GB 31604.62-2025 National food safety standard - Food contact materials and products - Determination of migration and release of N- nitrosamines English, Anglais, Englisch, Inglés, えいご
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National Standard of the People's Republic of China
GB 31604.62-2025
National Food Safety Standard - Food Contact Materials and Articles - Determination of migration and release of N- nitrosamines
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 Articles
N-Nitrosamines Determination of Migration and Release Levels
1 Scope
This standard specifies methods for determining the migration and release levels of N-nitrosamine compounds and N-nitrosamine precursors in food contact materials and articles.
Part 1 of this standard applies to the determination of N-dimethylnitrosamine, N-nitroso-N-methylethanamine, N-Nitrosodiethylamine, N-Nitrosodiisopropylamine, N-Nitrosodipropylamine, N-Nitrosodiisobutylamine, N-Nitrosodipropylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, N-nitrosomorpholine, N-nitroso-N-ethylbenzenamine, N-nitroso-N-methylbenzenamine, N-nitrosodiiroctanamide, N-nitrosodicyclohexylamine, N-nitrosodibenzylamine, and other 15 N-nitrosamine compounds. It is also applicable to the determination of migration levels of the aforementioned 15 N-nitrosamine precursors in rubber materials and products intended for food contact. Part 2 of this standard applies to the determination of the release levels of the aforementioned 15 N-nitrosamine compounds in pacifiers and is also applicable to the determination of the release levels of the aforementioned 15 N-nitrosamine precursors in pacifiers.
Part 1 Determination of Migration Levels of N-Nitrosamine Compounds and N-Nitrosamine Precursors
Method 1: Gas Chromatography-Mass Spectrometry (GC-MS)
2. Principle
N-nitrosamine compounds in the leachate obtained from migration tests are extracted with dichloromethane under alkaline conditions, concentrated, and then determined using a gas chromatograph-mass spectrometer (GC-MS). Quantification is performed by the external standard method to obtain the migration amount of directly migrated N-nitrosamine compounds.
N-nitrosamine precursors in the migration test extract react with nitrites in artificial saliva under acidic conditions to form N-nitrosamines. The resulting N-nitrosamines and the directly migrated N-nitrosamines were simultaneously determined using the aforementioned steps to obtain the sum of migration amounts for both N-nitrosamine precursors and directly migrated N-nitrosamines. The migration amount of a single N-nitrosamine precursor is calculated by subtracting the migration amount of the corresponding directly migrated N-nitrosamine from the sum of the measured migration amounts.
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 Dichloromethane (CH₂Cl₂): Chromatographic grade.
3.1.2 Concentrated hydrochloric acid (HCl).
3.1.3 Sodium hydroxide (NaOH).
3.1.4 Anhydrous ethanol (C₂H₆O): Chromatographic grade.
3.1.5 Glacial acetic acid (C₂H₄O₂): High-purity grade.
3.1.6 Sodium bicarbonate (NaHCO₃).
3.1.7 Sodium chloride (NaCl).
3.1.8 Potassium carbonate (K₂CO₃).
3.1.9 Sodium nitrite (NaNO₂).
3.2 Reagent Preparation
3.2.1 Food simulant: Prepared according to GB 5009.156.
3.2.2 0.1 mol/L hydrochloric acid solution: Prepared according to GB 5009.156.
3.2.3 0.1 mol/L sodium hydroxide solution: Prepared according to GB 5009.156.
3.2.4 1 mol/L hydrochloric acid solution: Measure 83 mL hydrochloric acid and slowly add to 500 mL water. After cooling to room temperature, transfer to a 1 L volumetric flask, dilute to the mark with water, and mix thoroughly.
3.2.5 5 mol/L Sodium Hydroxide Solution: Weigh 5.0 g of sodium hydroxide into a polyethylene or polytetrafluoroethylene beaker. Dissolve in 250 mL water. After cooling, transfer to a plastic bottle (excluding PET) for later use.
3.2.6 Artificial Saliva: Prepare according to GB 5009.156 or procure commercially available artificial saliva.
3.3 Standards/Substances
15 N-nitrosamine Compound Standards: Purity >98% for all; specific details refer to Table A.1 in Appendix A, or use nationally certified standards with a Certificate of Analysis.
3.4 Standard Solution Preparation
3.4.1 Mixed Standard Stock Solution of 15 N-Nitrosamines (100 mg/L): Accurately weigh 25 mg of each of the 15 N-nitrosamine compound reference materials (accurate to 0.1 mg). Dissolve in anhydrous ethanol and transfer to a 250 mL brown volumetric flask. Dilute to the mark with ethanol and mix thoroughly. Transfer the solution to a brown glass container. Store at -18°C protected from light. Shelf life: 6 months.
3.4.2 Mixed N-Nitrosamine Compound Intermediate Standard Solution (1.00 mg/L): Accurately transfer 1.00 mL of the 15-compound mixed N-nitrosamine standard stock solution (100 mg/L) into a 100 mL brown volumetric flask. Dilute to the mark with anhydrous ethanol and mix thoroughly. Transfer the solution to a brown glass container. Store at -18°C protected from light. Shelf life: 3 months.
3.4.3 Mixed Standard Series Working Solutions: Pipette 0.50 mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL, and 5.00 mL of the N-nitrosamine compound mixed standard intermediate solution (1.00 mg/L) into six separate 10 mL volumetric flasks. 0.50 mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL, and 5.00 mL into six 10 mL brown volumetric flasks. Dilute to the mark with anhydrous ethanol and mix thoroughly. The mass concentrations of the 15 N-nitrosamine compounds are 0.0500 mg/L, 0.100 mg/L, 0. 200 mg/L, 0.300 mg/L, 0.400 mg/L, and 0.500 mg/L. Prepare fresh working solutions as needed.
4 Instruments and Equipment
4.1 Gas Chromatograph-Mass Spectrometer (GC-MS): Equipped with an electron impact ionization source (EI source).
4.2 Electronic Balance: Sensitivities of 0.1 g and 0.1 mg.
4.3 Electric Hot-Air Drying Oven.
4.4 Rotary Evaporator: Equipped with vacuum apparatus and water-cooling system.
4.5 Nitrogen Blower.
4.6 pH Meter: Accuracy 0.1.
4.7 Microporous Filter Membrane: Nylon, pore size 0.22 μm.
4.8 Separating funnel: 150 mL, equipped with PTFE stopper.
5 Analytical Procedures
5.1 Migration Test
