scale the volume to 50ml with the solution containing ethyl acetate and cyclohexane (the volume ratio is 1:1) so as to produce a stock solution with a concentration of 1mg/ml.
