National food safety standard
Food contact materials and articles –Determination of aromatic primary amine migration
1 Scope
This standard specifies the determination method of migration of 29 aromatic primary amines in food contact materials and articles.
This standard is applicable to the determination of aromatic primary amine migration for food contact materials and articles.
2 Principle
The food contact materials and articles shall be subjected to testing using liquid chromatography-mass spectrometry/mass spectrometry method after migration test according to GB 31604.1 and GB 5009.156. During which, food simulants of 4% acetic acid, 10% ethanol, 20% ethanol and 50% ethanol and chemical alternative solvent of 95% ethanol are filtered and directly injected; chemical alternative solvent of isooctane is extracted by methanol aqueous solution and then the water layer thereof is filtered for injection. Then quantification is made by external standard method.
3 Reagents and materials
Class-I water specified in GB/T 6682 is adopted.
3.1 Reagents
3.1.1 Acid and alcoholic food simulants and chemical alternative solvents: the reagents used are in accordance with the requirements of GB 5009.156.
3.1.2 Methanol (CH3OH): chromatographically pure.
3.1.3 Methanoic acid (HCOOH): chromatographically pure.
3.1.4 Acetonitrile (CH3CN): chromatographically pure.
3.1.5 Glacial acetic acid (CH3COOH): guaranteed reagent.
3.1.6 Isooctane (C8H18): chromatographically pure.
3.2 Preparation of reagents
3.2.1 Acidic and alcoholic food simulants and chemical alternative solvents: prepared according to GB 5009.156.
3.2.2 0.1% methanoic acid: put 1mL methanoic acid (3.1.3) into a volumetric flask, and dilute it to 1L with water.
3.2.3 Methanol-water extract: measure 50mL methanol (3.1.2) and 50mL water, pipette 0.4mL glacial acetic acid (3.1.5) and mix well.
3.3 Standards
29 aromatic primary amines: standards (see Annex A), with a purity of ≥98%; or standard material certified by the state and granted with standard material certificate.
3.4 Preparation of standard solutions
3.4.1 Standard stock solutions of 29 aromatic primary amines (1,000mg/L): accurately weigh 25mg (accurate to 0.1mg) of each standard of 29 aromatic primary amines, dissolve in methanol, transfer into a 25mL brown volumetric flask, dilute with methanol to the scale, and then store in the refrigerator at 4℃ in a dark place for 1 month.
3.4.2 Standard intermediate solutions A of aromatic primary amines (1mg/L, methanol): pipette 10μL of each standard stock solution of 29 aromatic primary amines into a 10mL brown volumetric flask, dilute with methanol to the scale, and then store in the refrigerator at 4℃ in a dark place for 1 month.
3.4.3 Standard intermediate solutions B of aromatic primary amine (1mg/L, isooctane): pipette 10μL of each standard stock solution of 29 aromatic primary amines into a 10mL brown volumetric flask, dilute with isooctane to the scale, and then store in the refrigerator at 4℃ in a dark place for 1 month.
3.4.4 Preparation of standard working solutions
3.4.4.1 Isooctane standard working solutions
Accurately pipette 30μL, 50μL, 100μL, 300μL and 500μL standard intermediate solutions B (3.4.3) of aromatic primary amines into 10mL volumetric flasks, and dilute with isooctane to the scale to obtain standard working solutions with aromatic primary amine concentrations of 3.0ug/L, 5.0ug/L, 10.0μg/L, 30.0μg/L and 50.0μg/L respectively. Transfer 2mL isooctane standard working solution into a test tube, add 2mL methanol-water extract (3.2.3), shake for 30s, stand for layering, then take the lower layer of aqueous solution, and filter it with nylon membrane for determination.
3.4.4.2 Standard working solutions of other food simulants and chemical alternative solvents
1 Scope
2 Principle
3 Reagents and materials
4 Instruments and equipment
5 Analytical procedures
6 Expression of analysis results
7 Precision
8 Other requirements
Annex A Names, CAS numbers and molecular formulas of 29 aromatic primary amines
Annex B Mass spectrometry reference conditions
Annex C Total ion current (TIC) chromatograms and multi-reaction monitoring (MRM) chromatograms of 29 aromatic primary amines by liquid chromatography-mass spectrometry/mass spectrometry