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This standard replaces SN/T 2894-2011 Food Contact Materials for Export - Polymers - Determination of Methyl Methacrylate in Food Simulants - Gas Chromatography-Mass Spectrometry.
The following main changes have been made with respect to SN/T 2894-2011 (the previous edition):
——This standard is renamed as "National Food Safety Standard - Food Contact Materials and Articles - Determination of Migration of Methyl Methacrylate";
——The preparation of food simulant test solution is modified;
——The expression of analysis result is modified;
——The detection limit and the quantitation limit are modified.
National Food Safety Standard
Food Contact Materials and Articles
Determination of Migration of
Methyl Methacrylate
1 Scope
This standard specifies the gas chromatography-mass spectrometry for the determination of migration of methyl methacrylate in food contact materials and articles.
This standard is applicable to the determination of migration of methyl methacrylate in food contact materials and articles.
2 Principle
After extracting methyl methacrylate in water-based, acidic or alcoholic simulants with ethyl acetate and that in sunflower seed oil simulants with absolute ethanol, examine the extracting solution with gas chromatography-mass spectrometry and carry out quantitative determination with external standard 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.
3.1 Reagents
3.1.1 Sodium chloride (NaCl).
3.1.2 Anhydrous sodium sulfate (Na2SO4).
3.1.3 Ethyl acetate (C4H8O2): chromatographically pure.
3.1.4 Absolute ethanol (C2H5OH): chromatographically pure.
3.1.5 Water-based, acidic and alcoholic food simulants: the reagents adopted shall comply with the requirements of GB 31604.1.
3.1.6 Sunflower seed oil: the specification is detailed in Table B.1, Annex B.
3.2 Preparation of reagents
Water-based, acidic, alcoholic food simulants: prepare in accordance with GB 5009.156.
3.3 Standard product
Methyl methacrylate (MMA, C5H8O2, CAS No.: 80-62-6): with purity ≥99.0%.
3.4 Preparation of standard solutions
3.4.1 Methyl methacrylate standard stock solution (1,000 mg/L): accurately weigh 0.1 g (accurate to 0.1 mg) of methyl methacrylate, put it into a beaker, add in absolute ethanol to dissolve it, then transfer into a volumetric flask (100mL), scale the volume with absolute ethanol, and keep it sealed in dark place at 0℃~4℃.
3.4.2 Methyl methacrylate standard intermediate solution (200 mg/L): accurately transfer 10mL of methyl methacrylate standard stock solution into a volumetric flask (50mL), and scale the volume with absolute ethanol, preserve it in the same way as specified in 3.4.1.
3.4.3 Water-based, acidic or alcoholic food simulants standard working solution: transfer 250 μL, 500 μL, 2,500 μL, 5,000 μL and 10,000 μL of methyl methacrylate standard intermediate solution into a volumetric flask (100mL) respectively, dilute into methyl methacrylate water-based, acidic, alcoholic standard working solution with the concentration of 0.5 mg/L, 1 mg/L, 5 mg/L, 10 mg/L and 20 mg/L with water-based, acidic or alcoholic simulants respectively, and then extract according to 5.2.1.
3.4.4 Sunflower seed oil simulants standard working solution: weigh 2 g (accurate to 0.1 mg) of sunflower seed oil simulants respectively, put into six centrifuge tubes with stopper (10mL), transfer 0 μL, 7 μL, 10 μL, 20 μL, 50 μL and 100 μL of methyl methacrylate standard intermediate solution into the centrifuge tubes with adjustable pipette respectively, and mix uniformly with vortex oscillator. The concentrations of sunflower seed oil simulants standard working solution are: 0.0 mg/kg, 0.7 mg/kg, 1mg/kg, 2 mg/kg, 5 mg/kg and 10 mg/kg. Carry out extraction according to 5.2.2.
4 Instruments and Apparatus
4.1 Gas chromatograph: equipped with mass spectrometry detector.
4.2 Vortex oscillator.
4.3 Electronic balance: with sensibility of 0.1mg.
4.4 Centrifuger: 4,000r/min.
4.5 Volumetric flask: 50mL, 100mL and 1,000mL.
4.6 Organic filter membrane: 0.45 μm.
4.7 Pipette: 2mL, 5mL and 10mL.
4.8 Centrifuge tube with stopper: 10mL.
4.9 Adjustable pipette (1 μL~20 μL, 20 μL~100 μL and 100 μL~5,000 μL).
5 Analysis Steps
5.1 Sample migration test
Carry out migration test in accordance with the requirements of GB 5009.156 and GB 31604.1 for the sample to obtain the food simulant test solution; if the obtained food simulant test solution fails to be used for the next test immediately, it shall be kept in dark place in a refrigerator of 0℃~4℃.
The obtained food simulant test solution shall be cooled or recovered to ambient temperature for the next step of the test.
5.2 Preparation of test solution
5.2.1 Preparation of water-based, acidic or alcoholic food simulant test solution
Transfer 2.0mL of water-based, acidic or alcoholic food simulants obtained from migration test into a centrifuge tube with stopper (10mL), and add 0.5g of sodium chloride and 2mL of ethyl acetate into the centrifuge tube respectively; keep it still for 2min after extraction through vortex (1,500r/min) for 1.5 min, transfer the supernatant, dry it with anhydrous sodium sulfate, and filter it through 0.45 μm filter membrane for the determination of gas chromatography-mass spectrometry.
5.2.2 Preparation of sunflower seed oil simulant test solution
Weigh 2g (accurate to 0.1mg) of sunflower seed oil food simulants obtained from migration test, put it into a centrifuge tube with stopper (10mL), and add 2mL of absolute ethanol into the centrifuge tube; keep it still for 2min after extraction through vortex (1,500r/min) for 1 min, carry out high speed centrifugation (4,000 r/min) with centrifuger for 5min, transfer the supernatant immediately, and filter it through 0.45 μm filter membrane for the determination of gas chromatography-mass spectrometry.
Foreword i
1 Scope
2 Principle
3 Reagents and Materials
4 Instruments and Apparatus
5 Analysis Steps
6 Expression of Analysis Results
7 Accuracy
8 Others
Annex A Selected Ion Monitoring for Gas Chromatography-Mass Spectrometry of Methyl Methacrylate (MMA) Standard Products
Annex B Specification of Sunflower Seed Oil
