National Food Safety Standard - Food Contact Materials and Articles -Determination of Diaminomethylbezen in Complex Food Contact Materials and Articles
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This standard replaces GB/T 5009.119-2013 Determination of Diaminomethylbezen of Complex for Food Packaging Material.
The following changes have been made with respect to GB/T 5009.119-2003 (the previous edition):
——This standard is renamed as National Food Safety Standard - Food Contact Materials and Articles - Determination of Diaminomethylbezen in Complex Food Contact Materials and Articles;
——Migration test condition is modified;
——Selection of derivatization reagent is modified;
——Selection of chromatographic column is modified;
——Gas chromatography-mass spectrometry (GC-MS) is added.
National Food Safety Standard
Food Contact Materials and Articles
Determination of Diaminomethylbezen in Complex Food Contact Materials and Articles
1 Scope
This standard specifies the determination methods of diaminomethylbezen of complex for food packaging material.
This standard is applicable to the determination of diaminomethylbezen of complex for food packaging material.
Method I Gas Chromatography
2 Principle
Leach the diaminomethylbezen in the specimen with 4% acetic acid solution, cool the leach solution, extract with dichloromethane under alkaline condition, add heptafluorobutyric anhydride (HFBA) for derivatization, inject the derivative into a gas chromatograph equipped with electron capture detector for determination, and carry out the qualitative determination by retention time and quantitative determination by external standard method.
3 Reagents and Materials
Unless otherwise specified, analytically-pure reagents and Class-III water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Dichloromethane (CH2Cl2): chromatographically pure.
3.1.2 Tert-butyl methyl ether (C5H12O): chromatographically pure.
3.1.3 Heptafluorobutyric anhydride (C8F14O3): chromatographically pure.
3.1.4 Anhydrous sodium sulfate (Na2SO4).
3.1.5 Sodium chloride (NaCl).
3.1.6 Glacial acetic acid (C2H4O2).
3.1.7 Sodium hydroxide (NaOH).
3.2 Preparation of reagents
3.21 Acetic acid solution (4%): weigh 40 g glacial acetic acid and dissolve in 960 mL water.
3.22 Sodium bicarbonate solution (20 g/L): weigh 2 g sodium bicarbonate, dissolve in water and scale the volume to 100 mL.
3.23 Sodium hydroxide solution (500 g/L): weigh 50 g sodium hydroxide, dissolve in water and scale the volume to 100 mL.
3.3 Standard product
2,4-diaminomethylbezen (C7H10N2, CAS No.: 95-80-7): 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 Diaminomethylbezen standard stock solution: weigh 10 mg (accurate to 0.01 mg) diaminomethylbezen, put into a 50 mL small beaker, dissolve with dichloromethane, transfer to a 100 mL volumetric flask with dichloromethane, scale the volume, mix uniformly, and preserve at 4℃; the mass concentration of diaminomethylbezen is 100 μg/mL.
3.4.2 Diaminomethylbezen standard working solution: pipet 0.50 mL standard stock solution into a 50 mL volumetric flask, scale the volume with dichloromethane to the scale, mix uniformly and preserve at 4℃; the mass concentration of diaminomethylbezen is 1 μg/mL.
4 Instruments and Apparatus
4.1 Gas chromatograph: equipped with electron capture detector.
4.2 Analytical balance: with sensibility of 0.01 mg and 0.01 g.
4.3 Nitrogen evaporator.
4.4 PH meter: accurate to 0.1.
5 Analysis Steps
5.1 Preparation of specimens
5.1.1 Unused food packaging material: wash three times with water, dry it, fill in acetic acid solution as per 2 mL/cm2, and heat-seal it.
5.1.2 Used food packaging material: shear mouth and remove all the food; wash it with fresh water until no dirt, then wash three times with water, dry it, fill in acetic acid solution as per 2 mL/cm2, and heat-seal it.
5.2 Migration test
Place the heat-sealed packaging material mentioned in 5.1.1 or 5.1.2 (with service temperature of 60℃~120℃) into a drying oven preset at 120℃±5℃, keep the constant temperature for 40min, take out, naturally cool to the ambient temperature, cut open and seal, transfer the extract into a dry beaker for standby.
Place the packaging material whose service temperature is less than 60℃ into a drying oven preset at 60℃±5℃, keep the constant temperature for 2 h, take out, naturally cool to the ambient temperature, cut open and seal, transfer the water into a dry beaker for standby.
5.3 Derivatization process
Measure 50.0 mL specimen, put into a separating funnel, adjust the pH value with sodium hydroxide solution to 8.0, mix uniformly, add 10 g sodium chloride, mix uniformly, extract two times with 10 mL dichloromethane respectively (5 min each time), and keep still for 10 min. Merge the two extracting solutions, dehydrate with anhydrous sodium sulfate, blow it with nitrogen at 40℃ until nearly dry, add 2 mL dichloromethane, mix uniformly, add 100 μL heptafluorobutyric anhydride, gently mix uniformly, put under ambient temperature for 15-min derivatization reaction.
Transfer the above reaction solution into a 60 mL separating funnel, clean the concentration flask with 2 mL dichloromethane in several times, merge the cleaning solution into the separating funnel, add 5 mL sodium bicarbonate solution, gently shake for 2 min, keep it still for 5 min, transfer the dichloromethane layer into a 10 mL test tube, blow it with nitrogen at 40℃ until nearly dry, dissolve with tert-butyl methyl ether, scale the volume to 5.00 mL, and inject into the gas chromatograph for analysis.
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 Detection Limit and Quantitation Limit
9 Principle
10 Reagents and Materials
11 Instruments and Apparatus
12 Analysis Steps
13 Expression of Analysis Results
14 Accuracy
15 Detection Limit and Quantitation Limit
Annex A Chromatogram of Standard Diaminomethylbezen Derivative
