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This standard replaces GB/T 23296.18-2009 Food Contact Materials - Polymer - Determination of Monoethylene Glycol and Diethylene Glycol in Food Simulants - Gas Chromatography.
The following changes have been made with respect to GB/T 23296.18-2009 (the previous edition):
——this standard is renamed as National Food Safety Standard - Food Contact Materials and Articles - Determination of Migration of Ethylene Glycol and Diethylene Glycol;
——test types of food simulants are added.
National Food Safety Standard
Food Contact Materials and Articles
Determination of Migration of Ethylene Glycol and Diethylene Glycol
1 Scope
This standard specifies thedetermination method of gas chromatography for the migration of ethylene glycol and diethylene glycol in food contact materials and articles.
This standard is applicable to the determination of migration of ethylene glycol and diethylene glycol in food contact materials and articles.
2 Principle
Separate the ethylene glycol and diethylene glycol in food container and packaging material simulants by capillary gas chromatographic column and detect with hydrogen flame ionization detector. For the water-based, acidic or alcoholic food simulant, directly inject the sample; for the oil-based food simulant, inject the sample after water extraction for analysis; carry out the quantitative determination by internal standard method with 1,4-butanediol as the internal standard substance.
3 Reagents and Materials
Unless otherwise specified, analytically-pure reagents and Class-I water (defined in GB/T 6682) are adopted for the purpose of this standard. Containers and transfer appliances in test shall not be made of plastic materials.
3.1 Reagents
3.1.1 Glacial acetic acid (C2H4O2).
3.1.2 Absolute ethanol (C2H6O).
3.1.3 Methanol (CH4O).
3.1.4 Heptane (C7H16).
3.1.5 Reagents required for preparation of water-based, acidic, alcoholic and oil-based food simulants: in accordance with the requirements of GB 31604.1.
3.2 Preparation of reagents
Water-based, acidic, alcoholic and oil-based food simulants: prepare according to GB 5009.156.
3.3 Standard products
3.3.1 Ethylene glycol (C2H6O2, CAS No.: 107-21-1).
3.3.2 Diethylene glycol (C4H10O3, CAS No.: 111-46-6).
3.3.3 1,4-butanediol(C4H10O2, CAS No.: 110-63-4).
3.4 Preparation of standard solutions
3.4.1 Ethylene glycol (7,500 mg/L) and diethylene glycol (7,500 mg/L) stock solutions: accurately weigh 0.75 g (accurate to 0.1 mg) ethylene glycol and diethylene glycol and put into two beakers respectively, dissolve with methanol, transfer to 100mL volumetric flasks respectively, scale the volume with methanol. Seal and keep such solution in dark place at 0℃~4℃ for 1 month.
3.4.2 1,4-butanediol (10,000 mg/L) stock solution: accurately weigh 1 g (accurate to 0.1 mg) 1,4-butanediol and put into a beaker, dissolve with methanol, transfer to a 100mL volumetric flask and scale the volume with methanol. Keep such solution in dark place at 0℃~4℃ for 1 month.
3.4.3 1,4-butanediol (800 mg/L) solution: accurately pipet 2 mL 1,4-butanediol (10,000 mg/L) stock solution and put into a 25 mL volumetric flask and scale the volume with methanol. Keep such solution in dark place at 0℃~4℃, which shall be prepared immediately before use.
3.4.4 Standard intermediate solution: accurately pipet 2 mL 1,4-butanediol (10,000 mg/L) stock solution and put into six 25 mL volumetric flasks, add 0.0 mL, 0.5 mL, 1.0 mL, 2.5 mL, 5.0 mL and 10.0 mL ethylene glycol and diethylene glycol stock solutions respectively, scale the volume with methanol and obtain the standard intermediate solution with the ethylene glycol/diethylene glycol concentrations of 0.0 mg/L, 150.0 mg/L, 300.0 mg/L, 750.0 mg/L, 1,500 mg/L and 3,000 mg/L respectively and with the 1,4-butanediol concentration of 800 mg/L. Keep such solution in dark place at 0℃~4℃, which shall be prepared immediately before use.
4 Instruments and Apparatus
4.1 Gas chromatograph: equipped with flame ionization detector and automatic data analysis software.
4.2 Analytical balance: with sensibility of 0.0001 g, 0.01 g or 0.1 g.
4.3 Separating funnel: 250 mL, which is equipped with PTFE or glass bottle stopper and shall be dried before use.
4.4 Volumetric flask: 25 mL, 50 mL and 100 mL.
4.5 Graduated pipette: 1 mL and 2 mL.
4.6 Glass injector: 50 mL.
4.7 Filter: 0.22 μm organic phase filter membrane, pin-type.
5 Analysis Steps
5.1 Preparation of standard working solutions and specimens
5.1.1 Preparation of standard working solutions
5.1.1.1 Standard working solution of water-based, acidic or alcoholic food simulant
Accurately pipet 1 mL standard intermediate solutions with different concentrations into six 50 mL volumetric flasks, scale the volume with water and obtain the standard working solution with the concentrations of ethylene glycol and diethylene glycol in water of 0.0 mg/L, 3.0 mg/L, 6.0 mg/L, 15.0 mg/L, 30.0 mg/L and 60.0 mg/L respectively. In the same way, prepare ethylene glycol and diethylene glycol standard working solutions with the same concentration series with corresponding water-based, acidic or alcoholic food simulant respectively.
Foreword i
1 Scope
2 Principle
3 Reagents and Materials
4 Instruments and Apparatus
5 Analysis Steps
6 Expression of Analysis Results
7 Repeatability
