1 Scope
This standard specifies the determination method of migration of Bisphenol A in food contact materials and articles (polyvinyl choride, polycarbonate, epoxy resin and their finished products).
This standard is applicable to the liquid chromatography tandem mass spectrometry determination method for migration of Bisphenol A in food contact materials and articles (polyvinyl choride, polycarbonate, epoxy resin and their finished products).
2 Principle
Test the food simulants of food contact materials and articles (polyvinyl choride, polycarbonate, epoxy resin and their finished products) with liquid chromatography tandem mass spectrometry; inject the water-based, acidic and alcoholic food simulants directly while inject the oil-based food simulants after they are extracted with methanol solution; test the bisphenol A in the food simulants with liquid chromatography tandem mass spectrometry method and carry out quantitative determination by external standard peak area method.
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 method. As for the containers and transferring tools in the test, those made of plastic material shall not be used.
3.1 Reagents
3.1.1 Water-based, acidic, alcoholic and oil-based food simulants: the adopted reagents shall be in accordance with those specified in GB 5009.156.
3.1.2 N-hexane (C6H14): chromatographically pure.
3.1.3 Methanol (CH3OH): chromatographically pure.
3.2 Preparation of reagents
3.2.1 Water-based, acidic, alcoholic and oil-based food simulants: prepare according to GB 5009.156.
3.2.2 Methanol-water mixed solution (1+1): take 100mL of methanol (3.1.3) and 100mL of water, then mix them uniformly.
3.3 Standard products
Bisphenol A (C15H16O2): purity ≥99%.
3.4 Preparation of standard solutions
3.4.1 Bisphenol A standard stock solution (1,000mg/L): accurately weigh 10mg (to the nearest of 0.01mg) of Bisphenol A standard product and scale the volume to 10mL with methanol.
3.4.2 Bisphenol A standard intermediate solution (10mg/L): pipet 1.0mL of bisphenol A stock solution and scale the volume to 100mL with methanol.
3.5 Instruments and apparatus
3.5.1 Quadrupole liquid chromatography mass spectrometer: equipped with electrospray ionization source (ESI).
3.5.2 Vortex oscillator.
3.5.3 Microinjector: 10μL, 50μL and 1,000μL.
3.5.4 Analytical balance: with sensibility of 0.0001g and 0.01g.
3.5.5 Constant temperature humidity chamber.
3.5.6 0.2μm nylon membrane syringe filter.
4 Analysis Steps
4.1 Preparation of standard working solutions and specimen
4.1.1 Preparation of standard working solutions
4.1.1.1 Standard working solutions of water-based, acidic and alcoholic food simulants
Accurately pipet 0mL, 0.01mL, 0.05mL, 0.1mL, 0.5mL and 1.0mL of bisphenol A standard intermediate solution and pour them into 10mL-volumetric flasks, then scale the volumes with water to obtain the standard working solutions with the bisphenol A concentration as 0.00 mg/L, 0.01 mg/L, 0.05 mg/L, 0.1 mg/L, 0.5 mg/L and 1.0mg/L respectively. Prepare the bisphenol A standard working solution series with the same concentrations in the same way with water-based, acidic and alcoholic food simulants respectively.
4.1.1.2 Standard working solution of oil-based food simulants
Weigh 1g (to the nearest of 0.01g) of oil-based food simulants respectively and put them into seven test tubes with stopper, then transfer 0mL, 0.01mL, 0.03mL, 0.05mL, 0.07mL, 0.1mL and 0.3mL of bisphenol A standard intermediate solutions into test tubes with glass microinjector calibrated by gravimetric method to obtain the standard working solutions with the concentration of 0.00mg/kg, 0.10mg/kg, 0.30mg/kg, 0.50mg/kg, 0.70mg/kg, 1.0mg/kg and 3.0mg/kg respectively. Add 3mL of n-hexane into each test tube respectively, mix uniformly, then add 2mL of methanol-water mixed solution (1+1) and carry out vortex oscillation for 2min, after which, keep it still until layering. Pipet the water solution at the lower layer with glass injector, then filter it through the 0.2μm nylon membrane for determination.
4.1.2 Preparation of food simulant test solutions
4.1.2.1 General
Water-based, acidic, alcoholic and oil-based food simulants, which may include water-based and acidic foods, alcoholic foods and fatty foods, are adopted for the food simulation test of this standard. The required test solutions are obtained through migration test and may be preserved from light in 4℃ refrigerator for one week.
4.1.2.2 Migration test
Note: refer to GB 5009.156 for the actual food simulants and migration conditions.
4.1.2.2.1 Raw materials
Spread the raw material sample tightly in one layer on the paper of known size, calculate its surface area by regarding it as a rectangular solid (the thickness shall not be neglected), place the sample at 40℃ for 240h±0.5h, then carry out the migration test by the assumption that 10mL (or 10g) of food simulants are required for each 0.06dm2 of food contact area (or by weight).
4.1.2.2.2 Finished product
Select appropriate migration test conditions according to the geometric shape of the finished product; see relevant descriptions in GB/T23296.1 for detail.
4.1.2.3 Treatment of soak solution
4.1.2.3.1 Water-based, acidic and alcoholic food simulants
Transfer accurately 1ml of water-based, acidic and alcoholic food simulants obtained from the migration test, filter the simulants through a 0.2 μm filter membrane for determination; prepare two parallel samples.
4.1.2.3.2 Oil-based food simulants
Accurately weigh 1g±0.01g of the oil-based food simulants obtained from migration test, place it in the test tube, add 3mL of n-hexane into the test tube and mix uniformly; then add 2mL of methanol-water mixed solution (1+1) and carry out vortex oscillation for 2min, after which, keep it still for layering. Pipet the water solution at the lower layer with the injector, then filter it through the 0.2μm filter membrane for determination. Prepare two parallel samples
4.1.3 Preparation of blank test solution
Treat simulants which have not been in contact with food contact materials in the same way as described in 4.1.2.3.
1 Scope
2 Principle
3 Reagents and Materials
4 Analysis Steps
5 Expression of Analysis Results
6 Accuracy
7 Others
Annex A Reference Conditions of Mass Spectrometry
