Some standard content:
National Standard of the People's Republic of China
Food Additives
Sodium Alginate
GB 1976 - 80
-A polysaccharide carbohydrate extracted from kelp by adding alkali and processed and refined. This standard applies to the main component of brown algae plants-
sodium alginate, which can be added to food as a thickener, etc. Indicative formula: (C, H, O, Na) n
Structural formula:
Molecular weight:
Structural unit: Theoretical value 198.11, average true value 222.00. Macromolecule: 32,000-250,000
I. Technical requirements
1. Appearance: white or light yellow powder.
2. Sodium alginate shall meet the following requirements:
Water insoluble matter (on dry basis), %
Transparency
Viscosity, centipoise
Loss on drying, %
Sulfated ash, %
Heavy metal (on Pb), %
Lead (Pb), %
Arsenic (As), %
This product shall not be produced with harmful preservatives such as formaldehyde or other substances that may increase viscosity. State Administration of Standardization
Ministry of Health of the People's Republic of China
State General Administration of Fisheries
Combination Regulations
October 1, 1980
Luda City Health and Epidemic Prevention Station
Luda Fisheries Chemical Plant
GB 1976 --80
II. Acceptance Rules
3. This product should be inspected by the technical inspection department of the manufacturer. The manufacturer should ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory should be accompanied by a quality certificate. 4 The user can verify the quality of the received products according to the inspection rules and test methods specified in this standard to check whether their indicators meet the requirements of this standard.
5. The weight of each batch shall not exceed the output of each shift of the manufacturer. 6. Sampling method: Samples should be selected from 10% of the number of packages in each batch. In the case of small batches, no less than 3 packages should be selected. From the selected packages, use sampling needles and other sampling tools to extend into 3/4 of each package and take out no less than 100 grams of samples. The total sample weight of each batch shall not be less than 2 kilograms. The selected samples are quickly mixed and evenly divided into about 500 grams by quartering method. They are placed in clean, dry wide-mouth bottles with ground stoppers. Labels are attached to the bottles, indicating the manufacturer name, product name, batch number and sampling date, and sent to the laboratory for analysis. 7. If one of the indicators during the inspection does not meet the requirements of this standard, samples should be selected from twice the amount of packaging for re-inspection. If the result of the product re-inspection does not meet the requirements of this standard even if only one indicator does not meet the requirements of this standard, the entire batch cannot be accepted. III. Test methods
8. Identification
(1) Reagents and solutions
Calcium chloride (HGB3208--60): analytical grade, 5% solution: Sulfuric acid (GB625-77): analytical grade, 10% solution. Add 57 ml of sulfuric acid to 100 ml of water, cool and dilute to 1000 ml with water:
Naphthalene resorcinol: analytical grade, 1% ethanol solution; Hydrochloric acid (GB622-77): analytical grade;
Isopropyl ether: analytical grade:
Uranyl cobalt acetate solution: Take 8 g of uranyl acetate, add 6 g of glacial acetic acid and appropriate amount of water to make 100 ml, take 40 g of cobalt acetate, add 6 g of glacial acetic acid and appropriate amount of distilled water to make 100 ml, heat the two liquids to about 75°C to dissolve, mix and cool, and place at 20°C for 2 hours to allow excess salts to precipitate, filter with dry filter paper to obtain the solution. (2) Identification procedures
a. Take 5 ml of the sample (1:100) aqueous solution, add 1 ml of 5% calcium chloride solution, and a colloidal precipitate will be generated immediately. b. Take 10 ml of the sample (1:100) aqueous solution, add 1 ml of 10% sulfuric acid solution, and a colloidal precipitate will be generated. C. Take 5 mg of the sample in a test tube, add 5 ml of distilled water, 1 ml of a newly prepared 1% resorcinol ethanol solution, and 5 ml of hydrochloric acid to boil, and boil slightly for 3 minutes, cool to 15°C, wash the contents with 5 ml of distilled water into a 30 ml separatory funnel, and extract with 15 ml of isopropyl ether. The purple color of the extract should be darker than that of the reagent blank extract. d. Take 5 mg of the sample and ash it, dissolve it in hydrochloric acid and filter it, add uranyl cobalt acetate solution to the filtrate, stir it for several minutes, and a golden precipitate will gradually precipitate.
9. Determination of pH value
Take the sample and prepare it into a 1% aqueous solution, and measure it with pH test paper or acidity meter. 10. Determination of water-insoluble matter
Weigh about 0.5 g of the sample (accurate to 0.0002 g), add 200 ml of distilled water to a 500 ml beaker, cover the watch glass, heat and boil for 1 hour, stir frequently, filter under reduced pressure with a G3 vertical melting filter that has been dried and weighed to constant weight while hot, and wash the filter thoroughly with hot distilled water, and dry at 105°C to constant weight. The water-insoluble matter X (%) is calculated as follows: Xi =-Gl=G2- ×100
Where: G,—
-Total weight of filter and insoluble matter, g:
-Weight of filter, g
G weight of sample, g.
11. Determination of transparency
(1) Reagents and solutions
GB 1976--80
Sulfuric acid (GB62577): analytical grade, 0.01N solution, prepared and calibrated according to GB601-77; 95% ethanol (GB679-65): analytical grade; Hydrochloric acid (GB622--77): analytical grade, 10% solution, add distilled water to 23.5 ml hydrochloric acid to 100 ml; Monochlorinated sodium (GB652-78): analytical grade, 12% solution. (2) Determination procedure
Weigh 0.5 g of the sample (accurate to 0.01 g), add 90 ml of boiling distilled water to dissolve, cool and add distilled water to 100 ml, pour this solution into a colorimetric tube (250×25 mm), place the colorimetric tube on a white paper with 15 black lines 1 mm apart, take another colorimetric tube (300×15 mm) and put it in the upper tube, move the inner tube up and down until the black lines drawn on the white paper can be clearly seen, repeat this operation three times, measure the distance between the bottoms of the two colorimetric tubes, and this distance must not be smaller than the distance measured by the standard solution. At the same time, prepare a standard solution, take 8 ml of 0.01N sulfuric acid solution, add 1 ml of 10% hydrochloric acid solution, 5 ml of ethanol, add distilled water to 50 ml, add 2 ml of 12% barium chloride solution, mix well, let it stand for 10 minutes, and operate according to the above method. 12. Determination of viscosity
(1) Instrument
EMILA rotational viscometer;
Constant temperature water bath.
(2) Determination procedure
Weigh the sample in grams, the weight of which can be made into 100 ml of sodium alginate solution with a concentration of 1%, and calculate it according to the absolute relative mass of the sample. The calculation method is as follows;
Where, weigh the sample amount, grams;
D—loss on drying, %.
Weigh the sample (accurate to 0.01 g), add 25 ml of cold distilled water, stir, then add 70 ml of boiling distilled water, stir for several minutes, cool and add distilled water to 100 ml, leave at room temperature for 4 hours to make a uniform glue solution, select the corresponding rotor and place it in the measuring tank, and carefully pour the glue solution to the lower edge of the cone surface, and the rotor is completely immersed in the liquid, put the measuring tank on the rack, hang the hook on the driver, adjust the zero point, turn on the constant temperature device, keep the measured temperature within the range of 20 ± 0.1℃, start the switch, keep the pointer on the scale plate stable, and read the degree. If the reading is less than 10, it is necessary to replace the second larger rotor. The viscosity X, (centipoise) is calculated as follows: Xz pointer reading × rotor multiple
13. Measurement of drying loss
(1) Instrument
Aluminum box: diameter 45-50 mm, height 25 mm. (2) Determination procedure
Weigh an appropriate amount of sample (accurate to 0.0002 g) into an aluminum box that has been dried and weighed to constant weight. The sample thickness is about 510 mm. Spread it evenly, open the cover and dry it at 105℃ for 4 hours until constant weight. Drying loss X. (%) is calculated as follows: X,-G=Gz×100
Where: G,—-weight of aluminum box and sample before drying, g; G2——weight of aluminum box and sample after drying, g; G—weight of sample, g.
14. Determination of sulfated ash
(1) Reagents and solutions
Sulfuric acid (GB625-77): analytical grade. GB 1976-80
(2) Determination procedure
Weigh 2 grams of sample (accurate to 0.0002 grams) from the porcelain blood that has been burned to constant weight, add 1.5 milliliters of sulfuric acid, wet and carbonize the sample, place it in a high-temperature furnace and burn it at 450-550℃, let it cool, then add 1 milliliter of sulfuric acid and burn it until it is completely ashed, let it cool in a desiccator, and weigh it. Sulfate ash X, (%) is calculated as follows: X
Where; G-ash content and porcelain dish weight, grams,
G--porcelain III weight, grams;
G-sample weight, grams,
- Loss on drying, %.
15. Determination of heavy metals
(1) ReagentswwW.bzxz.Net
G(1- D)
Phenolic acid (HGB3039-59) indicator solution: 1% ethanol solution, nitric acid (GB626-78): analytical grade;
Sodium hydroxide (GB629-77): analytical grade, 10% solution, hydrochloric acid (GB622--77): analytical grade, 10% solution; glacial acetic acid (GB676-78): analytical grade, 30% solution, saturated hydrogen sulfide water: prepared before use;
Lead standard solution: prepared according to GB602--77 and diluted 10 times before use, containing 0.01 mg lead per ml. (2) Determination procedure
Take the residue for ash determination and add 5 ml nitric acid, evaporate to dryness on a water bath, cool and dissolve in distilled water, add 1 drop of phenol indicator solution, adjust the alkalinity with 10% sodium hydroxide solution, adjust with 10% hydrochloric acid until the red color just fades, filter into 50 ml base, wash the residue with distilled water several times, and dilute to 25 ml, add 0.5 ml 30% acetic acid solution, dilute to 40 ml with distilled water, and make tube A. Take another 50 ml Nessler colorimetric tube, add 4 ml lead standard solution and 0.5 ml 30% acetic acid solution, dilute to 40 ml with distilled water, and make tube B.
Add 10 ml saturated hydrogen sulfide water to each tube A and B, shake well, and place in a dark place for 10 minutes for colorimetric comparison. The color of tube A is not darker than that of tube B.
16. Determination of lead
(1) Reagents and solutions
Lead standard solution: prepared according to GB602-77 and diluted 100 times for use, each milliliter contains 0.001 mg of lead; Ammonium citrate: analytical grade, 10% solution, take 50 grams of ammonium citrate and dissolve it in 100 milliliters of distilled water, add 2 drops of phenol red indicator solution, add ammonia water until it turns slightly red, use dithiol chloroform solution to extract the lead in several batches, discard the chloroform layer, and continue to extract the solution with chloroform until the extract is green. Wash away the residual dithiol with fluoroform until the chloroform layer is colorless, and add lead-free water to 500 milliliters. Hydroxylamine hydrochloride (HG3-967-76): analytically pure, 20% solution, take 100 grams of hydroxylamine hydrochloride and dissolve it in 200 ml of distilled water, remove the lead according to the preparation method of ammonium citrate solution, then add hydrochloric acid to adjust to acidity, and finally add lead-free water to 500 ml, potassium cyanide: analytically pure, 10% solution;
ammonia water (GB63177): analytically pure, 1:1 solution; cresol red (HGB3084-59): analytically pure, 0.1% ethanol solution, disulfide (H GB3343-60): analytical grade, weigh 50 mg of disulfide and add 100 ml of chloroform, use this as the stock solution, take 1.5 ml of this solution before use, dilute it to 100 ml with chloroform, the transmittance of this solution is about 60% when measured at a wavelength of 530 mμ by a spectrophotometer; Chlorine (GB682-78): analytical grade;
Sulfuric acid (GB625-77): analytical grade;
30% hydrogen peroxide (HG3-1082-77): analytical grade. 467
GB1976-80
(2) Determination procedure
Weigh 5 g of the sample (accurate to 0.1 g) into a small beaker, then transfer it to a 250 ml Kjeldahl flask. Wash the beaker with a small amount of distilled water, combine the washing liquid in the Kjeldahl flask, add 10 ml of 30% hydrogen peroxide, heat slowly, wait until the effect slows down, let cool, slowly add 3 ml of sulfuric acid from the wall of the flask and heat. If the solution is brown-black, add 2 to 3 ml of 30% hydrogen peroxide each time, continue heating until white smoke is generated and the solution is clear, colorless or slightly yellow, let cool, transfer it to a 50 ml volumetric flask, wash the Kjeldahl flask several times with a small amount of distilled water, combine the washing liquid in the volumetric flask, add distilled water to the scale after cooling, and at the same time make a reagent blank. Take 10 ml of the reagent blank solution in a 50 ml stoppered colorimetric tube, add 3 ml of the lead standard solution, add distilled water to 20 ml, add 5 ml of ammonium citrate solution, 1 ml of hydroxylamine hydrochloride solution, 2 drops of phenol red indicator solution, adjust to a slightly red color with ammonia solution, add 2 ml of potassium fluoride solution, add 2 ml of dithiochloroform solution, shake for 1 minute, and let stand to separate. Take 10 ml of the sample solution (equivalent to 1 gram of sample), add 10 ml of distilled water, and then follow the above method from "add 5 ml of ammonium citrate solution...".
The red hue of the chloroform layer of the sample solution shall not be darker than the red hue of the chloroform layer of the reagent blank solution after adding the standard solution. 17. Determination of arsenic
(1) Instrumentation: According to the instrumentation of the "Arsenic Salt Test Method" of the Pharmacopoeia of the People's Republic of China, 1977 edition. (2) Reagents and solutions
Hydrochloric acid (GB622-77): analytical grade;
Potassium iodide (GB1272-77): analytical grade, 15% solution; Sulfuric acid (GB625-77): analytical grade;
Stannous chloride (GB638-78): analytical grade, 40% hydrochloric acid solution; Metallic zinc (HGB307359): analytical grade; Lead acetate cotton: soaked in 5% lead acetate solution 1. Degreased cotton: squeeze dry, dry below 100℃, and store in a sealed bottle. 2. Mercuric bromide test paper: cut dense smooth filter paper into small pieces, immerse in 5% mercuric bromide acetic acid solution, take out and place in a cool place to dry, and store in a sealed brown bottle. 3. Arsenic standard solution: prepare according to GB602--77, dilute 100 times for use, each milliliter is equivalent to 0.001 mg of arsenic. 4. Ammonia water (GB631--77): 1:1 solution. (3) Determination procedures
Take 10 ml of the sample digestion solution under the lead test item in Article 16 (equivalent to 1 gram of sample), add distilled water to a total volume of 23 ml, transfer to a conical flask, add 4.5 ml of hydrochloric acid, 5 ml of 15% potassium iodide solution and 5 drops of 10% acidic stannous chloride solution, shake and place for 10 minutes, add 2 grams of metal-free zinc, immediately seal the glass tube filled with lead acetate cotton and mercuric bromide test paper, and place it in a dark place at 25-30℃ for 1 hour. The color of the mercuric bromide test paper should not be darker than the standard. The standard is to take 2 ml of arsenic standard solution and add it to 10 ml of reagent blank solution and treat it in the same way as the sample solution. IV. Packaging, marking, storage and transportation
18. Sodium alginate should be packaged in clean and firm cartons or lined with polyethylene plastic bags and covered with two layers of kraft paper bags. The seal must be tight. The net weight of each box (bag) is 25 kg.
19. The boxes (bags) should be firmly marked with: manufacturer name, product name, batch number, production date, net weight, and the words "food additive".
20. Each batch of sodium alginate shipped out of the factory should be accompanied by a quality certificate, which includes: manufacturer name, product name, batch number, production date and inspection date, number of pieces, weight and product quality, etc. 21. Sodium alginate should not be mixed with harmful substances during storage and transportation, and should be kept dry and clean, avoid sunlight, rain and heat, and should be stored at least 100 mm above the ground to avoid moisture. 22. Storage period: Under the required storage conditions, the quality should remain stable within nine months. 468001 mg lead; ammonium citrate: analytical grade, 10% solution, take 50 g ammonium citrate and dissolve it in 100 ml distilled water, add 2 drops of phenol red indicator solution, add ammonia water until it turns slightly red, use dithiol chloroform solution to extract the lead in batches, discard the chloroform layer, continue to extract the solution with chloroform until the extract is green, wash away the residual dithiol with fluoroform until the chloroform layer is colorless, add lead-free water to 500 ml. Hydroxylamine hydrochloride (HG3-967-76): analytically pure, 20% solution, take 100 grams of hydroxylamine hydrochloride and dissolve it in 200 ml of distilled water, remove the lead according to the preparation method of ammonium citrate solution, then add hydrochloric acid to adjust to acidity, and finally add lead-free water to 500 ml, potassium cyanide: analytically pure, 10% solution;
ammonia water (GB63177): analytically pure, 1:1 solution; cresol red (HGB3084-59): analytically pure, 0.1% ethanol solution, disulfide (H GB3343-60): analytical grade, weigh 50 mg of disulfide and add 100 ml of chloroform, use this as the stock solution, take 1.5 ml of this solution before use, dilute it to 100 ml with chloroform, the transmittance of this solution is about 60% when measured at a wavelength of 530 mμ by a spectrophotometer; Chlorine (GB682-78): analytical grade;
Sulfuric acid (GB625-77): analytical grade;
30% hydrogen peroxide (HG3-1082-77): analytical grade. 467
GB1976-80
(2) Determination procedure
Weigh 5 g of the sample (accurate to 0.1 g) into a small beaker, then transfer it to a 250 ml Kjeldahl flask. Wash the beaker with a small amount of distilled water, combine the washing liquid in the Kjeldahl flask, add 10 ml of 30% hydrogen peroxide, heat slowly, wait until the effect slows down, let cool, slowly add 3 ml of sulfuric acid from the wall of the flask and heat. If the solution is brown-black, add 2 to 3 ml of 30% hydrogen peroxide each time, continue heating until white smoke is generated and the solution is clear, colorless or slightly yellow, let cool, transfer it to a 50 ml volumetric flask, wash the Kjeldahl flask several times with a small amount of distilled water, combine the washing liquid in the volumetric flask, add distilled water to the scale after cooling, and at the same time make a reagent blank. Take 10 ml of the reagent blank solution in a 50 ml stoppered colorimetric tube, add 3 ml of the lead standard solution, add distilled water to 20 ml, add 5 ml of ammonium citrate solution, 1 ml of hydroxylamine hydrochloride solution, 2 drops of phenol red indicator solution, adjust to a slightly red color with ammonia solution, add 2 ml of potassium fluoride solution, add 2 ml of dithiochloroform solution, shake for 1 minute, and let stand to separate. Take 10 ml of the sample solution (equivalent to 1 gram of sample), add 10 ml of distilled water, and then follow the above method from "add 5 ml of ammonium citrate solution...".
The red hue of the chloroform layer of the sample solution shall not be darker than the red hue of the chloroform layer of the reagent blank solution after adding the standard solution. 17. Determination of arsenic
(1) Instrumentation: According to the instrumentation of the "Arsenic Salt Test Method" of the Pharmacopoeia of the People's Republic of China, 1977 edition. (2) Reagents and solutions
Hydrochloric acid (GB622-77): analytical grade;
Potassium iodide (GB1272-77): analytical grade, 15% solution; Sulfuric acid (GB625-77): analytical grade;
Stannous chloride (GB638-78): analytical grade, 40% hydrochloric acid solution; Metallic zinc (HGB307359): analytical grade; Lead acetate cotton: soaked in 5% lead acetate solution 1. Degreased cotton: squeeze dry, dry below 100℃, and store in a sealed bottle. 2. Mercuric bromide test paper: cut dense smooth filter paper into small pieces, immerse in 5% mercuric bromide acetic acid solution, take out and place in a cool place to dry, and store in a sealed brown bottle. 3. Arsenic standard solution: prepare according to GB602--77, dilute 100 times for use, each milliliter is equivalent to 0.001 mg of arsenic. 4. Ammonia water (GB631--77): 1:1 solution. (3) Determination procedures
Take 10 ml of the sample digestion solution under the lead test item in Article 16 (equivalent to 1 gram of sample), add distilled water to a total volume of 23 ml, transfer to a conical flask, add 4.5 ml of hydrochloric acid, 5 ml of 15% potassium iodide solution and 5 drops of 10% acidic stannous chloride solution, shake and place for 10 minutes, add 2 grams of metal-free zinc, immediately seal the glass tube filled with lead acetate cotton and mercuric bromide test paper, and place it in a dark place at 25-30℃ for 1 hour. The color of the mercuric bromide test paper should not be darker than the standard. The standard is to take 2 ml of arsenic standard solution and add it to 10 ml of reagent blank solution and treat it in the same way as the sample solution. IV. Packaging, marking, storage and transportation
18. Sodium alginate should be packaged in clean and firm cartons or lined with polyethylene plastic bags and covered with two layers of kraft paper bags. The seal must be tight. The net weight of each box (bag) is 25 kg.
19. The boxes (bags) should be firmly marked with: manufacturer name, product name, batch number, production date, net weight, and the words "food additive".
20. Each batch of sodium alginate shipped out of the factory should be accompanied by a quality certificate, which includes: manufacturer name, product name, batch number, production date and inspection date, number of pieces, weight and product quality, etc. 21. Sodium alginate should not be mixed with harmful substances during storage and transportation, and should be kept dry and clean, avoid sunlight, rain and heat, and should be stored at least 100 mm above the ground to avoid moisture. 22. Storage period: Under the required storage conditions, the quality should remain stable within nine months. 468001 mg lead; ammonium citrate: analytical grade, 10% solution, take 50 g ammonium citrate and dissolve it in 100 ml distilled water, add 2 drops of phenol red indicator solution, add ammonia water until it turns slightly red, use dithiol chloroform solution to extract the lead in batches, discard the chloroform layer, and continue to extract the solution with chloroform until the extract is green. Wash away the residual dithiol with fluoroform until the chloroform layer is colorless, and add lead-free water to 500 ml. Hydroxylamine hydrochloride (HG3-967-76): analytically pure, 20% solution, take 100 grams of hydroxylamine hydrochloride and dissolve it in 200 ml of distilled water, remove the lead according to the preparation method of ammonium citrate solution, then add hydrochloric acid to adjust to acidity, and finally add lead-free water to 500 ml, potassium cyanide: analytically pure, 10% solution;
ammonia water (GB63177): analytically pure, 1:1 solution; cresol red (HGB3084-59): analytically pure, 0.1% ethanol solution, disulfide (H GB3343-60): analytical grade, weigh 50 mg of disulfide and add 100 ml of chloroform, use this as the stock solution, take 1.5 ml of this solution before use, dilute it to 100 ml with chloroform, the transmittance of this solution is about 60% when measured at a wavelength of 530 mμ by a spectrophotometer; Chlorine (GB682-78): analytical grade;
Sulfuric acid (GB625-77): analytical grade;
30% hydrogen peroxide (HG3-1082-77): analytical grade. 467
GB1976-80
(2) Determination procedure
Weigh 5 g of the sample (accurate to 0.1 g) into a small beaker, then transfer it to a 250 ml Kjeldahl flask. Wash the beaker with a small amount of distilled water, combine the washing liquid in the Kjeldahl flask, add 10 ml of 30% hydrogen peroxide, heat slowly, wait until the effect slows down, let cool, slowly add 3 ml of sulfuric acid from the wall of the flask and heat. If the solution is brown-black, add 2 to 3 ml of 30% hydrogen peroxide each time, continue heating until white smoke is generated and the solution is clear, colorless or slightly yellow, let cool, transfer it to a 50 ml volumetric flask, wash the Kjeldahl flask several times with a small amount of distilled water, combine the washing liquid in the volumetric flask, add distilled water to the scale after cooling, and at the same time make a reagent blank. Take 10 ml of the reagent blank solution in a 50 ml stoppered colorimetric tube, add 3 ml of the lead standard solution, add distilled water to 20 ml, add 5 ml of ammonium citrate solution, 1 ml of hydroxylamine hydrochloride solution, 2 drops of phenol red indicator solution, adjust to a slightly red color with ammonia solution, add 2 ml of potassium fluoride solution, add 2 ml of dithiochloroform solution, shake for 1 minute, and let stand to separate. Take 10 ml of the sample solution (equivalent to 1 gram of sample), add 10 ml of distilled water, and then follow the above method from "add 5 ml of ammonium citrate solution...".
The red hue of the chloroform layer of the sample solution shall not be darker than the red hue of the chloroform layer of the reagent blank solution after adding the standard solution. 17. Determination of arsenic
(1) Instrumentation: According to the instrumentation of the "Arsenic Salt Test Method" of the Pharmacopoeia of the People's Republic of China, 1977 edition. (2) Reagents and solutions
Hydrochloric acid (GB622-77): analytical grade;
Potassium iodide (GB1272-77): analytical grade, 15% solution; Sulfuric acid (GB625-77): analytical grade;
Stannous chloride (GB638-78): analytical grade, 40% hydrochloric acid solution; Metallic zinc (HGB307359): analytical grade; Lead acetate cotton: soaked in 5% lead acetate solution 1. Degreased cotton: squeeze dry, dry below 100℃, and store in a sealed bottle. 2. Mercuric bromide test paper: cut dense smooth filter paper into small pieces, immerse in 5% mercuric bromide acetic acid solution, take out and place in a cool place to dry, and store in a sealed brown bottle. 3. Arsenic standard solution: prepare according to GB602--77, dilute 100 times for use, each milliliter is equivalent to 0.001 mg of arsenic. 4. Ammonia water (GB631--77): 1:1 solution. (3) Determination procedures
Take 10 ml of the sample digestion solution under the lead test item in Article 16 (equivalent to 1 gram of sample), add distilled water to a total volume of 23 ml, transfer to a conical flask, add 4.5 ml of hydrochloric acid, 5 ml of 15% potassium iodide solution and 5 drops of 10% acidic stannous chloride solution, shake and place for 10 minutes, add 2 grams of metal-free zinc, immediately seal the glass tube filled with lead acetate cotton and mercuric bromide test paper, and place it in a dark place at 25-30℃ for 1 hour. The color of the mercuric bromide test paper should not be darker than the standard. The standard is to take 2 ml of arsenic standard solution and add it to 10 ml of reagent blank solution and treat it in the same way as the sample solution. IV. Packaging, marking, storage and transportation
18. Sodium alginate should be packaged in clean and firm cartons or lined with polyethylene plastic bags and covered with two layers of kraft paper bags. The seal must be tight. The net weight of each box (bag) is 25 kg.
19. The boxes (bags) should be firmly marked with: manufacturer name, product name, batch number, production date, net weight, and the words "food additive".
20. Each batch of sodium alginate shipped out of the factory should be accompanied by a quality certificate, which includes: manufacturer name, product name, batch number, production date and inspection date, number of pieces, weight and product quality, etc. 21. Sodium alginate should not be mixed with harmful substances during storage and transportation, and should be kept dry and clean, avoid sunlight, rain and heat, and should be stored at least 100 mm above the ground to avoid moisture. 22. Storage period: Under the required storage conditions, the quality should remain stable within nine months. 4685 ml of hydrochloric acid, 5 ml of 15% potassium iodide solution and 5 drops of 10% acidic stannous chloride solution, shake and place for 10 minutes, add 2 grams of metal-free zinc, immediately seal the glass tube filled with lead acetate cotton and mercuric bromide test paper, place it in a dark place at 25-30°C for 1 hour, and the color of the mercuric bromide test paper should not be darker than the standard. The standard is to take 2 ml of arsenic standard solution and add it to 10 ml of reagent blank solution and treat it in the same way as the sample solution. IV. Packaging, marking, storage and transportation
18. Sodium alginate should be packaged in clean and firm cartons or lined with polyethylene plastic bags and two layers of kraft paper bags. The seal must be tight, and the net weight of each box (bag) is 25 kg.
19. The box (bag) should be firmly marked with: manufacturer name, product name, batch number, production date, net weight, and the words food additive.
20. Each batch of sodium alginate shipped out of the factory should be accompanied by a quality certificate, which includes: manufacturer name, product name, batch number, production date and inspection date, number of pieces, weight and product quality, etc. 21. Sodium alginate should not be mixed with harmful substances during storage and transportation, and should be kept dry and clean, avoid sunlight, rain and heat, and should be stored at least 100 mm above the ground to avoid moisture. 22. Storage period: Under the required storage conditions, the quality should remain stable within nine months. 4685 ml of hydrochloric acid, 5 ml of 15% potassium iodide solution and 5 drops of 10% acidic stannous chloride solution, shake and place for 10 minutes, add 2 grams of metal-free zinc, immediately seal the glass tube filled with lead acetate cotton and mercuric bromide test paper, place it in a dark place at 25-30°C for 1 hour, and the color of the mercuric bromide test paper should not be darker than the standard. The standard is to take 2 ml of arsenic standard solution and add it to 10 ml of reagent blank solution and treat it in the same way as the sample solution. IV. Packaging, marking, storage and transportation
18. Sodium alginate should be packaged in clean and firm cartons or lined with polyethylene plastic bags and two layers of kraft paper bags. The seal must be tight, and the net weight of each box (bag) is 25 kg.
19. The box (bag) should be firmly marked with: manufacturer name, product name, batch number, production date, net weight, and the words food additive.
20. Each batch of sodium alginate shipped out of the factory should be accompanied by a quality certificate, which includes: manufacturer name, product name, batch number, production date and inspection date, number of pieces, weight and product quality, etc. 21. Sodium alginate should not be mixed with harmful substances during storage and transportation, and should be kept dry and clean, avoid sunlight, rain and heat, and should be stored at least 100 mm above the ground to avoid moisture. 22. Storage period: Under the required storage conditions, the quality should remain stable within nine months. 468
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