This standard specifies the determination method of aluminum in flour-based foods. This standard is applicable to the determination of aluminum in flour-based foods. The detection limit of this method is 0.5μg. GB/T 5009.182-2003 Determination of aluminum in flour-based foods GB/T5009.182-2003 Standard download decompression password: www.bzxz.net

ICS67.040
National Standard of the People's Republic of China
GB/T5009.182—2003
Partially replaces GB15202—1994
Deterrnination of aluminium in flour products
Deterrnination of aluminium in flour products2003-08-11 Issued
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on 2004-01-01
GB/T5009.182—2003
This standard replaces the test methods in Chapter 3 of GB15202—1994 Hygienic Standard for Limits of Aluminium in Flour Foods. This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Food Hygiene Supervision and Inspection Institute of the Ministry of Health. The main drafters of this standard are Su Dezhao, Zhu Lin and Wang Yongfang. 472wwW.bzxz.Net
1 Scope
Determination of aluminum in flour-based foods
This standard specifies the determination method of aluminum in flour-based foods. This standard is applicable to the determination of lead in flour-based foods. The detection limit of this method is 0.5μg.
2 Principle
GB/T5009.182—2003
After the sample is treated, the trivalent aluminum ions react with chrome azuro S and hexadecyltrimethylammonium bromide in acetic acid-sodium acetate buffer to form a blue ternary complex. The absorbance is measured at a wavelength of 640nm and compared with the standard for quantification. 3 Reagents
3.1 Nitric acid.
3.2 Chloric acid.
3.3 Sulfuric acid.
3.4 ​​Hydrochloric acid.
3.56mol/L Hydrochloric acid: Measure 50mL of hydrochloric acid (3.4) and dilute to 100mL with water. 3.61% (volume fraction) sulfuric acid solution.
3.7 Nitric acid-perchloric acid (5+1) mixture.
3.8 Acetic acid-sodium acetate solution: weigh 34g sodium acetate (NaAc·3HO) and dissolve it in 450mL water, add 2.6mL glacial acetic acid, adjust pH to 5.5, and dilute with water to 500mL.
3.90.5g/L Chromeazurol S solution: weigh 50mg Chromeazurol S, dissolve in water and dilute to 100mL3.100.2g/L hexadecyltrimethylammonium bromide solution: weigh 20mg hexadecyltrimethylammonium bromide, dissolve in water and dilute to 100mL. Heat to aid dissolution if necessary.
3.1110g/L ascorbic acid solution: weigh 1.0g ascorbic acid, dissolve in water and dilute to 100ml. Prepare immediately before use. 3.12 Aluminum standard stock solution: Accurately weigh 1.0000g of aluminum (purity 99.99%), add 50mL of 6mol/L hydrochloric acid solution, heat to dissolve, cool, transfer to a 1000mL volumetric flask, and dilute to scale with water. Each milliliter of this solution is equivalent to 1mg aluminum. 3.13 Aluminum standard working solution: Take 1.00mL of aluminum standard stock solution, place it in a 100mL volumetric flask, dilute to scale with water, then take 5.00mL from it and put it in a 50mL volumetric flask, dilute to scale with water. Each milliliter of this solution is equivalent to 1μg aluminum. 4 Instruments
4.1 Spectrophotometer.
4.2 Food grinder.
4.3 Electric hot plate.
5 Sample treatment
Crush the sample (excluding the filling part) and dry about 30g in an oven at 85℃ for 4h. Weigh 1.000g~2.000g and place it in a 100mL conical flask. Add several glass beads and 10mL~15mL nitric acid-perchloric acid (5+1) mixture. Cover with a glass cover and place overnight. Heat slowly on a hot plate until the digestion solution is colorless and transparent, and a large amount of pernitrogen acid smoke appears. Remove the conical flask, add 0.5mL sulfuric acid, without a glass cover, and place it on the hot plate to heat it appropriately to remove the perchloric acid. Add 10ml~15mL water and heat to 473
GB/T5009.182-2003
boiling. Remove and cool, and dilute to 50mL with water. If the sample dilution multiple is different, ensure that the sample solution contains 1% sulfuric acid. Make two reagent blanks at the same time.
6 Determination
Pipette 0.00.51.0, 2.03.0, 4.0, 6.0mL aluminum standard solution (equivalent to aluminum 00.5, 1.0, 2.0, 4.0, 6.0μg) and place them in 25mL colorimetric tubes respectively, and add 1mL 1% sulfuric acid solution to each tube in turn. Pipette 1.0mL digested sample solution and place it in a 25mL colorimetric tube. Add 8.0mL acetic acid-sodium acetate buffer and 1.0mL 10g/L ascorbic acid solution to the standard tube, sample tube, and reagent blank tube in turn, mix well, add 2.0mL 0.2g/L hexadecyl trimethylamine solution, mix well, and then add 2.0mL 0.5g/L chrome blue S solution, shake well, and dilute to the scale with water. After standing at room temperature for 20 minutes, use a 1cm colorimetric cup, adjust the zero point with a zero tube on the spectrophotometer, measure its absorbance at a wavelength of 640nm, and draw a standard curve for comparative quantification. 7 Result calculation
(Ar-A,)X1000
Where:
X-the content of aluminum in the sample, in milligrams per kilogram (mg/kg); A
Az-—the mass of aluminum in the reagent blank solution, in micrograms (μg); m-the mass of the sample, in grams (g);
Vi-the total volume of the sample digestion solution, in milliliters (mL); V, the volume of the sample digestion solution for determination, in milliliters (mL). The calculation result is expressed to one decimal place. 8 Precision
The absolute difference between two independent measurement results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 474
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