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This standard replaces GB/T 23296.25-2009 Food Contact Materials - Polymer - Determination of 1,3-benzenedimethanamine in Food Simulants - High Performance Liquid Chromatography and SN/T 2550-2010 Food Contact Materials - Polymer Materials - Determination of 1,3-benzenedimethanamine in Food Simulants - High Performance Liquid Chromatography.
The following main changes have been made with respect to GB/T 23296.25-2009 (the previous edition):
——The standard name is renamed as “National Food Safety Standard - Food Contact Materials and Articles - Determination of Migration of 1,3-benzenedimethanamine”.
National Food Safety Standard
Food Contact Materials and Articles
Determination of Migration of
1,3-benzenedimethanamine
1 Scope
This standard specifies the high performance liquid chromatography for the determination of migration of 1,3-benzenedimethanamine in food contact materials and articles.
This standard is applicable to the determination of migration of 1,3-benzenedimethanamine in food contact materials and articles.
2 Principle
After migration test of food contact materials, carry out fluorescamine derivation for 1,3-benzenedimethanamine in water-based, acidic and alcoholic food simulants, and then separate through high performance liquid chromatography, with fluorescence detector adopted for examination and external standard method adopted for quantitation; as for 1,3-benzenedimethanamine in oil-based simulant, the same method shall be adopted for examination after extraction by 4% acetic acid solution.
3 Reagents and Materials
Unless otherwise specified, analytically-pure reagents and Class-I water (defined in GB/T 6682 and saturated with nitrogen) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Water-based, acidic, alcoholic and oil-based food simulants: the reagents adopted shall comply with the requirements of GB 31604.1.
3.1.2 Methanol (CH4O, CAS No.: 67-56-1): chromatographically pure.
3.1.3 Tetrahydrofuran (C4H8O, CAS No.: 109-99-9): chromatographically pure.
3.1.4 Acetone (C3H6O, CAS No.: 67-64-1).
3.1.5 Heptane (C7H16, CAS No.: 142-82-5).
3.1.6 Acetic acid (C2H4O2, CAS No.: 64-19-7).
3.1.7 Fluorescamine (C17H10O4, CAS No.：38183-12-9): with purity ≥98%.
3.1.8 Sodium tetraborate decahydrate (Na2B4O7·10H2O, CAS No.: 1330-43-4).
3.1.9 Sodium hydroxide (NaOH, CAS No.: 1310-73-2).
3.1.10 Nitrogen (99.999%).
3.2 Preparation of reagents
3.2.1 Water-based, acidic, alcoholic and oil-based food simulants: operate in accordance with GB 5009.156.
3.2.2 Tetrahydrofuran solution (with volume fraction of 90%): measure 90 mL of tetrahydrofuran and put it into a volumetric flask (100mL) and dilute with water to the scale.
3.2.3 Fluorescamine solution (2 mg/mL): weigh 50mg (accurate to 0.0001g) of fluorescamine, and scale the volume to 25mL after dissolution with acetone; the solution shall be stored in a dark place at 5℃, with validity period of one week.
3.2.4 Sodium hydroxide solution (5 mol/L): weigh 20g of sodium hydroxide, dissolve it with water and scale the volume to 100mL.
3.2.5 Boric acid buffer solution (0.15 mol/L，pH=9.2): weigh 14.3g of sodium tetraborate decahydrate, dissolve it with water and scale the volume to 250mL. Before using the solution, resolution is required in case of precipitation caused by temperature reduction.
3.2.6 Acetic acid solution (with mass concentration of 4%): weigh 20g of acetic acid, dissolve it with water and scale the volume to 500mL.
3.2.7 Boric acid buffer solution (0.02 mol/L，pH=9.2): pipet 133mL of 0.15 mol/L boric acid buffer solution (3.2.5), dilute with water and scale the volume to 1L.
3.2.8 High performance liquid chromatography mobile phase [boric acid buffer solution: water: methanol (18: 37: 45)]: pipet 180mL of 0.02 moL boric acid buffer solution (3.2.7), 370mL of water and 450mL of methanol, and mix them.
3.3 Standard products
1,3-benzenedimethanamine standard product (C8H12N2, CAS No.: 1477-55-0): with purity ≥99%, or reference material approved and awarded with reference material certificate by the state.
3.4 Preparation of standard solutions
3.4.1 1,3-benzenedimethanamine standard stock solution
Weigh 50 mg (accurate to 0.0001g) of 1,3-benzenedimethanamine, dissolve it with water and scale the volume to 50mL, with the concentration of 1,000 mg/L; the solution shall be stored in a dark place at 5℃, with validity period of three months.
3.4.2 1,3-benzenedimethanamine standard working solution used for water-based (acidic or alcoholic) food simulants
Pipet 0.20 mL of 1,3-benzenedimethanamine standard working solution (3.4.1) into a volumetric flask (100mL) with the graduated pipette, dilute to the scale with water-based (acidic or alcoholic) food simulants, and obtain 1,3-benzenedimethanamine standard working solution with concentration of 2.0 mg/L used for water-based (acidic or alcoholic) food simulants; the solution shall be stored in a dark place at 5℃, with validity period of one month.
3.4.3 1,3-benzenedimethanamine standard working solution used for oil-based simulants
Pipet 2.0 mL of 1,3-benzenedimethanamine standard working solution (3.4.1) into a volumetric flask (100mL) with the graduated pipette, dilute with water to the scale, and obtain the solution with concentration of 20 mg/L; pipet 10 mL of the solution into a volumetric flask (100mL) , dilute with tetrahydrofuran solution (3.2.2) to the scale, and obtain 1,3-benzenedimethanamine standard working solution with concentration of 2.0 mg/L used for oil-based simulants; the solution shall be stored in a dark place at 5℃, with validity period of one month.
3.4.4 1,3-benzenedimethanamine standard working solution of water-based (or alcoholic) food simulants
Pipet 0.5 mL, 2.0 mL, 3.0 mL, 4.0 mL and 5.0 mL of 1,3-benzenedimethanamine standard working solution (3.4.2) into five volumetric flasks (100mL) with the graduated pipette respectively, scale the volume to the scale with corresponding food simulants (water-based or alcoholic food simulants), and obtain the standard working solution with the concentration of 0.010 mg/L, 0.040 mg/L, 0.060 mg/L, 0.080 mg/L and 0.10 mg/L respectively; pipet 2.0 mL of the above-mentioned solutions respectively into five test tubes (5mL) with the graduated pipette, add 0.4 mL of boric acid buffer solution (3.2.5) respectively, and mix uniformly and sufficiently; add 300 μL of derivative reagent of fluorescamine solution (3.2.3) respectively, oscillate for 1min and keep it still for 10 min. Filter the derivative solution through the 0.45 μm filter membrane for sample injection of high performance liquid chromatograph.
3.4.5 1,3-benzenedimethanamine standard working solution of acidic food simulants
Pipet 0.5 mL, 2.0 mL, 3.0 mL, 4.0 mL and 5.0 mL of 1,3-benzenedimethanamine standard working solution (3.4.2) in acidic food simulants into five volumetric flasks (100mL) with the graduated pipette respectively, scale the volume to the scale with acidic food simulants, and obtain the standard working solutions with the concentration of 0.010 mg/L, 0.040 mg/L, 0.060 mg/L, 0.080 mg/L and 0.10 mg/L respectively; accurately pipet 10.0 mL of the above-mentioned solution respectively into five beakers (25mL), add 5mol/L sodium hydroxide solution (3.2.4) into the first beaker by drops, adjust the pH value to 9.2, and calculate the volume of sodium hydroxide solution required (accurate to 0.01 mL); accurately add sodium hydroxide solution (3.2.4) of the above-mentioned volume into the rest four beakers, and mix uniformly and sufficiently (the pH value of the solution shall be within the range of 8.0~9.9). The following steps shall be operated according to "pipet 2.0 mL of the above-mentioned solution respectively…for sample injection of high performance liquid chromatograph" in 3.4.4.
3.4.6 Oil-based food simulants standard working solution
Weigh 20.0 g (accurate to 0.01 g) of oil-based simulants respectively and put them into five separating funnels (125 mL), then respectively pipet 0.2 mL, 0.4 mL, 0.6 mL, 0.8 mL and 1.0 mL of 1,3-benzenedimethanamine standard working solution (3.4.3) into the five separating funnels (125 mL) with the graduated pipette; accurately add in 0.8 mL, 0.6 mL, 0.4 mL, 0.2 mL and 0 mL of tetrahydrofuran solution (3.2.2) and 5.0 mL of heptane respectively, mix uniformly and sufficiently, then add 20.0 mL of acetic acid solution (3.2.6), oscillate for 5min and keep it still for 15 min; after complete separation of two phases, collect the aqueous phase extracts, and obtain oil-based food simulants standard working solution with the concentration of 0.02 mg/kg, 0.04 mg/kg, 0.06 mg/kg, 0.08 mg/kg and 0.10 mg/kg respectively; accurately transfer 10.0 mL of the above-mentioned solution into five beakers (25mL) respectively, add 5mol/L sodium hydroxide solution (3.2.4) into the first beaker by drops, adjust the pH value to 9.2, and calculate the volume of sodium hydroxide solution required (accurate to 0.01 mL); accurately add sodium hydroxide solution (3.2.4) of the above-mentioned volume into the rest four beakers, and mix uniformly and sufficiently (the pH value of the solution shall be within the range of 8.0~9.9). The following steps shall be operated according to "pipet 2.0 mL of the above-mentioned solution respectively…for sample injection of high performance liquid chromatograph" in 3.4.4.
4 Instruments and Apparatus
4.1 High-performance liquid chromatograph: equipped with fluorescence detector (FLD).
4.2 Analytical balance: with the sensitivity of 0.0001g.
4.3 Vortex mixer.
4.4 Mechanical oscillator.
4.5 0.45μm microporous filter membrane.
4.6 Thermostatic waterbath.
5 Analysis Steps
5.1 Specimen migration test
Carry out migration test in accordance with the requirements of GB 5009.156 and GB 31604.1 for the sample, and obtain the food simulant test solution; if the obtained food simulant test solution fails to be used for the next test immediately, it shall be kept in dark place in a refrigerator at 4℃.
The obtained food simulant test solution shall be cooled or recovered to ambient temperature for the next step of the test.
5.2 Test solution preparation
5.2.1 Preparation of water-based and alcoholic food simulants
Pipet 2.0 mL of water-based (alcoholic) food simulants obtained from migration test into a test tube (5mL) with the graduated pipette, add 0.4 mL of boric acid buffer solution, and mix uniformly and sufficiently; then add 300 μL of derivative reagent of fluorescamine solution, oscillate for 1min and keep it still for 10 min. Filter the derivative solution through 0.45 μm filter membrane for sample injection of high performance liquid chromatograph.
5.2.2 Preparation of acidic food simulants
Pipet 10.0 mL of acidic food simulants obtained from migration test into a beaker (25mL) with the graduated pipette, add 5 mol/L sodium hydroxide solution (3.2.4) with the same volume as that of sodium hydroxide solution in 3.4.5 by drops, and mix uniformly and sufficiently (the pH value of the solution shall be within the range of 8.0~9.9). Pipet 2.0 mL of the above-mentioned solution into a test tube (5mL) with the graduated pipette, and the following steps shall be operated according to "add 0.4 mL of boric acid buffer solution… for sample injection of high performance liquid chromatograph" in 5.2.1.
Foreword i
1 Scope
2 Principle
3 Reagents and Materials
4 Instruments and Apparatus
5 Analysis Steps
6 Expression of Analysis Results
7 Accuracy
8 Others
Annex A Liquid Chromatogram
