This standard specifies the limit test method for heavy metals in food additives. This standard is applicable to the limit test of heavy metals in food additives. GB/T 5009.74-2003 Limit test of heavy metals in food additives GB/T5009.74-2003 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
CB/T5009.74-—2003
代4s1--853
Method for limit test uf heavy metals in fond 2003-08-11 issued
Ministry of Health of the People's Republic of China
China National Standardization Administration
2004-01-01 implementation
(H/T5009.74-2003)
This standard is based on the relevant determination method issued by the Joint Expert Committee of Food Additives of the United Nations Agriculture and Rural Development Organization and the World Health Organization (FAO/WHO), and replaces the (H/1451-19872) Metal Limit Test Method for Food Additives. This standard has the following main changes compared with (H/T8451-197): the Chinese name of the standard has been changed, and the Chinese name has been changed to Metal Limit Test for Food Additives; according to (KT23001.42001≤Standard Writing Rules Section 1 ：Beijing Analytical Method" revised the structure of the original standard
This standard was proposed and exported by the Ministry of Health of the People's Republic of China. This standard was developed by Huang Qixing, director of the Epidemic Prevention Station of Jiangsu Medical University Health Center. The original standard was issued 2009 years ago, and this is the first time to be revised. 1 Scope
Metal limit test in food additives
This standard specifies the limit test method for metals in food additives. This standard is applicable to the limit test of heavy metals in food additives. 2 Principle
GB/I5009.74-2003wwW.bzxz.Net
Under weakly acidic pH 3-4 conditions, the heavy metal ions in the sample are mixed with hydrogen sulfide to produce brown color, and the sample is compared with the standard lead standard treated by the above method to do the quality test.
3 Reagents
3. 1 Nitric acid
3.3 Salt fermentation:
3.3.16mol/t. Hydrochloric acid: Take 5ml. Salt. Dilute with water to 1iKJnul.a3.3.211mol/L hydrochloric acid: Take 8.3mL salt, dilute with water to 100ml.3.4 Ammonia
3.4.16ttio/L water tray 40mL ammonia, dilute to 100mJ.3.4.21ml/1. Hydrogen water, take 5.7ml. Hydrogen water, dilute with water to 100mL. 3.5pH3 .5 acetic acid, weigh 25.0g of it and put it into 25ml of water, add 45mL of 5mol/L hydrochloric acid, adjust the concentration to .5 with dilute hydrochloric acid or dilute nitrogen, dilute with water to 3.6, and indicate 17.
3. Saturate the environment with oxygenated water, pass the oxygen gas into water without iodine dioxide: until the concentration is positive (this solution is prepared before freezing). 3. Lead standard solution: weigh 1598g of high-purity lead, dissolve it in 10ml of 1.1 tablet of lead aldehyde, transfer it to a 50mL volumetric flask, and dilute with water until it is empty. This fusible wire is equivalent to 1.0 mL. Before use, dilute it with water to 100% of the original volume to make it 1 mL. When 10 g of lead is used, 3.91% phytic acid: take 1 mL of phytic acid and add water to dilute it to 1 mL. 2 instruments need to be replaced with 0%-20% head soaked for more than 2 hours, rinsed repeatedly with tap water, and rinsed clean after rinsing. 5 mL paper tube, 5 sample treatment: 1. Generally, the sample can be directly measured according to the first step. The color of the blood vessel is similar to that of the heart tube. The bottom light has been treated for a period of time. The organic sample must be eliminated by the T method, and then 5.1.6.2, 6.4 are performed. .1 The "treatment method" of the sample not specified in the standard text can be used in violation of the method specified in the standard text. 5.2 The "treatment method" of the sample with selected properties can be used in violation of the method specified in the standard text. 5.2.1 Dissolve the sample, brown> 0.0, add 10mL 1mT acid in a 250mL Kjeldahl flask or a small flask without lubrication, place the sample (. After the level has been destroyed, heat it, wait for the level and the precision control, add m, comb it, and heat it again. The liquid in the filter cabinet becomes brown, and no acid is added (if necessary, pay attention to prevent drying during the dyeing process). Continue heating until the organic matter is completely decomposed. The final liquid should be a light grey color. After cooling, add 54L of water and boil to remove the remaining sulphuric acid until smoke is produced. Cool twice, add 50mL of sulphuric acid to a flask or three-layer flask with water, add the washed liquid to the flask, add water to the scale, and moisten evenly: every 10 mL of sulphuric acid is equivalent to 1/2 of the liquid. Add 0.2 mL of sulphuric acid to the sample and slowly flow it. Digest according to the above method, the sample is not digested by wet method. Weigh more than 1 mL of sulphuric acid and place it in a flask or three-layer flask. Moisten it evenly: every 10 mL of sulphuric acid is equivalent to 1/2 of the liquid. Digest according to the above method, the sample is not digested by wet method. Then, after a small fire, add 2m2 of aldehyde and 1 drop of clotting acid, heat slightly, transfer to two wet bottles until white smoke appears, add 2ml/min of salt to moisten the mixture, and slowly dry it with water to evaporate the mixture. Remove the remaining salt solution and add 1 drop of water to dissolve it, and heat it for 2 seconds. Transfer the remaining solution to a volumetric bottle, and then transfer the remaining solution to a volumetric bottle. Use a spoon to wash the filtrate with a water-based paint. The solution is equivalent to 1.1ml of the sample. While the sample is being treated, take another sample and perform the reagent test in the above method. The determination result is that the content of calcium is equivalent to the specified limit of gold (not less than 1 mg/L)! If the sample is present in the Nassler colorimetric tube, take an equal amount of reagent as the sample solution), add water to 25mL, add 1 drop of the indicator solution, adjust with 60.1% dilute acid or 1l/10 diluted buffer solution to make it red, then take a Nessler colorimetric tube that matches the tube: add 0.1-1ml (or appropriate amount) sample solution, add 2rl of water, add 1 drop of 3% sieved hydrochloric acid to make it red (make it cloudy with 1ml/10 water), add 5ml of 4.5% acetate and set aside. 6.3: Take the same colorimetric tube as tube A, add the same sample as tube B, then add the same standard solution as tube A, add water to 25% 1:1, adjust the indicator solution to 1:1 with dilute nitrogen water (1ml/1. or 1mnl/1.) with sieved hydrochloric acid (0.5ml/1. or 1mnl/1.), and mix until the pH is 10 (red is visible). Rinse with 3% acetic acid to 5ml, and set aside. 6.4 Add 10mL of the newly prepared saturated solution to each tube, and add 50ml of water. Mark the mark. After 5 minutes, observe under the color background, the color of tube C should not be darker than the color of tube A, and the color of tube C should be equal to or darker than the color of tube A.
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