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HG2682—1995
Chemical Industry Standard of the People's Republic of China
Food Additives
Sodium Hydrosulfite (Hydrosulfite)
1 Subject Content and Scope of Application
HG2682—1995
This standard specifies the technical requirements, test methods, inspection rules, and marking, packaging, transportation, and storage of the food additive sodium hydrosulfite. This standard applies to the food additive sodium hydrosulfite (also known as hydrosulfite) prepared by the reaction of zinc powder or sodium formate with sulfur dioxide. This product is mainly used in the food industry and also in the pharmaceutical industry. Molecular formula: Na2S,04
Relative molecular mass: 174.11 (according to the international relative atomic mass in 1991) 2 Reference standards
GB190 Dangerous goods packaging mark
GB191 Pictorial mark for packaging storage and transportation
GB/T601 Preparation of standard solution for titration analysis (volumetric analysis) of chemical reagents GB/T602 Preparation of standard solution for determination of impurities of chemical reagents GB/T603 Preparation of preparations and products used in test methods of chemical reagents GB/T619 Sampling and acceptance rules for chemical reagents GB/T6682 Specifications and test methods for water used in analytical laboratories GB8450 Determination of arsenic in food additives 3 Technical requirements
3.1 Appearance: white crystalline powder
3.2 Food additives
Sodium dithionite should meet the requirements of the following table. Item
Sodium dithionite (Na2SOz) content, %>
Clarity
Heavy metal (Pb) content, %
Content,
Disodium ethylenediaminetetraacetate content
Formate (HCHO) content, %
4 Test method
The reagents and water used in this standard, unless otherwise specified, refer to analytical reagents and grade 3 water specified in GB/T6680. The standard titration solutions, impurity standard solutions, preparations and products used in the test, unless otherwise specified, are prepared according to the methods specified in GB/T601, GB/T602 and GB/T603. 4.1 Identification test
Approved by the Ministry of Chemical Industry of the People's Republic of China on April 5, 1995 and implemented on January 1, 1996
HG2682-1995
4.1.1 Reagents and materials
4.1.1.1 Copper sulfate (GB/T665): 50g/L solution; 4.1.1.2 Potassium permanganate (GB/T643): 3.5g/L solution; 4.1.1.3 Sodium hydroxide (GB/T629): 150g/L solution; 4.1.1.4 Potassium pyroantimonate solution;
Preparation: Weigh 2g potassium pyroantimonate (accurate to 0.01g), add 100mL water, boil for about 5min, cool quickly, add 10mL sodium hydroxide solution, let stand for 24h, and filter. 4.1.2 Identification method
4.1.2.1 Sodium dithionite
Take 10mL of 10g/L test solution and add 2mL of copper sulfate solution, and it will turn gray-black. b.
Take 10mL of 10g//L test solution and add 1mL of potassium permanganate solution, and the color of the solution will disappear immediately.
4.1.2.2 Sodium salt
a. Dip a glass rod into 10g/L test solution and burn it on an alcohol lamp to turn yellow. b. Take an appropriate amount of 50g/L test solution and add potassium pyroantimonate solution to generate a white crystalline precipitate (rubbing the inner wall of the test tube with a glass rod can accelerate the formation of the precipitate). 4.2 Determination of sodium dithionite content
4.2.1 Method summary
Sodium dithionite reacts with neutral formaldehyde to generate sodium bisulfite formaldehyde and sodium bisulphite formaldehyde. Sodium bisulphite formaldehyde reacts with iodine. The content of sodium dithionite is determined based on the consumption of iodine standard titration solution.
4.2.2 Reagents and materials
4.2.2.1 Hydrochloric acid (GB/T622): 1+11 solution; 4.2.2.2 Soluble starch: 10g/L solution; 4.2.2.3 Neutral formaldehyde solution: 1+1 solution; Preparation: Take 100mL formaldehyde solution (GB/T685) and 100mL water, place in a 400mL beaker, stir evenly, add a few drops of 10g/L phenolphthalein (GB/T10729) indicator solution, neutralize with 100g/L sodium hydroxide (GB/T629) solution until the solution is slightly red, and then adjust with hydrochloric acid solution until the slightly red color just fades. 4.2.2.4 Iodine (GB/T675): standard titration solution with c(1/2I2) of about 0.1mol/L. 4.2.3 Analysis steps
Weigh about 1g of sample (accurate to 0.0002g), place it in a beaker pre-filled with 20mL of neutral formaldehyde solution, stir until completely dissolved, carefully transfer to a 250mL volumetric flask, dilute to the mark with water, and shake well. Transfer 25.00mL of the solution to a 250mL conical flask, add 4mL of hydrochloric acid solution, titrate with iodine standard titration solution, add 3mL of starch solution when approaching the end point, and continue titrating until the solution turns light blue. The end point is when the color does not disappear within 30s, and a blank test is performed at the same time. 4.2.4 Expression of analysis results
The sodium dithionite (Na2S2O4) content (X) expressed as mass percentage is calculated according to formula (1): (V-Vo)cX0.04353
43.53 (V-Vo) c
（1）
Approved by the Ministry of Chemical Industry of the People's Republic of China on April 5, 1995, and implemented on January 1, 1996
HG2682-1995
Wherein: V is the volume of the standard iodine titration solution consumed by the titration of the test solution, mL; V is the volume of the standard iodine titration solution consumed by the titration of the blank solution, mL; C is the actual concentration of the standard iodine titration solution, mol/L; m is the mass of the sample, g;
0.04353 is the mass of sodium dithionite in grams equivalent to 1.00mL of the standard iodine titration solution [c (1/212=1.000mol/L). 4.2.5 Allowable Difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.3%.
4.3 Determination of clarity
4.3.1 Summary of method
The content of insoluble matter in sodium dithionite can be simply determined by observing the dissolution of sodium dithionite in neutral formaldehyde solution.
4.3.2 Reagents and materials
4.3.2.1 Neutral formaldehyde solution: 1+1 solution, preparation method is the same as 4.2.2.3; 4.3.2.2 Nitric acid (GB/T626): 1+2 solution; 4.3.2.3 Dextrin (C6H10Os)·XH2O]: 20g/L solution; 4.3.2.4 Silver nitrate (GB/T670): 20g/L solution; 4.3.2.5 Hydrochloric acid (GB/T622): c(HCI)=0.10mol/L standard solution; 4.3.2.6 Chlorine standard solution: 1mL solution contains 0.01mgCl; Preparation: Use a pipette to transfer 14.1mL of hydrochloric acid standard solution, place it in a 50mL volumetric flask, dilute to the scale, and shake well. 1mL of this solution contains 1mL of Cl; use a pipette to transfer 1mL of this solution, place it in a 100mL volumetric flask, dilute to the mark, and shake well. This solution is prepared just before use.
4.3.3 Analysis steps
4.3.3.1 Preparation of standard turbidity solution (slightly turbid) Use a pipette to transfer 6mL of chlorine standard solution, place it in a 25mL colorimetric tube, add water to 20mL, add 1mL of nitric acid solution, 0.2mL of dextrin solution and 1mL of silver nitrate solution, shake well, and place it away from direct sunlight for 15min.
4.3.3.2 Determination
Weigh about 0.5g of the sample (accurate to 0.001g), place it in a 25mL colorimetric tube pre-filled with 10mL of neutral formaldehyde solution, and place it for 5min after it is completely dissolved. Its turbidity shall not be greater than that shown in the standard turbidity solution.
4.4 Determination of heavy metal content
4.4.1 Method summary
In weakly acidic solution, heavy metal ions and divalent sulfide ions generate colored sulfide precipitates. When the heavy metal content is low, a stable dark suspension is generated, which can be used for visual colorimetric determination of heavy metals. 4.4.2 Reagents and materials
4.4.2.1 Hydrochloric acid (GB/T622);
4.4.2.2 Acetic acid (GB/T676): 1+19 solution; 4.4.2.3 Sodium sulfide (HG/T3905) solution; Preparation: Weigh 5g sodium sulfide (accurate to 0.01g), dissolve it with a mixture of 10mL water and 30mL glycerol (Glycerin) (GB/T687); or weigh 5g sodium hydroxide (GB/T629), dissolve it with a mixture of 30mL water and 90mL glycerol. Cool half of the solution while passing hydrogen sulfide to saturate it, then add the remaining half and mix, fill the vial under light protection, cover and seal for storage. Valid for three months after preparation.
4.4.2.4 Lead standard solution: 1mL solution contains 0.010mgPb. Prepare it when it is used. Use a pipette to transfer 10mL of the lead standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute it to the scale with water, and shake it well. /
4.4.3 Analysis steps
4.4.3.1 Preparation of test solution
Weigh about 10g of sample (accurate to 0.01g), place in a 300mL beaker, add 60mL of hot water to dissolve, add 10mL of hydrochloric acid and evaporate to dryness on an adjustable electric stove. Carefully increase the heat until the sulfur spontaneously ignites. Add 30mL of hot water and 10mL of hydrochloric acid to the residue, and evaporate to dryness on an adjustable electric stove. Dissolve the residue in water, dilute to 40mL with water, filter, put the filtrate and washing liquid into a 50mL volumetric flask, dilute to scale with water, and shake well. This is solution A. Use a pipette to transfer 10mL of solution A, place in a 50mL colorimetric tube, add 2mL of acetic acid solution, dilute to scale with water, and shake well. 4.4.3.2 Preparation of standard colorimetric solution
Pipette 2.00mL of lead standard solution into a 50mL colorimetric tube, add 2mL of acetic acid solution, dilute to the mark with water, and shake well.
4.4.3.3 Determination
Add 2 drops of sodium sulfide solution to each of the test solution and the standard colorimetric solution. After standing for 5 minutes, the color of the test solution shall not be darker than that of the standard colorimetric solution. 4.5 Determination of zinc content
4.5.1 Summary of the method
In an acidic medium, zinc ions react with potassium ferrocyanide solution to form a white precipitate, which can be used for the visual colorimetric determination of zinc.
4.5.2 Reagents and materials
4.5.2.1 Ammonia water (GB/T631): 2+3 solution; 4.5.2.2 Hydrochloric acid (GB/T622): 1+3 solution: 4.5.2.3 Potassium ferrocyanide (GB/T1273): 100g/L solution: Preparation: Weigh 10g potassium ferrocyanide (accurate to 0.01g) and dilute with water to 100mL. This solution is prepared before use.
4.5.2.4 Zinc standard solution: 1mL solution contains 0.10mgZn. 4.5.3 Analysis steps
Pipette 5mL of solution A (4.4.3.1) and place it in a 50mL beaker, add 0.1mL of ammonia solution, filter, place the filtrate in a 25mL colorimetric tube, dilute to 20mL with water, add 5mL of hydrochloric acid solution, shake well, add 0.1mL of potassium ferrohydride solution, and place for 15min. Its turbidity shall not be greater than that of the standard turbidity solution. The standard turbidity solution is 4mL of zinc standard solution pipetted with a pipette, placed in a 25mL colorimetric tube, starting from "dilute to 20mL with water", and treated in the same way as the test solution. 4.6 Determination of arsenic content
4.6.1 Summary of the method
Same as Article 2.1 of GB8450.
4.6.2 Reagents and materials
Arsenic standard solution: 1mL of solution contains 0.001mgAs. Prepare immediately before use. Use a pipette to transfer 10mL of the standard arsenic solution prepared according to GB/T602, place it in a 1000mL volumetric flask, dilute it to the mark with water, and shake it well.
Approved by the Ministry of Chemical Industry of the People's Republic of China on April 5, 1995, and implemented on January 1, 1996
HG2682-1995
Others are the same as Article 1.2.3, 1.2.7~1.2.10 and 2.2.3 of GB8450. 4.6.3 Instruments and equipment
Same as Article 2.3 of GB8450.
4.6.4 Analysis steps
Weigh about 2.5g of the sample (accurate to 0.01g), place it in a 100mL beaker, add water to dissolve it, transfer it to a 25ml volumetric flask, dilute it to the mark with water, and shake it well. Transfer 5.00mL to a 100mL beaker, add 1mL sulfuric acid, evaporate and concentrate until about 2mL, transfer all to the arsenic test bottle, add 4mL hydrochloric acid, and the following operations are carried out according to Article 2.4 of GB8450 starting from "add water to 30mL**." The color of the arsenic spot on the mercuric bromide test paper shall not be darker than the standard.
The standard is to take 1.50mL of the arsenic standard solution, place it in the arsenic test bottle, add 5mL hydrochloric acid, start from "add water to 30mL", and treat it in the same way as the sample. 4.7 Determination of disodium ethylenediaminetetraacetic acid content 4.7.1 Summary of the method
Arsenious acid reduces chromate ions to chromium ions, and chromium ions and disodium ethylenediaminetetraacetic acid form a purple complex, which can be used for the test of disodium ethylenediaminetetraacetic acid. 4.7.2 Reagents and materials
4.7.2.1 Acetic acid (GB/T676);
4.7.2.2 Potassium chromate (HG/T3918): 5g/L solution; 4.7.2.3 Sodium hydroxide (GB/T629): 25g/L solution; 4.7.2.4 Arsenous acid (GB/T673): 10g/L solution. Preparation: Weigh 1g arsenous acid (arsenic trioxide), add 30mL sodium hydroxide solution, heat to dissolve, cool, and slowly add acetic acid to 100mL. 4.7.3 Analysis steps
Weigh 0.5g sample (accurate to 0.001g), place in a test tube, add 5mL water to dissolve, add 2mL: potassium chromate solution, 2mL arsenous acid solution, heat on a water bath for 2min until no purple color appears. 4.8 Determination of formate content
4.8.1 Summary of the method
In a hydrochloric acid medium, magnesium powder reduces formate to formaldehyde, which reacts specifically with chromic acid and can be used for the visual colorimetric determination of formate. 4.8.2 Reagents and materialsbZxz.net
4.8.2.1 Magnesium powder;
4.8.2.2 Sulfuric acid (GB/T625);
4.8.2.3 Hydrochloric acid (GB/T622: 1+1 solution); 4.8.2.4 Chromic acid (C1oHNa2S20O·2H20): 10g/L solution; Preparation: Weigh 0.5g chromic acid, add 50mL sulfuric acid, shake, centrifuge, use the upper clear liquid, and prepare before use.
4.8.2.5 Dilute formaldehyde standard solution: 1mL solution contains 0.002mgHCH0. Preparation: Use a pipette to take 10mL of GB/T6 02Put the prepared formaldehyde solution in a 100mL volumetric flask, dilute to the mark with water, and shake well. 1mL of this solution contains 0.1mgHCHCO. Take 2.00mL of the above solution, put it in a 100mL volumetric flask, dilute to the mark with water, and shake well. This solution is prepared for immediate use.
4.8.3 Analysis steps
Weigh 0.1g of the sample (accurate to 0.001g), put it in a 100mL volumetric flask, dilute to the mark with water, and shake well. Use a pipette to take 10mL of the solution, put it in a beaker, add 5mL of hydrochloric acid solution, and then two 1996-01-01 implementation
HG2682-1995
Add a small amount of magnesium powder at a time, add to about 0.3g, and when bubbles are almost invisible, cover the surface with blood, leave for 2 hours, transfer 1.00mL of solution into a 10mL colorimetric tube, add 2mL sulfuric acid and 0.5mL chromic acid, and heat in a boiling water bath for 10 minutes. Its color shall not be darker than the standard colorimetric solution. The standard colorimetric solution is to transfer 1.0mL of dilute formaldehyde solution, start from "add 5mL hydrochloric acid solution", and treat the sample in the same way at the same time.
5 Inspection rules
5.1 Food additive sodium dithionite should be produced by the manufacturer The quality inspection department of the factory shall conduct inspections in accordance with the provisions of this standard. The manufacturer shall ensure that all sodium dithionite solution, a food additive, meets the requirements of this standard. Each batch of sodium dithionite solution, a food additive, shall be accompanied by a quality certificate. The contents include: manufacturer name, output, product name, net weight, batch number or production date, food hygiene license number, production license number, certification that product quality meets this standard and this standard number. 5.2 The user has the right to inspect and accept the sodium dithionite product, a food additive, received in accordance with the provisions of this standard.
5.3 Each batch of materials shall be inspected in batches. 5.4 According to GB619 Section 3.The number of sampling units shall be determined according to the provisions of Article 4, and random sampling shall be used for sampling, with a sampling volume of not less than 200g. After sampling, the collected samples shall be quickly mixed and divided into two clean, dry wide-mouth bottles with ground stoppers and sealed. Labels shall be affixed to the bottles, indicating: manufacturer name, product name, batch number, sampling date and name of the sampler. One bottle is used for inspection and the other bottle is kept for three months for future reference. 5.5 If one indicator of the inspection result does not meet the requirements of this standard, re-sampling shall be carried out from twice the amount of packaging for verification. If even one of the inspection results does not meet the requirements of this standard, the entire batch of products cannot be accepted.
5.6 When the supply and demand parties have objections to the product quality, they shall be handled in accordance with the provisions of the "Product Quality Law of the People's Republic of China".
6 Marking, packaging, transportation and storage
6.1 The packaging bottles of food additive sodium dithionite should be firmly labeled, including the words "food additive", manufacturer name, factory address, product name, food hygiene license number, production license number, trademark, net weight, batch number or production date and this standard number. The packaging boxes should be firmly marked, including the words "food additive", manufacturer name, product name, production license number, trademark, net weight, assembly quantity per box, gross weight, batch number or production date, shelf life and the mark 10 "flammable items when wet" specified in GB190 and the mark 7 "heat-averse" specified in GB191. 6.2 Food additive sodium dithionite is available in two forms: inner packaging and outer packaging. The inner packaging is a wide-mouth brown bottle with a specification of 500g per bottle. The inner layer is tightly plugged with a plastic plug, the outer layer is tightened with a bakelite cap, and the seal is sealed with a plastic heat shrink sleeve; the outer packaging is a wooden box, with 20 bottles in a box, the box board thickness is more than 1cm, and 16 bars are added around the wooden box. The box should be wrapped with iron waist or iron wire or iron sheet for corners. The gaps in the box are filled with soft materials.
6.3 Food additive sodium dithionite should be covered during transportation, and the packaging box should not be inverted, collided, prevented from moisture, rain, and avoid direct sunlight. It is forbidden to mix with toxic and harmful substances. 6.4 Food additive sodium dithionite should be stored in a ventilated, dry, roofed warehouse, avoid direct sunlight, away from heat sources, and must not come into contact with water or water vapor. It must not be mixed with oxidants or other flammables. It is forbidden to store it in the same warehouse with toxic and harmful substances. Cover each bottle immediately after use and store it properly.
6.5 The shelf life of food additive sodium dithionite is half a year from the date of production. Approved by the Ministry of Chemical Industry of the People's Republic of China on April 15, 1995, and implemented on January 1, 1996
HG2682-1995
Additional Notes
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Shanghai Sulfuric Acid Plant, Dazhong Chemical Plant of Wuxi Chemical Group Co., Ltd., and Shantou Hydrocarbon Powder Plant. The main drafters of this standard are Shi Jie, Zong Kejian, Lu Yongxiang, and Zheng Jianrong. This standard is equivalent to the "Japanese Food Additives Code" (1986 Edition) "Hydrocarbon Powder". From the date of implementation of this standard, the original national standard GB1647-1979 "Food Additives Safe Powder" shall be invalidated
Approved by the Ministry of Chemical Industry of the People's Republic of China on April 5, 1995 and implemented on January 1, 1996
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