GB Translated English of Chinese Standard: GB NATIONAL STANDARD OF

Transcription

1 Translated English of Chinese Standard: GB NATIONAL STANDARD OF GB THE PEOPLE S REPUBLIC OF CHINA GB National Food Safety Standard Food contact materials and products Determination of heavy metals in food simulants 食品安全国家标准食品接触材料及制品食品模拟物中重金属的测定 Issued on: August 31, 2016 Implemented on: March 1, 2017 Issued by: National Health and Family Planning of China Page 1 of 9

2 Table of Contents Foreword Scope... 4 Method One Direct colorimetric method Principle Reagents and materials Apparatus Analysis steps Expression of analysis results... 6 Method Two Masking interference colorimetric method Principle Reagents and materials Apparatus Analysis steps Expression of analysis results Page 2 of 9

3 Foreword This Standard replaces GB/T Method for Analysis of Hygienic Standard of Products of Polyethylene, Polystyrene and Polypropyrene for Food Packaging, GB/T Method for analysis of hygienic standard of products of tripolycyanamide for food packaging, GB/T Method for analysis of hygienic standard of rubber sheet (ring) for food use, GB/T Method for analysis of hygienic standard of rubber sealing ring for pressure cooker for food use, GB/T Method for analysis of hygienic standard of nipple of a feeding bottle, GB/T Method for analysis of hygienic standard of product of polyvinyl chloride for food packaging, GB/T Method for analysis of hygienic standard of perchlorovinylcoating for inner wall of food container, GB/T Method for analysis of hygienic standard of epoxy coating for inner wall of food container, GB/T Hygienic analytical method of rubber hose for food use, GB/T Method for analysis of hygienic standard of unsaturated polyester resin and glass fibre reinforced product, GB/T Method for analysis of hygienic standard of polycarbonate resin used as food containers and packaging, GB/T Method for analysis of hygienic standard of products of foamed polystyrene for food packaging. Compared with GB/T and other standard replaced by this Standard, the main changes in this Standard are as follows: - modified the standard s name to National Food Safety Standard - Food contact materials and products - Determination of heavy metals in food simulants ; - modified the expression of the applicable scope; - modified the expression of principle; - deleted the sampling methods in each previous standard; - deleted the soaking conditions in each previous standard; - modified the expression of analysis results. Page 3 of 9

4 National Food Safety Standard Food contact materials and products Determination of heavy metals in food simulants 1 Scope This Standard specifies the determination of heavy metals in food simulants (4% acetic acid). The Method One of this Standard applies to the determination of heavy metals of food contact materials and products in food simulants (4% acetic acid). The Method Two of his Standard applies to the determination of heavy metals of food contact rubber products in food simulants (4% acetic acid). Method One Direct colorimetric method 2 Principle The heavy metal (in terms of lead) in the food simulant test solution obtained by the migration test INTERACTS with sodium sulfide to FORM yellow-brown sulfide in acidic solution and COMPARE with the color of lead standard solution. 3 Reagents and materials NOTE Unless otherwise stated, the reagents used in this method are of analytical grade and water is Grade Two specified in GB/T Reagents Sodium sulfide hydrate (Na2S 9H2O) Glycerol (C3H8O3) Glacial acetic acid (CH3COOH) Nitric acid (HNO3, 60%, mass fraction) 3.2 Preparation of reagents Page 4 of 9

5 8.4.2 Lead standard use solution: pipet 10.0 ml of lead standard stock solution (8.4.1); place it in a 100 ml volumetric flask; add water to dilute to scale. well mix. OR pipet 1.0 ml of lead standard solution (8.3.1) certified by the state and awarded the standard material certificate; place it in a 100 ml volumetric flask; use water to dilute to scale; well mix. 1 ml of this solution is equivalent to 10 μg of lead. 9 Apparatus 9.1 Constant temperature oven 9.2 Volumetric flasks: 100 ml, 1000 ml 9.3 Pipettes: 10 ml, 20 ml 9.4 Color comparison tube: 50 ml 9.5 Measuring tube: 50 ml 9.6 Analytical balances: resolutions of g, 0.1 g 10 Analysis steps 10.1 Sample preparation Samples shall be subjected to migration test by using 4% acetic acid solution (8.2.5) as food simulant so as to obtain food simulant test solution. Store it in a 0 C ~ 4 C refrigerator in the dark Determination of sample solution Pipet 20 ml of food simulant test solution (10.1) obtained by migration test in the 50 ml color comparison tube. Take another 2 ml of lead standard use solution (8.4.2) into the 50 ml color comparison tube. Add 20 ml of 4% acetic acid solution (8.2.5). Respectively add 1 ml of ammonium citrate solution (8.2.2), 3 ml of ammonia and 1 ml of potassium cyanide solution (8.2.1) into two color comparison tubes; add water to scale and well mix. Then respectively add 2 drops of sodium sulfide solution (8.2.4). Well mix. Place for 5 min. Taking white color as background, from the top or side, observe and compare the colors of simulated test solution and standard solution color. 11 Expression of analysis results When the sample color is darker than the color of standard solution, heavy Page 8 of 9