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GB 31604.46-2023 PDF English

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GB 31604.46-2023: National food safety standard - Food contact materials and products - Determination of free phenol and migration
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GB 31604.46: Evolution and historical versions

Standard IDContents [version]USDSTEP2[PDF] deliveryName of Chinese StandardStatus
GB 31604.46-2023English335 Add to Cart 0-9 seconds. Auto-delivery National food safety standard - Food contact materials and products - Determination of free phenol and migration Valid
GB 31604.46-2016English70 Add to Cart 0-9 seconds. Auto-delivery Method for analysis of hygienic standard of epoxy phenolic coatings for inner wall of food cans Obsolete

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GB 31604.46-2023: National food safety standard - Food contact materials and products - Determination of free phenol and migration


---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB31604.46-2023
GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National Food Safety Standard - Food Contact Materials and Products - Determination of Free Phenol and Migration Issued on. SEPTEMBER 6, 2023 Implemented on. MARCH 6, 2024 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 1 - Determination of Free Phenol... 4 2 Principle... 4 3 Reagents and Materials... 4 4 Instruments and Equipment... 5 5 Analytical Procedures... 6 6 Expression of Analysis Results... 6 7 Precision... 7 8 Others... 7 Part 2 - Determination of Free Phenol Migration... 7 9 Principle... 7 10 Reagents and Materials... 7 11 Instruments and Equipment... 10 12 Analytical Procedures... 10 13 Expression of Analysis Results... 12 14 Precision... 15 15 Others... 15 Part 3 - Determination of Phenol Migration... 15 16 Principle... 15 17 Reagents and Materials... 15 18 Instruments and Equipment... 17 19 Analytical Procedures... 18 20 Expression of Analysis Results... 20 21 Precision... 21 22 Others... 22 Appendix A Schematic Diagram of Steam Distillation Apparatus... 23 Appendix B Chromatogram of Phenol Standard Working Solution... 24

Foreword

This Standard serves as a replacement of GB 31604.46-2016 National Food Safety Standard - Food Contact Materials and Articles - Determination of Free Phenols and Determination of Migration. In comparison with GB 31604.46-2016, the main changes are as follows. ---The Scope is modified; ---The detection limit and quantitation limit in Part 1 are modified; ---The analytical procedures and result expression in Part 2 are modified; ---Part 3 - The Determination of Phenol Migration is added. National Food Safety Standard - Food Contact Materials and Products - Determination of Free Phenol and Migration

1 Scope

This Standard specifies the method for the determination of food contact materials and products - free phenol and the determination of migration. In this Standard, Part 1 is applicable to the determination of free phenol in epoxy phenolic resin coatings for food contact; Part 2 is applicable to the determination of free phenol migration in food contact materials and products; Part 3 is applicable to the determination of phenol migration in food contact materials and products. Part 1 - Determination of Free Phenol

2 Principle

The free phenol in the specimen reacts with bromine to generate bromophenol. The remaining bromine reacts with potassium iodide. The precipitated iodine is titrated with sodium thiosulfate. In accordance with the consumption of sodium thiosulfate solution, calculate the content of free phenol.

3 Reagents and Materials

Unless it is otherwise specified, the reagents used in this Method are all analytically pure, and the water is Grade-1 water specified in GB/T 6682. 3.1 Reagents 3.1.1 Hydrochloric acid (HCl). mass fraction 36% ~ 38%. 3.1.2 Trichloromethane (CHCl3). 3.1.3 Ethanol (C2H6O). 3.2 Preparation of Reagents 3.3 Reference Materials 3.3.1 Sodium thiosulfate pentahydrate (Na2S2O3  5H2O, CAS No.. 10102-17-7). working reference reagent, or a standard substance certified by the state and awarded a reference material certificate. 3.3.2 Potassium bromate (KBrO3, CAS No.. 7758-01-2). working reference reagent, or a standard substance certified by the state and awarded a reference material certificate. 3.4 Preparation of Standard Solutions

4 Instruments and Equipment

4.1 Balance. with a division value of 0.01 g and 0.1 mg, respectively.

5 Analytical Procedures

5.1 Distillation of Specimens Weigh-take 1.0 g (accurate to 0.01 g) of epoxy phenolic resin coating specimen for food contact, put it into a distillation bottle, add 20 mL of ethanol to dissolve it (for water-based modified epoxy resin coatings, add 20 mL of water). Add 50 mL of water, then, use steam to distill off free phenol. Collect the distilled solution in a 500 mL conical flash. Within 40 min ~ 50 min, distill 300 mL ~ 400 mL of distilled liquid. 5.2 Titration Transfer-take 100 mL of distilled liquid, place it in a 500 mL stoppered conical flask, add 25 mL of bromine standard solution and 5 mL of hydrochloric acid. At room temperature, use a stopper to cover it to avoid light, and react for 15 min. 5.3 Blank Test Take 20 mL of ethanol and use water to dilute it to 500 mL, then, transfer-take 100 mL of the diluted solution (for water-based modified epoxy resin coatings, transfer-take 100 mL of water). In accordance with the method of 5.2, conduct the determination.

6 Expression of Analysis Results

The content of free phenol in the sample is calculated in accordance with Formula (1).

7 Precision

The absolute difference between the results of two independent determinations obtained under repeatability conditions shall not exceed 5% of the arithmetic mean.

8 Others

In this method, the detection limit is 0.4 g/kg and the quantitation limit is 2.0 g/kg.

9 Principle

Under alkaline conditions (pH 9.0 ~ 10.5), free phenol reacts with 4-aminoantipyrine under the catalysis of potassium ferricyanide to generate antipyrine dye. The antipyrine dye in water is extracted with chloroform.

10 Reagents and Materials

Unless it is otherwise specified, the reagents used in this Method are all analytically pure, and the water is Grade-1 water specified in GB/T 6682. 10.1 Reagents 10.1.1 Absolute ethanol (C2H6O). 10.1.2 Glacial acetic acid (C2H4O2). 10.1.3 Isooctane (C8H18). 10.2 Preparation of Reagents 10.2.1 Water-based food simulants. in accordance with the stipulations of GB 5009.156, conduct the preparation. 10.3 Reference Material Phenol (C6H6O, CAS No.. 108-95-2). with a purity > 99%, or a standard substance certified by the state and awarded a reference material certificate. 10.4 Preparation of Standard Solutions 10.4.7 Standard series of working solutions in isooctane Respectively and accurately transfer-take 0 mL, 0.25 mL, 0.50 mL, 1.00 mL, 1.50 mL and 3.00 mL of the standard intermediate solution (100 mg/L) into six 50 mL volumetric flasks; use isooctane to reach a constant volume to the scale and evenly mix them. The concentration of phenol in the standard series of working solutions is respectively 0.00 mg/L, 0.50 mg/L, 1.00 mg/L, 2.00 mg/L, 3.00 mg/L and 6.00 mg/L. 10.5 Material Nylon filter membrane. with a pore size of 0.45 m.

11 Instruments and Equipment

11.1 Visible spectrophotometer. 11.3 Distillation apparatus.

12 Analytical Procedures

12.1 Migration Test Food contact materials and products shall be subject to migration test in accordance with the requirements of GB 31604.1 and GB 5009.156. 12.2 Pre-treatment of Soaking Solutions 12.3 Blank Test In accordance with 12.1 and 12.2, conduct the treatment on food simulants and chemical alternative solvents that are not in contact with the food contact materials and products. 12.4 Drawing of Standard Curve After the standard series of working solutions in the various food simulants and chemical alternative solvents are treated in the same way as the corresponding soaking solution, in accordance with the conditions specified in Table 1, determine the absorbance of the standard series of working solutions in each food simulant. Take the absorbance of the standard working solution as the y-coordinate and the mass concentration of phenol in the corresponding standard working solution as the x-coordinate to draw the standard curve. ......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.


      

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