Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard replaces GB/T 5009.72-2003 Method for Analysis of Hygienic Standard of Aluminum-wares for Food Use, GB/T 5009.64-2003 Method for Analysis of Hygienic Standard of Rubber Sheet (Ring) for Food Use, GB/T 5009.65-2003 Method for Analysis of Hygienic Standard of Rubber Sealing Ring for Pressure Cooker for Food Use, GB/T 5009.66-2003 Method for Analysis of Hygienic Standard of Nipple of A Feeding Bottle, GB/T 5009.79-2003 Hygienic Analytical Method of Rubber Hose for Food Use, SN/T 2829-2011 Food Contact Materials for Export-metal Materials-Determination of Migrant Heavy Metals in Food Simulant-inductively Coupled Plasma Atomic Emission Spectrometric Method in the determination of zinc migration.
The following main changes have been made with respect to GB/T 5009.72-2003 (the previous edition):
——The standard name is revised as National Food Safety Standard - Determination of Zinc Migration in Food Contact Materials and Articles;
——Flame atomic absorption spectrometry is added;
——Inductively coupled plasma emission spectrometry is added;
——Inductively coupled plasma mass spectrometry (ICP-MS) is added.
National Food Safety Standard
Determination of Zinc Migration in Food Contact Materials and Articles
1 Scope
This standard specifies flame atomic absorption spectrometry, inductively coupled plasma emission spectroscopy, inductively coupled plasma mass spectrometry and dithizone colorimetric method for the determination of zinc migration in food contact materials and articles after soaking in food simulants.
This standard is applicable to the determination of migration of zinc in food contact materials and articles.
Method I Flame Atomic Absorption Spectrometry
2 Principle
The part of food contact materials and articles which are expected to contact with foods soaking in food simulants is adopted for the determination of the zinc content in the sample in the quantitative relation between absorption strength at 213.9nm and its mass concentration, with the soak solution determined by flame atomic absorption spectrometer.
3 Reagents and Materials
Unless otherwise specified, guaranteed reagents and Class-II water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Nitric acid (HNO3).
3.1.2 Reagents required for preparation of food simulants: in accordance with GB 31604.1.
3.2 Preparation of reagents
3.2.1 Food simulants: prepared according to GB 5009.156.
3.2.3 Nitric acid solution (5+95): pipet 5mL nitric acid and dilute with water to 100mL .
3.3 Standard Product
Zinc oxide (ZnO, CAS No.: 1314-13-2): with purity>99.99% or certain concentration of zinc standard solution approved and awarded with reference material certificate by the State.
3.4 Preparation of standard solutions
3.4.1 Zinc standard stock solution (1000mg/L): accurately weigh 1.2447g (accurate to 0.0001g) zinc oxide and add a small amount of nitric acid solution (1+1); heat to dissolve it, transfer it into a 1000mL volumetric flask; add water to the scale and mix uniformly.
3.4.2 Zinc standard intermediate solution (10.0mg/L): pipet 1.00mL zinc standard stock solution, and put it into a 100mL volumetric flask, dilute it with nitric acid solution (5+95) to the scale, mix them uniformly.
3.4.3 Zinc standard series solution: respectively pipet 0mL, 1.00mL, 2.00mL, 4.00mL, 8.00mL and 10.00mL zinc standard intermediate solution into 100mL volumetric flasks, add corresponding food simulants to the scale and mix uniformly. The concentrations of such zinc standard series solution are 0mg/L, 0.100mg/L, 0.200mg/L, 0.400mg/L, 0.800mg/L and 1.00mg/L respectively.
Note: the specific concentration of zinc in standard solution series may be determined according to the sensitivity of instrument, linear range and the actual zinc content in the soak solution. If the selected food simulant is neutral or alkaline, appropriate amount of nitric acid will be required to be added to make the concentration of nitric acid in such solution be about 5% (volume fraction).
4 Instruments and Apparatus
Note: all the glassware shall be soaked in nitric acid (1+5) overnight, flushed with tap water repeatedly, and finally washed clean with water.
4.1 Atomic absorption spectrometer: equipped with flame atomizer and zinc hollow cathode lamp.
4.2 Analytical balance: with sensibility of 0.1mg.
5 Analysis Steps
5.1 Pretreatment of specimen
Carry out migration test according to the intended use and service conditions of to-be-tested sample as well as the migration test methods and conditions specified in GB 5009.156 and GB 31604.1. After the soak solution is fully mixed, take some soaked test solution for analysis. If the soaked test solution is neutral or alkaline, add appropriate amount of nitric acid to make the concentration of nitric acid in such test solution be about 5% (volume fraction). Meanwhile, carry out the specimen blank test.
5.2 Determination
5.2.1 Reference condition of instruments
See A.1 for the reference conditions.
5.2.2 Plotting of standard curve
Respectively lead the standard series solution into flame atomizer from low concentration to high concentration, determine the absorbance value after atomization; plot the standard curve with concentration as x-axis and absorbance value as y-axis.
5.2.3 Determination of specimen solution
Under the same test conditions as those for determination of standard solution, lead the specimen blank and specimen soak solution into the flame atomizer respectively, determine corresponding absorbance value after atomization and compare with the standard series for quantification.
Foreword i 1 Scope 2 Principle 3 Reagents and Materials 4 Instruments and Apparatus 5 Analysis Steps 6 Expression of Analysis Result 7 Accuracy 8 Other 9 Principle 10 Reagents and Materials 11 Instruments and Apparatus 12 Analysis Steps 13 Expression of Analysis Result 14 Accuracy 15 Other Annex A Reference Conditions of Flame Atomic Absorption Method
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard replaces GB/T 5009.72-2003 Method for Analysis of Hygienic Standard of Aluminum-wares for Food Use, GB/T 5009.64-2003 Method for Analysis of Hygienic Standard of Rubber Sheet (Ring) for Food Use, GB/T 5009.65-2003 Method for Analysis of Hygienic Standard of Rubber Sealing Ring for Pressure Cooker for Food Use, GB/T 5009.66-2003 Method for Analysis of Hygienic Standard of Nipple of A Feeding Bottle, GB/T 5009.79-2003 Hygienic Analytical Method of Rubber Hose for Food Use, SN/T 2829-2011 Food Contact Materials for Export-metal Materials-Determination of Migrant Heavy Metals in Food Simulant-inductively Coupled Plasma Atomic Emission Spectrometric Method in the determination of zinc migration.
The following main changes have been made with respect to GB/T 5009.72-2003 (the previous edition):
——The standard name is revised as National Food Safety Standard - Determination of Zinc Migration in Food Contact Materials and Articles;
——Flame atomic absorption spectrometry is added;
——Inductively coupled plasma emission spectrometry is added;
——Inductively coupled plasma mass spectrometry (ICP-MS) is added.
National Food Safety Standard
Determination of Zinc Migration in Food Contact Materials and Articles
1 Scope
This standard specifies flame atomic absorption spectrometry, inductively coupled plasma emission spectroscopy, inductively coupled plasma mass spectrometry and dithizone colorimetric method for the determination of zinc migration in food contact materials and articles after soaking in food simulants.
This standard is applicable to the determination of migration of zinc in food contact materials and articles.
Method I Flame Atomic Absorption Spectrometry
2 Principle
The part of food contact materials and articles which are expected to contact with foods soaking in food simulants is adopted for the determination of the zinc content in the sample in the quantitative relation between absorption strength at 213.9nm and its mass concentration, with the soak solution determined by flame atomic absorption spectrometer.
3 Reagents and Materials
Unless otherwise specified, guaranteed reagents and Class-II water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Nitric acid (HNO3).
3.1.2 Reagents required for preparation of food simulants: in accordance with GB 31604.1.
3.2 Preparation of reagents
3.2.1 Food simulants: prepared according to GB 5009.156.
3.2.2 Nitric acid solution (1+1): measure 500mL nitric acid and add 500mL water, mix uniformly.
3.2.3 Nitric acid solution (5+95): pipet 5mL nitric acid and dilute with water to 100mL .
3.3 Standard Product
Zinc oxide (ZnO, CAS No.: 1314-13-2): with purity>99.99% or certain concentration of zinc standard solution approved and awarded with reference material certificate by the State.
3.4 Preparation of standard solutions
3.4.1 Zinc standard stock solution (1000mg/L): accurately weigh 1.2447g (accurate to 0.0001g) zinc oxide and add a small amount of nitric acid solution (1+1); heat to dissolve it, transfer it into a 1000mL volumetric flask; add water to the scale and mix uniformly.
3.4.2 Zinc standard intermediate solution (10.0mg/L): pipet 1.00mL zinc standard stock solution, and put it into a 100mL volumetric flask, dilute it with nitric acid solution (5+95) to the scale, mix them uniformly.
3.4.3 Zinc standard series solution: respectively pipet 0mL, 1.00mL, 2.00mL, 4.00mL, 8.00mL and 10.00mL zinc standard intermediate solution into 100mL volumetric flasks, add corresponding food simulants to the scale and mix uniformly. The concentrations of such zinc standard series solution are 0mg/L, 0.100mg/L, 0.200mg/L, 0.400mg/L, 0.800mg/L and 1.00mg/L respectively.
Note: the specific concentration of zinc in standard solution series may be determined according to the sensitivity of instrument, linear range and the actual zinc content in the soak solution. If the selected food simulant is neutral or alkaline, appropriate amount of nitric acid will be required to be added to make the concentration of nitric acid in such solution be about 5% (volume fraction).
4 Instruments and Apparatus
Note: all the glassware shall be soaked in nitric acid (1+5) overnight, flushed with tap water repeatedly, and finally washed clean with water.
4.1 Atomic absorption spectrometer: equipped with flame atomizer and zinc hollow cathode lamp.
4.2 Analytical balance: with sensibility of 0.1mg.
5 Analysis Steps
5.1 Pretreatment of specimen
Carry out migration test according to the intended use and service conditions of to-be-tested sample as well as the migration test methods and conditions specified in GB 5009.156 and GB 31604.1. After the soak solution is fully mixed, take some soaked test solution for analysis. If the soaked test solution is neutral or alkaline, add appropriate amount of nitric acid to make the concentration of nitric acid in such test solution be about 5% (volume fraction). Meanwhile, carry out the specimen blank test.
5.2 Determination
5.2.1 Reference condition of instruments
See A.1 for the reference conditions.
5.2.2 Plotting of standard curve
Respectively lead the standard series solution into flame atomizer from low concentration to high concentration, determine the absorbance value after atomization; plot the standard curve with concentration as x-axis and absorbance value as y-axis.
5.2.3 Determination of specimen solution
Under the same test conditions as those for determination of standard solution, lead the specimen blank and specimen soak solution into the flame atomizer respectively, determine corresponding absorbance value after atomization and compare with the standard series for quantification.
Contents of GB 31604.42-2016
Foreword i
1 Scope
2 Principle
3 Reagents and Materials
4 Instruments and Apparatus
5 Analysis Steps
6 Expression of Analysis Result
7 Accuracy
8 Other
9 Principle
10 Reagents and Materials
11 Instruments and Apparatus
12 Analysis Steps
13 Expression of Analysis Result
14 Accuracy
15 Other
Annex A Reference Conditions of Flame Atomic Absorption Method
