GB 31604.61-2025 National food safety standard - Food contact materials and products - Determination of migration of 2,2,4,4- tetramethyl -1,3- cyclobutanediol English, Anglais, Englisch, Inglés, えいご
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National Standard of the People's Republic of China
GB 31604.61-2025
National food safety standard - Food contact materials and products - Determination of migration of 2,2,4,4- tetramethyl -1,3- cyclobutanediol
Issue date: 2025-09-02 Implementation date: 2026-03-02
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the National Health Commission of the People’s Republic of China
Contents
Foreword
1 Scope
2 Principle
3 Reagents and Materials
4 Instruments and Equipment
5 Analytical Procedure
6 Expression of Analytical Results
7 Precision
8 Others
National food safety standard - Food contact materials and products - Determination of migration of 2,2,4,4- tetramethyl -1,3- cyclobutanediol
1 Scope
This standard specifies the method for determining the migration of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in food contact materials and articles.
This standard applies to the determination of 2,2,4,4-tetramethyl-1,3-cyclobutanediol migration in plastic and coated food contact materials and articles.
2 Principle
After migration testing of food contact materials and articles using food simulants or substitute solvents, the following procedures apply: - For water, acidic, and ethanol-containing food simulant extracts: Dilute with methanol before determination. - For lipid-containing food simulant extracts: Extract with methanol before determination. - For chemical substitute solvents (95% ethanol and iso-octane) extracts: Determine directly by instrumentation. Test solutions are separated via gas chromatography columns and detected by hydrogen flame ionization detectors. Retention times provide qualitative analysis, while peak areas enable quantitative determination using external standard methods.
3 Reagents and Materials
Unless otherwise specified, reagents used in this method are analytical grade. Water complies with Grade 1 water as defined by GB/T 6682.
3.1 Reagents
3.1.1 Acetic acid (C₂H₄O₂).
3.1.2 Ethanol (C₂H₆O).
3.1.3 Isooctane (C₈H₁₈): Chromatographic grade.
3.1.4 Olive oil: Must meet the requirements of Appendix A in GB 5009.156.
3.1.5 Methanol (CH₄O): Chromatographic grade.
3.1.6 Methyl tert-butyl ether (C₅H₁₂O): Chromatographic grade.
3.2 Reagent Preparation
4% (v/v) acetic acid solution, 10% (v/v) ethanol solution, 20% (v/v) ethanol solution, 50% (v/v) ethanol solution, and 95% (v/v) ethanol solution: Prepare according to GB 5009.156. Food simulants used shall comply with GB 31604.1 and relevant product standards.
3.3 Reference Materials
2,2,4,4-Tetramethyl-1,3-cyclobutanediol (C₈H₁₆O₂, CAS No.: 3010-96-6): Purity ≥99%, or a reference material/standard sample certified by a national authority and granted a Certificate of Analysis.
3.4 Preparation of Standard Solutions
3.4.1 Standard Stock Solution (1000 mg/L)
Accurately weigh 25 mg (to the nearest 0.1 mg) 2,2,4,4-Tetramethyl-1,3-cyclobutanediol standard material, dissolve in methanol, transfer to a 25 mL brown volumetric flask, dilute to the mark with methanol, Shake thoroughly, allow to settle, and store in a brown glass bottle. This solution should be stored sealed in a refrigerator at 0°C to 4°C and is valid for 6 months.
3.4.2 Standard Intermediate Solution
3.4.2. 1 Standard Intermediate Solution I (100 mg/L): Accurately transfer 1.00 mL of the standard reserve solution into a 10 mL brown volumetric flask. Dilute precisely to the mark with methanol, shake thoroughly, allow to settle, and store in a brown glass bottle. This solution should be stored sealed in a refrigerator at 0°C to 4°C and is valid for 3 months.
3.4.2.2 Standard Intermediate Solution II: Accurately transfer 0.10 mL, 0.20 mL, 0.40 mL, 1.00 mL, and 2.00 mL of the standard stock solution into separate 10 mL brown volumetric flasks. Dilute to the mark with methyl tert-butyl ether (MTBE), Shake thoroughly and allow to settle. This yields standard intermediate solutions with mass concentrations of 10 mg/L, 20 mg/L, 40 mg/L, 100 mg/L, and 200 mg/L, respectively. Store in amber glass bottles. Seal and store at 0°C to 4°C in a refrigerator. Shelf life is 3 months.
3.4.3 Standard Working Solutions
3.4.3.1 Standard Working Solution A (for water-based food simulants): Accurately transfer 50 μL, 100 μL, 200 μL, 300 μL, and 500 μL of the 100 mg/L standard intermediate solution I into five 10 mL volumetric flasks. Add 2.0 mL of the corresponding blank food simulant (water, 4% acetic acid, 10% ethanol, 20% ethanol, 50% ethanol), then dilute with methanol to the mark. Shake thoroughly and let stand to obtain standard working solutions with concentrations of 0.50 mg/L, 1.0 mg/L, 2.0 mg/L, 3.0 mg/L, and 5.0 mg/L. Prepare fresh before use.
3.4.3.2 Standard Working Solution B (Applicable to Chemical Substitute Solvents 95% Ethanol and Isooctane) : Accurately transfer 50 μL, 100 μL, 200 μL, 500 μL, and 1000 μL of the 100 mg/L standard intermediate solution II into five 10 mL volumetric flasks. Dilute to the mark with the corresponding chemical substitute solvent (95% ethanol or iso-octane). Shake thoroughly and allow to stand to obtain standard working solutions with concentrations of 0.50 mg/L, 1.0 mg/L, 2.0 mg/L, 5.0 mg/L, and 10 mg/L. Prepare fresh for immediate use.
3.4.3.3 Standard Working Solution C (for lipid-containing food simulants): Accurately weigh 2.0 g (to 0.001 g precision) of olive oil into five stoppered centrifuge tubes. Add 100 μL of each different mass concentration of Standard Intermediate Solution II to each tube. Shake thoroughly and allow to settle. This yields standard working solutions with mass concentrations of 0.50 mg/kg, 1.0 mg/kg, 2.0 mg/kg, 5.0 mg/kg, and 10 mg/kg. Add 2.0 mL of methanol solution to each, vortex for 2 minutes, allow to settle and separate layers, then take 1 mL of the upper clear layer. Filter through a 0.45 μm organic-phase nylon microporous membrane filter for subsequent testing.
4 Instruments and Equipment
4.1 Gas Chromatograph: Equipped with a hydrogen flame ionization detector (FID).
4.2 Analytical Balance: With sensitivities of 0.1 mg and 0.001 g.
4.3 Pipettes: Ranges of 10 μL–200 μL, 1.0 mL, and 10.0 mL.
4.4 Organic-phase nylon microporous filter membrane: Pore size 0.45 μm.
4.5 Vortex mixer.
5 Analytical Procedure
5.1 Preparation of Test Solutions
5.1.1 Migration Test
Food contact materials and articles undergo migration testing per GB 31604.1 and GB 5009.156. If the leachate cannot be tested immediately, store it in a 0°C to 4°C refrigerator away from light for no longer than 48 hours. For subsequent testing, allow the leachate to return to room temperature before use.
5.1.2 Treatment of Immersion Liquids
5.1.2.1 Water-Based Food Simulant Immersion Liquids
Accurately transfer 2.0 mL of the leachate from the migration test into a 10 mL volumetric flask. Dilute with methanol and adjust to the mark. Shake thoroughly. Filter through a 0.45 μm organic-phase nylon microporous membrane filter for subsequent analysis.
5. 1.2.2 Chemical Substitute Solvent (95% Ethanol and Isooctane) Leachate
