GB 31604.8-2021 PDF English (GB 31604.8-2016: Older version)

GB31604.8-2021: PDF in English

GB 31604.8-2021 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA Food safety national standard - Food contact materials and products - Determination of total migration ISSUED ON: SEPTEMBER 07, 2021 IMPLEMENTED ON: MARCH 07, 2022 Issued by: National Health Commission of the People's Republic of China; State Administration for Market Regulation. Table of Contents Foreword ... 3  1 Scope ... 4  Part One -- Determination of overall migration in water-based food simulants, chemical alternative solvents ... 4  2 Principle ... 4  3 Reagents and materials ... 4  4 Instruments and equipment... 5  5 Analysis steps ... 5  6 Expression of analysis results ... 7  7 Precision ... 11  Part Two -- Determination of total migration in olive oil ... 11  8 Principle ... 11  9 Reagents and materials ... 12  10 Instruments and equipment... 14  11 Analysis steps ... 14  12 Expression of analysis results ... 20  13 Precision ... 23  Annex A Suitability Judgment ... 25  Annex B Confirmation of moisture-sensitive specimens and adjustment of moisture content -- Vacuum drying method ... 26  Annex C Confirmation of moisture-sensitive specimens and adjustment of moisture content -- Constant humidity method ... 28  Annex D Typical chromatogram ... 30  National Food Safety Standard - Food Contact Materials and Articles Determination of Overall Migration 1 Scope This Standard specifies the methods for determination of overall migration for food contact materials and articles. This Standard is applicable to the determination of overall migration for food contact materials and articles. Part One -- Determination of overall migration in water-based food simulants, chemical alternative solvents 2 Principle The specimen uses water-based food simulants and chemical alternative solvents [such as n-hexane, isooctane, 95% (volume fraction) ethanol solution, n-heptane]. Perform migration test under selected migration test conditions. Evaporate and dry the soaking liquid obtained from the migration test. After deducting the corresponding blanks, the total amount of all non-volatile substances migrated from the specimen to water-based food simulants and chemical substitute solvents is obtained. 3 Reagents and materials Unless otherwise specified, the reagents used in this method are analytically pure, and the water is grade two water specified in GB/T 6682. 3.1 Reagents 3.1.1 Absolute ethanol (C2H6O). 3.1.2 Acetic acid (C2H4O2). chemical substitute solvents Wash and drain the evaporating dish before use. Dry for 2h in a 100°C±5°C electric heating constant temperature drying oven. Then weigh it after cooling for 0.5h in a desiccator. Repeat drying, cooling, and weighing until constant weight (that is, the difference in mass between the two weighings does not exceed 0.5mg). The last weighed mass is the mass of the empty evaporating dish. Take an empty evaporating dish with constant weight. Add 200mL of the soaking solution obtained from the migration test to it (if the evaporating dish specification is < 200mL, it needs to be evaporated to dryness in batches). Place it in a water bath that is not higher than the boiling point of each soaking solution 10°C and evaporate to dryness. Use filter paper or dust-free wipes to absorb the water droplets on the bottom of the evaporating dish (no paper fibers remain at the bottom of the evaporating dish). Then put the evaporating dish in a 100°C±5°C electric heating constant temperature drying box to dry for 2h. Take it out. Cool in a desiccator for 0.5h. Weigh it. Repeat drying, cooling, and weighing until constant weight. The last weighed mass is the mass of the evaporating dish with specimen evaporation residue. The mass of the evaporating dish with the evaporation residue of the specimen minus the mass of the empty evaporating dish is the mass of the soaking solution residue for the specimen determination. 5.3 Determination of trichloromethane extract The determination steps are applicable to food contact materials and articles that require the detection of chloroform extracts in the product standard. Add 20mL of chloroform to the residue obtained in 5.2. Wetting the residue. Use the filter paper to filter. Collect the filtrate into an evaporating dish with constant weight. Then use 20mL of chloroform to extract the residue twice respectively. Use a little chloroform to rinse the filter paper. The filtrate is incorporated into the evaporating dish. Steam to dry according to step 5.2. Obtain the mass of the residue extracted with chloroform from the soaking solution for the specimen determination. 5.4 Blank test Treat water-based food simulants, chemical alternative solvents, and chloroform that are not in contact with food contact materials and articles according to 5.1, 5.2, and 5.3. Obtain the residue mass of the blank soaking solution and the residue mass of the blank soaking solution extracted with chloroform. X6 - Total migration of product contact materials and articles after chloroform extraction, in milligrams per square decimeter (mg/dm2); F - Under foreseeable use cases, the ratio between the area of food contact materials and articles that actually contact the food and the mass of the food (S/V), in square decimeter per kilogram (dm2/kg). The density of various liquid foods is usually calculated as 1kg/L. Convert its volume into the corresponding food mass. When the actual S/V is known, F is the maximum S/V under the foreseeable use case. When the actual S/V is unknown, F uses 6dm2/kg, that is, 6dm2 of food contact materials and articles contact 1kg of food. 6.3 Correction of results When GB 31604.1 stipulates the correction factor for fat-containing food simulants, the determination results of the chemical solvent substitution test shall be divided by the corresponding correction factor. 6.4 Expression of results The calculation result of the total migration amount is expressed as the arithmetic mean of the two parallel determination results obtained under the repeatability condition. The calculation result is accurate to one decimal place. 7 Precision When the total migration result is ≤ 10.0mg/dm2 or 60.0mg/kg, the difference between the two independent determination results obtained under repeatability conditions and the arithmetic mean shall not exceed 1.0mg/dm2 or 6.0mg/kg. The determination result after applying the correction factor shall also meet this requirement. When the total migration result is > 10.0mg/dm2 or 60.0mg/kg, the difference between the two independent determination results obtained under repeatability conditions and the arithmetic mean shall not exceed 10% of the arithmetic mean. The determination result after applying the correction factor shall also meet this requirement. Part Two -- Determination of total migration in olive oil 8 Principle The specimen uses olive oil as a food simulant. The migration test is carried out under the selected conditions. The total migration is determined by the (accurate to 0.1g) potassium hydroxide and dissolve it in 500mL of methanol. Mix well. 9.2.3 Saturated sodium sulfate solution: Weigh 50g (accurate to 0.1g) of anhydrous sodium sulfate in a 250mL beaker. Add 100mL of water on the electric hot plate and boil to dissolve. After cooling to room temperature, use a funnel equipped with qualitative filter paper to filter into a breaker. 9.2.4 Sulfuric acid solution (430g/L): Weigh 215g (accurate to 0.1g) of sulfuric acid. Add slowly to a beaker containing about 300mL of water. Stir while adding. After the solution has cooled to room temperature, transfer to a 500mL volumetric flask. Wash the beaker with a small amount of water 2 to 3 times. Combine the washing liquid into the volumetric flask. Use water to set volume. Prepare it when it is required. When the temperature is 20°C±5°C, the solution is placed in a closed moisture content adjustment container. Maintain a moisture content adjustment environment with a relative humidity of 50% ± 5%. 9.2.5 Sulfuric acid solution (70g/L): Weigh 35g (accurate to 0.1g) of sulfuric acid. Add slowly to a beaker containing about 300mL of water. Stir while adding. After the solution is cooled to room temperature, transfer to a 500mL volumetric flask. Wash the beaker with a small amount of water 2 to 3 times. Combine the washing liquid into the volumetric flask. Use water to set volume. Prepare it when it is required. When the temperature is 20°C±5°C, the solution is placed in a closed moisture content adjustment container. Maintain a moisture content adjustment environment with a relative humidity of 80% ± 5%. 9.3 Standard product Heptadecanoic acid triglyceride (C54H104O6, CAS number: 2438-40-6): Purity ≥98%, or standard material certified by the country and awarded with a standard material certificate. 9.4 Preparation of standard solution 9.4.1 Internal standard solution (2.0mg/mL) Accurately weigh 1.0g (accurate to 0.1mg) of heptadecanoic acid triglyceride. Place in a 100mL beaker. Add cyclohexane to dissolve. Transfer to a 500mL volumetric flask. Wash the beaker 3 times with cyclohexane. The washing liquid is combined into the volumetric flask. Use cyclohexane to set volume. Store in a refrigerator at 4°C. The validity period is 1 month. 9.4.2 Olive oil standard stock solution (100mg/mL) Weigh 5.0g of blank olive oil obtained from migration test (accurate to 0.1mg). Place in a 50mL beaker. Add n-heptane to dissolve. Transfer to a 50mL volumetric flask. Wash the beaker 3 times with n-heptane. The washing liquid multiple products. The number of specimens is determined according to the following purposes: a) Migration test: At least 3 specimens of disposable products; At least 3 specimens per set of specimens for repeated use of articles; b) Volatile matter determination: 2 specimens; c) Suitability judgment (see Annex A): 2 specimens.......
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