GB/T 5009.62-2003 Analytical methods for hygienic standards of ceramic tableware containers

This standard specifies the analysis methods for various hygienic indicators of various ceramic tableware, containers and food utensils that are in direct contact with food. This standard is applicable to the analysis of various hygienic indicators of various ceramic tableware, containers and food utensils that are in direct contact with food. GB/T 5009.62-2003 Analysis methods for hygienic standards of ceramic tableware containers GB/T5009.62-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.62—2003
Replaces GB/T5009.62--1996
Method for analysis of hygienic standard of ceramics for food containers
Promulgated on August 11, 2003
Ministry of Health of the People's Republic of China
China National Standardization Administration
Implementation on January 1, 2004
GB/T5009.62—2003
This standard replaces GB/T5009.62—1996 "Method for analysis of hygienic standard of ceramics for food containers". Compared with GB/T5009.621996, the main modifications of this standard are 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 Foshan Municipal Health and Epidemic Prevention Station of Guangdong Province. This standard was first issued in 1985 and revised for the first time in 1996. This is the second revision. 484
1 Scope
Analysis methods for hygienic standards of ceramic tableware and containers GB/T5009.62-2003
This standard specifies the analysis methods for various hygienic indicators of various ceramic tableware, containers and food utensils that are in direct contact with food.
This standard is applicable to the analysis of various hygienic indicators of various ceramic tableware, containers and food utensils that are in direct contact with food. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties reaching an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version shall apply to this standard. GB/T5009.12—2003 Determination of lead in food GB13121 Hygienic standard for ceramic tableware containers
3 Sampling method
Select samples from each batch of glazed and decorated products. Generally, the number of small batches shall not be less than 6, and the product name, batch number and sampling date shall be indicated. If the sample is small, increase the sampling volume according to the inspection needs. Half of the sample is used for testing, and the other half is kept for two months for arbitration analysis. 4 Appearance inspection and sensory indicators
The shape of the vessel is correct, the inner wall surface is smooth, the glaze is evenly drawn, and the decoration does not fall off, which should comply with the provisions of GB13121. 5 Soaking conditions
5.1 Reagents
Acetic acid (4%).
5.2 Analysis steps
First, wipe the surface of the sample with a soft cloth soaked in a slightly alkaline detergent, then wash it with tap water, rinse it with water, and dry it for later use. Add boiling acetic acid (4%) to 1 cm from the upper edge (if there are flowers on the edge, soak the flower surface), cover it with a glass, and soak it at room temperature not lower than 20℃ for 24 hours. The soaking liquid volume of flat vessels that cannot hold liquids is calculated by adding 2mL for every square centimeter of the surface area of ​​vessel III. That is, divide vessel III into several simple geometric shapes and calculate the total area. If the whole organ is placed in the soaking solution, the volume of soaking solution added should be multiplied by 2 according to the calculation of two sides. 6 Lead
6.1 Flame atomic absorption spectrometry
6.1.1 Principle, reagents, instruments
Same as Chapter 14, Chapter 15, and Chapter 16 of GB/T5009.12-2003. 6.1.2 Analysis steps
According to Chapter 5 of GB/T5009.12-2003, the acetic acid (4%) soaking solution can be directly injected into the atomic absorption spectrophotometer for analysis. When the sensitivity is insufficient, a certain amount of soaking solution can be taken and evaporated, concentrated, and fixed to volume before measurement. 485
GB/T5009.62-—2003
6.1.3 Calculation of results
See formula (1):
Wherein:
mx1000
Vx1000
X is the lead content in the immersion solution, in milligrams per liter (mg/L); m is the mass of lead in the immersion solution taken during the determination, in micrograms (μg); V is the volume of the immersion solution taken during the determination, in milliliters (mL). The calculation result shall retain two significant figures.
6.1.4 Precision
Same as Chapter 19 of GB/T5009.12-2003. 6.2 Dithiol Method
6.2.1 Principle, Reagents, Instruments
Same as Chapter 20, Chapter 21, and Chapter 22 of GB/T5009.12-2003. 6.2.2 Analysis Steps
Measure 10.0mL of soaking solution and dilute it accurately to 100mL with water. Take two 25mL stoppered colorimetric tubes, add 10.0mL of soaking diluent to one tube and 7.0mL of lead standard solution (equivalent to 7μg lead) and 1ml of acetic acid (4%) to the other tube, and then add water to 10mL. Add 1.0mL of ammonium citrate solution, 0.5mL of hydroxylamine hydrochloride solution, and 1 drop of phenol red indicator solution to each tube, mix well, add ammonia water until it turns red, add 1 more drop, and then add 1.0mL of potassium cyanide solution and shake well. Then add 5.0mL of dithiol-chloroform solution to each tube, vibrate for 2 minutes, and then stand for colorimetry. The red color of the sample tube should not be darker than that of the standard tube. Otherwise, use a 1cm colorimetric cup, adjust the zero point with trichloromethane, and measure the absorbance at a wavelength of 510nm for comparative quantification. 6.2.3 Calculation of results
See formula (2):
Where:
A,XmX1000
A,×V×1000
X-the content of lead in the immersion solution, in milligrams per liter (mg/L); the absorbance of the lead standard solution;
the mass of the lead standard solution, in micrograms (ug);-the absorbance of the immersion solution;
V is the volume of the immersion solution, in milliliters (mL). Expression of results: Report less than or greater than 7mg/L. 7.1 Atomic absorption spectrometry
7.1.1 Principle
After the cadmium ions in the immersion solution are introduced into the atomic absorption instrument and atomized, they absorb the 228.8nm resonance line. The absorption amount is proportional to the cadmium content in the test solution and is quantitatively compared with the standard series. 7.1.2 Reagents
7.1.2.1 Cadmium standard solution: Accurately weigh 0.1142g cadmium oxide, add 4mL glacial acetic acid, slowly heat to dissolve, cool, transfer to a 100mL volumetric flask, and dilute to the scale with water. This solution is equivalent to 1.00mg cadmium per milliliter. 7.1.2.2 Cadmium standard working solution: Take 1.0mL cadmium standard solution, place it in a 100mL volumetric flask, and dilute to the scale with acetic acid (4%). This solution is equivalent to 10.0μg cadmium per milliliter.
7.1.3 Instrument
Atomic absorption spectrophotometer.
7.1.4: Analysis steps
GB/T5009.622003
7.1.4.1 Preparation of standard curve: Pipette 0, 0.50, 1.00, 3.00, 5.00, 7.00, 10.00mL of standard solution, place in 100mL volumetric flasks, dilute to scale with acetic acid (4%), mix well, each milliliter is equivalent to 0, 0.05, 0.10, 0.30, 0.50, 0.70, 1.00g of cadmium, adjust the instrument to the best conditions for determination, and draw a standard curve according to the peak height of the corresponding concentration. 7.1.4.2 Sample determination
Adjust the determination instrument to the best conditions, then directly introduce the sample immersion solution or its dilution into the flame for determination, and compare with the standard curve for quantification.
Measurement conditions: wavelength 228.8nm, lamp current 7.5mA, slit 0.2nm, air flow 7.5L/min, acetylene gas flow 1.0L/min, background correction with chlorine lamp.
7.1.5 Result calculation
See formula (3):
Wherein:
mx1000
Vx1000
X is the content of cadmium in the sample immersion solution, in milligrams per liter (mg/L); m
is the mass of cadmium in the sample immersion solution taken during the measurement, in micrograms (μg); V is the volume of the sample immersion solution taken during the measurement (if a diluted solution is taken, it should be multiplied by the dilution multiple), in milliliters (mL). The calculation result should retain two significant figures.
7.1.6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 15% of the arithmetic mean. 7.2 Dithiol Method
7.2.1 Principle
Cadmium ions react with dithiol to form a red complex under alkaline conditions, which can be extracted and compared with organic solvents such as chloroform. Adding potassium sodium tartrate solution and controlling the pH value can mask the interference of other metal ions. 7.2.2 Reagents
7.2.2.1 Chloroform
7.2.2.2 Sodium hydroxide-potassium cyanide solution (A): Weigh 400g sodium hydroxide and 10g potassium cyanide, dissolve in water, and dilute to 1000mL. Sodium hydroxide-potassium cyanide solution (B): Weigh 400g sodium hydroxide and 0.5g potassium cyanide, dissolve in water, and dilute to 1000mL. 7.2.2.3
7.2.2.4 Dithiol-triazine solution (0.1g/L). Dithiol-chloroform solution (0.02 g/1). 7.2.2.5
7.2.2.6 Potassium sodium tartrate solution (250 g/L). Hydroxylamine hydrochloride solution (200 g/L).
7.2.2.8 Tartaric acid solution (20 g/L): Store in refrigerator. 7.2.2.9 Cadmium standard working solution: Same as 7.1.2.2. 7.2.3 Instrument
Visible spectrophotometer.
7.2.4 Analysis stepsWww.bzxZ.net
Take two 125 ml separating funnels, add 0.5 mL of cadmium standard working solution (equivalent to 5 μg) and 9.5 mL of acetic acid (4%) to one, and add 10 mL of sample soaking solution to the other. Add 1 mL of sodium potassium tartrate solution, 5 mL of sodium hydroxide-potassium cyanide solution (A) and 1 mL of hydroxylamine hydrochloride solution to the separatory funnels respectively. After adding each reagent, shake them to make them stick. Add 15 mL of dithiol-chloroform solution (0.1 g/L) and shake for 2 minutes (this step should be done quickly). Take another set of separatory funnels, add 25 mL of tartaric acid solution to each, put the dithiol-chloroform solution in the first set of separatory funnels into them, wash the first set of separatory funnels with 10 mL of chloroform, and also put the chloroform washing solution into the second set of separatory funnels. Shake the second set of separatory funnels for 2 minutes, discard the dithiol-chloroform solution, and then add 6 mL of chloroform to each, and discard the chloroform layer after shaking. Add 1.0mL of hydroxylamine hydrochloride solution, 15.0mL of dithiol-triazine solution (0.02g/L) and 5mL of sodium hydroxide-potassium cyanide solution (B) to the aqueous solution in the separatory funnel, and shake immediately for 2min. Wipe the inner wall of the lower tube of the separatory funnel dry, insert a little cotton wool to filter out water droplets, put the dithiol-triazine solution into a 25mL colorimetric tube with a stopper, and perform colorimetry. The red color of the sample tube shall not be darker than that of the standard tube. Otherwise, use a 3cm colorimetric cup, adjust the zero point with chloroform, measure the absorbance at a wavelength of 518nm, and perform quantitative analysis.
7.2.5 Calculation of results
Same as 6.2.3.
7.2.6 Precision
Same as 6.1.4.
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