GB 31604.57-2023 English PDF

GB 31604.57-2023: National food safety standard - Food contact materials and products - Determination of migration of benzophenone substances
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GB 31604.57-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard - Food Contact Materials
and Products - Determination of Migration of Benzophenone
Substances
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
1 Scope ... 3
Method 1 - Liquid Chromatography ... 3
2 Principle ... 3
3 Reagents and Materials ... 4
4 Instruments and Equipment ... 6
5 Analytical Procedures ... 7
6 Expression of Analysis Results ... 9
7 Precision ... 11
8 Others ... 11
Method 2 - Liquid Chromatography - Tandem Mass Spectrometry ... 12
9 Principle ... 12
10 Reagents and Materials ... 12
11 Instruments and Equipment ... 15
12 Analytical Procedures ... 15
13 Expression of Analysis Results ... 18
14 Precision ... 18
15 Others ... 18
Appendix A Liquid Chromatograms of Standard Solutions of Eight Benzophenones 20
Appendix B Mass Spectrometry Reference Conditions ... 23
Appendix C Liquid Chromatograph - Tandem Mass Spectrometer Total Ions (TIC)
Chromatograms of Eight Benzophenones ... 24
National Food Safety Standard - Food Contact Materials
and Products - Determination of Migration of Benzophenone
Substances
1 Scope
This Standard specifies the methods for the determination of migration of eight benzophenone
substances in food contact materials and products.
Method 1 - liquid chromatography is applicable to the determination of migration of (2-
hydroxy-4-methoxyphenyl) (2-hydroxyphenyl) ketone, 2,4-dihydroxybenzophenone, (2-
hydroxy-4-methoxyphenyl) phenyl ketone, 4-4-dihydroxybenzophenone, 2-hydroxy-4-n-
octoxy-benzophenone, 2-hydroxy-4-n-hexyloxy-benzophenone, benzophenone and 4-4-
difluoro-benzophenone in plastics, paints and coatings, rubber, and food contact materials and
products using inks in water, 4% (volume fraction) acetic acid, 10% (volume fraction) ethanol,
20% (volume fraction) ethanol, 50% (volume fraction) ethanol food simulants, as well as
chemical alternative solvents - 95% (volume fraction) ethanol and isooctane.
Method 2 - liquid chromatography - tandem mass spectrometry is applicable to the
determination of migration of (2-hydroxy-4-methoxyphenyl) (2-hydroxyphenyl) ketone, 2,4-
dihydroxybenzophenone, (2-hydroxy-4-methoxyphenyl) phenyl ketone, 4-4-
dihydroxybenzophenone, 2-hydroxy-4-n-octoxy-benzophenone, 2-hydroxy-4-n-hexyloxy-
benzophenone, benzophenone and 4-4-difluoro-benzophenone in plastics, paints and coatings,
rubber, and food contact materials and products using inks in water, 4% (volume fraction) acetic
acid, 10% (volume fraction) ethanol, 20% (volume fraction) ethanol, 50% (volume fraction)
ethanol and olive oil food simulants, as well as chemical alternative solvents - 95% (volume
fraction) ethanol and isooctane.
Method 1 - Liquid Chromatography
2 Principle
After food contact materials and products are subject to migration test in accordance with GB
31604.1 and GB 5009.156, adopt liquid chromatography for detection. Water, 4% (volume
fraction) acetic acid, 10% (volume fraction) ethanol, 20% (volume fraction) ethanol and 50%
(volume fraction) ethanol food simulants are directly injected; chemical alternative solvent -
95% (volume fraction) ethanol is diluted by water, filtered, then, injected. Use nitrogen to blow
the chemical alternative solvent - isooctane, then, use methanol-water to re-dissolve it, filter,
then, inject the sample. Adopt the external standard method of peak area for quantitative
determination.
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 Glacial acetic acid (CH3COOH).
3.1.2 Absolute ethanol (C2H5OH).
3.1.3 Isooctane (C8H18).
3.1.4 Methanol (CH3OH): chromatographically pure.
3.1.5 Dimethyl sulfoxide (C2H6OS).
3.2 Preparation of Reagents
3.2.1 4% (volume fraction) acetic acid solution, 10% (volume fraction) ethanol solution, 20%
(volume fraction) ethanol solution and 50% (volume fraction) ethanol solution are prepared in
accordance with GB 5009.156.
3.2.2 95% (volume fraction) ethanol solution: evenly mix absolute ethanol and water in a
volume ratio of 95 : 5.
3.2.3 Methanol-water solution (7 + 3): evenly mix methanol and water in a volume ratio of 7 :
3.
3.3 Reference Materials
3.3.1 (2-hydroxy-4-methoxyphenyl) (2-hydroxyphenyl) ketone (C14H12O4, CAS: 131-53-3):
purity  98%, or a standard substance certified by the state and awarded a reference material
certificate.
3.3.2 2,4-dihydroxybenzophenone (C13H10O3, CAS: 131-56-6): purity  98%, or a standard
substance certified by the state and awarded a reference material certificate.
3.3.3 (2-hydroxy-4-methoxyphenyl) phenyl ketone (C14H12O3, CAS: 131-57-7): purity  98%,
or a standard substance certified by the state and awarded a reference material certificate.
3.3.4 4-4-dihydroxybenzophenone (C13H10O3, CAS: 611-99-4): purity  98%, or a standard
substance certified by the state and awarded a reference material certificate.
3.3.5 2-hydroxy-4-n-octoxy-benzophenone (C21H26O3, CAS: 1843-05-6): purity  98%, or a
standard substance certified by the state and awarded a reference material certificate.
3.3.6 2-hydroxy-4-n-hexyloxy-benzophenone (C19H22O3, CAS: 3293-97-8): purity  98%, or a
standard substance certified by the state and awarded a reference material certificate.
3.3.7 Benzophenone (C13H10O, CAS: 119-61-9): purity  98%, or a standard substance certified
by the state and awarded a reference material certificate.
3.3.8 4-4-difluoro-benzophenone (C13H8F2O, CAS: 345-92-6): purity  98%, or a standard
substance certified by the state and awarded a reference material certificate.
3.4 Preparation of Standard Solutions
3.4.1 Standard stock solutions (1,000 mg/L)
Accurately weigh-take 50 mg (accurate to 0.1 mg) of each of the eight benzophenone reference
materials, respectively use methanol to dissolve them, then, transfer them to eight 50 mL
volumetric flasks. Use methanol to reach a constant volume to the scale and evenly mix them.
Transfer the solutions to brown glass containers and store them airtight at 4 C away from light.
They shall remain valid for 6 months.
3.4.2 Standard mixed intermediate solution
Respectively draw-take 0.5 mL of 4-4-dihydroxybenzophenone, benzophenone and 4-4-
difluoro-benzophenone standard stock solutions (1,000 mg/L) and 2.0 mL of the standard stock
solutions (1,000 mg/L) of the other five benzophenone substances into a 100 mL volumetric
flask. Use methanol to reach a constant volume to the scale, evenly mix it to obtain a Standard
mixed intermediate solution, in which, the concentration of 4-4-dihydroxybenzophenone,
benzophenone and 4-4-difluoro-benzophenone is 5.0 mg/L, and the concentration of the other
five benzophenone substances is 20.0 mg/L. Transfer the solution to a brown glass container
and store it airtight at 4 C away from light. It shall remain valid for 3 months.
3.4.3 Standard mixed series of working solutions
3.4.3.1 Standard mixed series of working solutions of water, 4% (volume fraction) acetic
acid, 10% (volume fraction) ethanol, 20% (volume fraction) ethanol and 50% (volume
fraction) ethanol
Respectively draw-take 40 L, 100 L, 200 L, 400 L and 600 L of the standard mixed
intermediate solution into five 10 mL volumetric flasks. Use the corresponding food simulants
to reach a constant volume to the scale, evenly mix them to obtain standard mixed series of
working solutions, in which, the concentration of 4-4-dihydroxybenzophenone, benzophenone
and 4-4-difluoro-benzophenone is 0.020 mg/L, 0.050 mg/L, 0.10 mg/L, 0.20 mg/L and 0.30
mg/L, and the concentration of the other five benzophenone substances is 0.080 mg/L, 0.20
mg/L, 0.40 mg/L, 0.80 mg/L and 1.2 mg/L. Prepare them right before use.
3.4.3.2 Standard mixed series of working solutions of chemical alternative solvent - 95%
(volume fraction) ethanol
5 Analytical Procedures
5.1 Preparation of test solutions
5.1.1 Migration test
In accordance with the requirements of GB 31604.1 and GB 5009.156, conduct a migration test.
After the soaking solution returns to room temperature, handle it in accordance with 5.1.2. If
the soaking solution obtained from the migration test cannot be immediately tested, it shall be
stored in a refrigerator at 4 C away from light for no more than 72 hours. After returning to
room temperature, it shall be handled in accordance with 5.1.2.
5.1.2 Treatment of soaking solutions
5.1.2.1 Food simulant test solutions of water, 4% (volume fraction) acetic acid, 10%
(volume fraction) ethanol, 20% (volume fraction) ethanol and 50% (volume fraction)
ethanol
Transfer-take an appropriate amount of water, 4% (volume fraction) acetic acid, 10% (volume
fraction) ethanol, 20% (volume fraction) ethanol and 50% (volume fraction) ethanol soaking
solutions obtained after the migration test; centrifuge at 5,000 r/min for 5 minutes. Reserve the
supernatant for determination.
5.1.2.2 Chemical alternative solvent - 95% (volume fraction) ethanol test solution
Draw-take 7 mL of 95% (volume fraction) ethanol soaking solution obtained after the migration
test into a 10 mL volumetric flask, use water to reach a constant volume to the scale and evenly
mix it. Take about 1 mL of it and filter it through the microporous filter membrane. Reserve it
for determination.
5.1.2.3 Chemical alternative solvent - isooctane test solution
Draw-take 2 mL of isooctane soaking solution obtained after the migration test into a 10 mL
stoppered centrifuge tube, accurately add 100 L of dimethyl sulfoxide and evenly mix it. In a
40 C water bath, use nitrogen to blow it to near dryness. Accurately add 2 mL of the methanol-
water solution (7 + 3), conduct vortex oscillation for 30 s to dissolve the residue. Take about 1
mL of it and filter it through a microporous filter membrane. Reserve it for determination.
5.1.3 Preparation of blank test solution
In accordance with 5.1.1 and 5.1.2, handle the food simulants and chemical alternative solvents
not in contact with food contact materials and products to obtain blank test solution.
5.2 Reference Conditions of Instrument
5.2.1 Chromatographic column: C18 column, column length 250 mm, inner diameter 4.6 mm,
particle size 5 m; or one with equivalent performance.
6 Expression of Analysis Results
6.1 Calculation of Specific Migration Amount of Benzophenones in Food Contact
Materials and Products of Non-sealed Products (expressed in mg/kg)
For food contact materials and products other than lids, sealing rings, connectors and other
sealing products (hereinafter referred to as sealing products), when expressed in mg/kg, the
specific migration amount of benzophenones is calculated in accordance with Formula (1).
Where,
X1---the specific migration amount of benzophenones, expressed in (mg/kg);
c---the content of benzophenones in the soaking solution, expressed in (mg/L) or (mg/kg);
c0---the content of benzophenones in the blank soaking solution, expressed in (mg/L) or (mg/kg);
V---the volume or mass of the specimen soaking solution in the migration test, expressed in (L)
or (kg);
S---the area of contact between the specimen and the soaking solution in the migration test,
expressed in (dm2);
S0---the area of non-sealed product that comes into contact with food in actual use, expressed
in (dm2);
V1---the mass of non-sealed product that actually comes into contact with solid food, or the
mass of food corresponding to the volume that actually comes into contact with liquid food,
expressed in (kg); the volume of various liquid foods is converted into the corresponding mass
based on a density of 1 kg/L.
If the actual contact area / volume (i.e., S0/V1) of the specimen is unknown, then, the calculation
shall be based on that every 6 dm2 of the specimen area is in contact with 1 kg of food.
The calculation result, which is expressed as the arithmetic mean of the results of two
independent determinations obtained under repeatability conditions, shall at least retain 2
significant figures.
6.2 Calculation of Specific Migration Amount of Benzophenones in Food Contact
Materials and Products of Sealed Products (expressed in mg/kg)
When the intended purpose is known, and the specific migration amount of benzophenones in
food contact materials and products of sealed products is expressed in mg/kg, it is calculated in
accordance with Formula (2).
Where,
X2---the specific migration amount of benzophenones, expressed in (mg/kg);
c---the content of benzophenones in the soaking solution, expressed in (mg/L) or (mg/kg);
c0---the content of benzophenones in the blank soaking solution, expressed in (mg/L) or (mg/kg);
V---the volume or mass of the specimen soaking solution in the migration test, expressed in (L)
or (kg);
S---the area of contact between the specimen and the soaking solution in the migration test,
expressed in (dm2);
S0---the area of sealed product that comes into contact with food in actual use, expressed in
(dm2);
V2---the mass of sealed product that actually uses a container to hold solid food, or the mass of
food corresponding to the volume that actually comes into contact with liquid food, expressed
in (kg); the volume of various liquid foods is converted into the corresponding mass based on
a density of 1 kg/L.
The calculation result, which is expressed as the arithmetic mean of the results of two
independent determinations obtained under repeatability conditions, shall at least retain 2
significant figures.
6.3 Calculation of Specific Migration Amount of Benzophenones in Food Contact
Materials and Products of Sealed Products (expressed in mg/PCS)
When the intended purpose is unknown, and the specific migration amount of benzophenones
in food contact materials and products of sealed products is expressed in mg/PCS, it is
calculated in accordance with...