GB 31604.31-2016 PDF in English
GB 31604.31-2016 (GB31604.31-2016) PDF English
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Determination of residual ethylidene dichloride in polyvinyl chloride resin and product for food container and packaging material
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Standards related to: GB 31604.31-2016
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GB 31604.31-2016: PDF in English GB 31604.31-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard – Food Contact
Materials and Articles – Determination of the
Vinyl Chloride and Determination of Migration
ISSUED ON. OCTOBER 19, 2016
IMPLEMENTED ON. APRIL 19, 2017
Issued by. National Health and Family Planning Commission of PRC
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Principle ... 4
3 Reagents and Materials ... 4
4 Apparatus ... 5
5 Analytical procedures ... 5
6 Expression of Analytical Results ... 7
7 Precision ... 7
8 Others ... 7
9 Principle ... 7
10 Reagents and Materials ... 8
11 Apparatus ... 9
12 Analytical Procedures ... 9
13 Expression of Analytical Results ... 10
14 Precision ... 10
15 Others ... 10
Appendix A Manual Sample Injecting Method ... 11
Appendix B Vinyl Chloride Standard Solution Gas Chromatogram ... 12
National Food Safety Standard – Food Contact
Materials and Articles – Determination of the Vinyl
Chloride and Determination of Migration
1 Scope
This Standard specifies the determination of the vinyl chloride and determination of
migration in plastic and products for food contact materials.
This Standard is applicable to the determination of vinyl chloride and determination of
migration in polyvinyl chloride and vinyl chloride copolymers.
This Standard is also applicable to the determination of 1,1-dichloroethane in polyvinyl
chloride and polyvinyl chloride copolymers.
Determination of Vinyl Chloride
2 Principle
Place the specimen into the sealed balance bottle; use N,N-Dimethylacetamide to
dissolve. At certain temperature, vinyl chloride is diffused; when the gas-liquid
equilibrium is reached, take gas above the liquid to inject into the gas chromatograph;
use hydrogen flame ionization detector to measure, use external standard method to
quantify.
3 Reagents and Materials
Unless otherwise is specified, all reagents shall be analytically pure.
3.1 Reagents
N,N-Dimethylacetamide. purity is greater than 99%.
3.2 Standard substance
Vinyl chloride reference solution. 5000mg/L; take acetone or methanol as solvent.
3.3 Preparation of standard solution
b) Equilibrium temperature. 70°C;
c) Quantitative loop temperature. 90°C;
d) Transmission line temperature. 120°C;
e) Balance time. 30min;
f) Pressurization time. 0.20min;
g) Filling time of quantitative loop. 0.10min;
h) Equilibration time of quantitative loop. 0.10min;
i) Sample injection time. 1.50min.
NOTE. if the manual headspace sampling injection is performed, the reference method can
refer to Appendix A.
5.2.1.2 Chromatographic conditions
a) Chromatographic column. polyethylene glycol capillary chromatographic column
with length of 30m, inner diameter of 0.32mm, film thickness of 1µm, or
equivalent column;
b) Column temperature program. maintain the initial temperature of 40°C for 1min;
raise the temperature to 60°C at the speed rate of 2°C/min, maintain for 1min;
raise the temperature to 200°C at the speed rate of 20°C [Translator note. here
it should be 20°C/min], maintain for 1min;
c) Carrier gas. nitrogen, flow rate of 1mL/min;
d) Sample injecting mode. split, split ratio of 1.1;
e) Sample injecting temperature.200°C;
f) Detector temperature.200°C.
5.2.2 Drawing of standard working curve
The standard working solution prepared in 3.3.2 was tested under the instrumental
parameters listed in 5.2; take the mass concentration of vinyl chloride standard working
solution as abscissa; take the corresponding peak area as the ordinate; then draw the
standard working curve; obtain t he linear equation. Standard solution chromatogram
is shown in Appendix B.
5.2.3 Quantitative determination
10 Reagents and Materials
Unless otherwise is specified, all reagents shall be analytically pure.
10.1 Reagents
10.1.1 Water-based, acidic, alcoholic, oil-fat food simulants. as per the provisions of
GB 31604.1.
10.1.2 N,N-Dimethylacetamide. purity greater than 99%.
10.2 Preparation of reagents
Water-based, acidic, alcoholic, oil-fat food simulants. prepare as per GB 5009.156.
10.3 Standard substance
Vinyl chloride reference solution. 5000mg/L; take acetone or methanol as solvents.
10.4 Preparation of standard solution
10.4.1 Vinyl chloride stock solution. separately add 10mL of N,N-Dimethylacetamide
into 6 pieces of 10mL glass bottles; successively add 5µL, 10µL, 20µL, 30µL, 40µL,
50µL of vinyl chloride into each bottle; mix evenly; then the concentrations of the
obtained vinyl chloride are 2.5mg/L, 5.0mg/L, 10.0mg/L, 15.0mg/L, 20.0mg/L,
25.0mg/L. Store into 4°C refrigerator.
10.4.2 Water-based food simulant standard working solution. separately add 10mL
of water into 6 headspace bottles; successively add 20mL of vinyl chloride stock
solution with different concentrations into each headspace bottles; immediately use
cap to seal; mix evenly; then the concentrations of the obtained vinyl chloride in water
are 0.0050mg/L, 0.010mg/L, 0.020mg/L, 0.030mg/L, 0.040mg/L and 0.050mg/L.
Adopting the same modes, separately use acidic, alcoholic food simulants to prepare
the vinyl chloride serial standard working solution with the same concentration.
10.4.3 Oil-fat food simulant standard working solution. respectively take 10g
(accurate to 0.1g) of oil-fat food simulants into 6 headspace bottles; successively add
20µ of vinyl chloride stock solution with different concentrations into each headspace
bottle; immediately use the cap to seal; mix evenly; the concentrations of the obtained
vinyl chloride in oil-fat food simulants are sequentially 0.0050mg/kg, 0.010mg/kg,
0.020mg/kg, 0.030mg/kg, 0.040mg/kg and 0.050mg/kg.
NOTE. before preparing the standard solution, food simulant needs to be fully cooled in the 4°C
refrigerator; the standard solution shall be prepared quickly.
12.3 Determination
12.3.1 Instrument reference condition
The same as 5.2.
12.3.2 Drawing of standard working curve
The standard working solution is tested as per the measurement conditions listed in
12.3.1. Take the concentration of vinyl chloride in the food simulant standard working
solution as the abscissa; while take the corresponding peak area as the ordinate; then
draw the standard working curve.
12.3.3 Quantitative determination
Sequentially inject the samples of food simulant test solution and blank test solution;
obtain the peak area of vinyl chloride chromatogram; deduct the blank value during the
calculating process. According to the peak area of vinyl chloride chromatogram,
calculate the concentration of vinyl chloride in sample solution by standard curve.
13 Expression of Analytical Results
The concentration of vinyl chloride in the sample solution is obtained from standard
curve; perform migration calculation as per GB 5009.156; obtain the migration of vinyl
chloride in the food contact materials and articles. The calculation results shall be
retained 2 significant figures.
14 Precision
The absolute difference of two independent tests obtained under repeatability
conditions must not exceed 10% of the arithmetic mean.
15 Others
The detection limit of vinyl chloride in the water-based, acidic and alcoholic food
simulants is 0.001mg/L; quantitative limit is 0.005mg/L. The detection limit of vinyl
chloride in the oil-fat food simulant is 0.001mg/kg; quantitative limit is 0.005mg/kg.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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