GB/T 5009.59-2003 Analytical methods for hygienic standards of polystyrene resins for food packaging

This standard specifies the determination method of the hygienic index of polystyrene resin used to make tableware, food containers or other food utensils. This standard is applicable to the determination of the hygienic index of polystyrene resin raw materials used to make tableware, food containers or other food utensils. GB/T 5009.59-2003 Analytical method of hygienic standard of polystyrene resin used in food packaging GB/T5009.59-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.59—2003
Replaces GB/T5009.59-1996
Method for analysis of hygienic standard of polystyreneresinforfood packaging
Promulgated on August 11, 2003
Ministry of Health of the People's Republic of China
Standardization Administration of China
Implemented on January 1, 2004
GB/T5009.59-2003
This standard replaces GB/T5009.59--1996 "Method for analysis of hygienic standard of polystyreneresinforfood packaging". Compared with GB/T5009.59-1996, this standard has been modified as follows: The structure of the original standard has been modified according to GB/T20001.4-2001 "Standard Preparation Rules Part 4: Chemical Analysis Methods".
This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Shanghai Municipal Health and Epidemic Prevention Station. This standard was first issued in 1985, revised for the first time in 1996, and this is the second revision. 468
1 Scope
Analysis methods for hygienic standards of polystyrene resins for food packaging
CB/T5009.59—2003
This standard specifies the determination methods for hygienic indicators of polystyrene resins used to make tableware, food containers or other food utensils. This standard is applicable to the determination of hygienic indicators of polystyrene resin raw materials used to make tableware, food containers or other food utensils. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest versions apply to this standard. GB/T5009.58-2003 Methods of analysis of hygienic standards for polyethylene resins for food packaging 3 Sampling method
Same as Chapter 2 of GB/T5009.58-2003. 4 Loss on drying
4.1 Principle
The mass lost by drying a sample at 100℃ for 3h is the loss on drying, which indicates the presence of volatile substances under this condition. 4.2 Analysis steps
Weigh 5.00g~10.00g of sample, spread it flat in a weighing bottle with a constant diameter of 40mm, dry it at 100℃ for 3h, cool it in a desiccator for 30min, weigh it, and the loss on drying shall not exceed 0.20g/100g. 4.3 Calculation, expression of results, precision
Same as 3.3 and 3.4 of GB/T5009.58-2003. 5 Volatile matter
5.1 Principle
When the sample is dried at 138℃～140℃ and the vacuum degree is 85.3kPa, the mass lost after drying for 2 hours minus the mass lost after drying is the volatile matter.
5.2 Reagents
Butanone.
5.3 Apparatus
5.3.1 Electric fan.
5.3.2 Vacuum drying oven.
5.3.3 Vacuum pump.
5.4 Analysis steps
After drying, weigh 2.00g~3.00g of sample between 20 mesh and 60 mesh in a 25mL beaker that is accurately weighed. Add 20mL of butanone and stir with a glass rod to make it completely dissolved. Use an electric fan to accelerate the evaporation of the solvent. When it becomes thick, move the beaker into a vacuum drying oven and place the beaker in a 45° sealed vacuum drying oven. Turn on the vacuum pump and maintain the temperature at 138℃~140℃ and the vacuum degree at 85.3kPa. After drying for 2h469
GB/T5009.59--2003
, move the beaker into a desiccator, cool for 30min, weigh it, calculate the volatile matter, and after deducting the loss on drying, it shall not exceed 1%. 5.5 Calculation of results
The calculation of volatile matter is shown in formula (1) and formula (2):
ml=m2x100
Wherein:
-the mass lost by the sample at 138℃～140℃, 85.3kPa, and drying for 2h, in grams per hundred grams (g/100g); X
-the mass of the sample plus the beaker, in grams (g); the mass of the sample plus the beaker after drying, in grams (g); the mass of the beaker, in grams (g).
X, = X -X2
Wherein: www.bzxz.net
X, — volatile matter, unit is gram per hundred gram (g/100g); X
— mass lost by a sample at 138℃~140℃, 85.3kPa, and drying for 2h, unit is gram per hundred gram (g/100g); X, — loss on drying of the sample, unit is gram per hundred gram (g/100g). The calculation result shall retain two significant figures.
5.6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of their arithmetic mean. 6 Volatile components such as styrene and ethylbenzene
6.1 Principle
The detection is carried out by using organic compounds to generate ionic compounds in a hydrogen flame. The peak height of the sample is compared with the peak height of the standard to calculate the equivalent content of the sample.
6.2 Reagents
6.2.1 Fixative: polyethylene glycol succinate. 6.2.2 Glaze 6201 red carrier.
Take 60-80 mesh 6201 red carrier and soak it in borax solution (20g/L) for 2 days and nights. The volume of the solution is about 10 times the volume of the carrier. Stir it 2-3 times during the soaking period. Filter the soaked carrier by suction, and dilute the mother liquor with water to 2 times the volume. Use the diluted mother liquor equivalent to the volume of the carrier to rinse under suction filtration. Dry the filtered carrier at 120℃, then burn it in a muffle furnace, keep it at 860℃ for 70min, and then keep it at 950℃ for 30min. After melting, rinse the carrier with boiling water for 4-5 times. The amount of water used each time is about 5 times the volume of the carrier. Do not stir too hard during immersion to avoid damaging the carrier particles and forming a new surface to affect the treatment effect. The washed support can be dried and sieved for use.
6.2.3 Internal standard: n-dodecane.
6.2.4 Carbon disulfide.
6.2.5 Styrene and ethylbenzene standard solution: Take a 100mL volumetric flask and put about 2/3 volume of carbon disulfide, accurately weighed as m. ; Add about 0.5g of styrene, accurately weighed as ml, and then add about 0.3g of ethylbenzene, accurately weighed as mz. as standard stock solution. The concentrations of styrene and ethylbenzene are calculated as shown in formula (3) and formula (4): Styrene concentration ca (g/mL) m = mo
Ethylbenzene concentration cs (g/mL) = mz = m
Take 1mL of standard stock solution in a 25mL volumetric flask, add 5mL of n-dodecane internal standard and then add carbon disulfide to the scale as standard working solution.
6.3 Instruments
6.3.1 Gas chromatograph: with FID detector. 6.3.2 Micro-syringe.
6.4 Analysis steps
6.4.1 Reference chromatographic conditions
GB/T5009.59—2003
6.4.1.1 Chromatographic column, stainless steel column, inner diameter 4mm, length 4m. Enameled 6201 red support of 60~80 mesh coated with 20% polyethylene glycol succinate.
6.4.1.2 Column temperature: 130℃, vaporization temperature: 200℃. 6.4.1.3 Carrier gas (nitrogen): pre-column pressure 1.8kg/cm2~2.0kg/cm; hydrogen flow rate: 50mL/min; air flow rate: 700mL/min6.5 Determination
Weigh 1.00g polystyrene, place in a 25mL volumetric flask, add carbon disulfide to dissolve, and dilute to scale. Accurately add 5μL of n-dodecane and shake thoroughly. After mixing evenly, take 0.5μL and inject into the chromatograph. After the chromatographic peak flows out, accurately measure the peak height of each component to be measured and n-dodecane, and calculate their ratio. According to the obtained peak height ratio, inject 0.Quantitative comparison of the components obtained by 5μL standard solution with the peak height ratio of n-dodecane,
Note 1: If there is no internal standard, the external standard method can be used, but the amount of each component should be as close to the actual content as possible to reduce the deviation. Note 2: When preparing the standard solution, different amounts of the main impurity components can be weighed, all calculated for 1g of polyvinyl chloride sample. See Figure 1 for the reference gas chromatogram.
Carbon disulfide;
2-Benzene,
3-Toluene,
4-n-dodecane (internal standard):
6.6 Result calculation
See formula (5):
Wherein:
5--Ethylbenzene:
6-Isopropylbenzene:
7-n-Propylbenzene;
8-Methylethylbenzene;
9-tert-Butylbenzene:
10-Styrene:
11--α-Methylstyrene;
12-3-Methylstyrene
X_EX(or c)×1 000
X——Content of volatile components of styrene or ethylbenzene, in grams per 100 grams (g/100g); F——Ratio of peak height of sample to internal standard; F——Ratio of peak height of standard to internal standard; (5)
GB/T5009.59-2003
cA——Concentration of styrene, in grams per milliliter (g/mL); CB
Concentration of ethylbenzene, in grams per milliliter (g/mL): mass of sample, in grams (g).
The calculation result shall retain two significant figures.
6.7 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 15% of the arithmetic mean. n-Hexane extract
According to Chapter 5 of GB/T5009.58-2003. 472
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