Some standard content:
Record number: 7477-2000
HG3669-2000
This standard is formulated based on the actual production and use in my country. This standard sets up six items: effective chlorine dioxide content, density, pH value, arsenic content, heavy metal content and methanol content. In the test method, heavy metals and arsenic are determined by the general method of food additive determination in my country; the effective chlorine dioxide content is determined by the iodine method after hydrochloric acid activation; the pH value adopts the general rule for pH determination of chemical reagents; the density determination adopts the general rule for density determination of chemical products; the methanol content is determined by the fuchsin visual colorimetry method in the national standard "Analysis Method for Hygienic Standards of Distilled Liquor and Blended Liquor". Appendix A of this standard is a prompt appendix.
This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Inorganic Chemical Branch of the National Chemical Standardization Technical Committee and the Food Hygiene Supervision and Inspection Institute of the Ministry of Health. Drafting units of this standard: Tianjin Chemical Research and Design Institute of the Ministry of Chemical Industry, Huate Enterprise Corporation of Shandong University of Technology, Shanghai Future Enterprise Co., Ltd., and Shanghai Jiyuan Technology Co., Ltd. The main drafters of this standard are Yao Jinjuan, Liu Jingmin, Xi Songnian, Fang Xiumin and Shi Laishun. The Inorganic Chemical Branch of the National Technical Committee for the Promotion of Chemical Standards is responsible for the interpretation of this standard. 319
1 Scope
Chemical Industry Standard of the People's Republic of China
Food Additives
Stable Chlorine Dioxide Solution
Food additive--
Stable chlorine dioxide solutionHG 3669—2000
This standard specifies the requirements, test methods, inspection rules and signs, labels, packaging, transportation and storage of food additive stable chlorine dioxide solution.
This standard applies to stable chlorine dioxide solution obtained by absorbing chlorine dioxide gas by carbonate, a food additive. This product is used as a preservative and food processing aid in food processing. This product must be activated with hydrochloric acid, a food additive, when used. 2 Cited standards
The clauses contained in the following standards constitute the clauses of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB191-1990 Pictorial markings for packaging, storage and transportation
Chemical reagents
GB/T 601---1988
GB/T 602-- 1988
GB/T 603—1988
GB/T 4472-1984
GB/T 6678—1986
GB/T 6682-1992
GB/T 8450—1987
GB/T 8451—1987
GB/T 9724--1988
3 Requirements
Chemical reagents
Preparation of standard solutions for titration analysis (volumetric analysis) Preparation of standard solutions for impurity determination
Preparation of preparations and products used in chemical reagent test methods General rules for determination of density and relative density of chemical products General rules for sampling of chemical products
Specifications and test methods for water used in analytical laboratories (neqISO3696:1987) Determination method for monuments in food additives
Test method for limits of heavy metals in food additives General rules for determination of pH value of chemical reagents
3.1 Appearance: colorless or slightly yellow transparent liquid, free of suspended matter 3.2 Food additives Steady-state chlorine dioxide solution shall meet the requirements of Table 1. Table 1 Requirements
Available chlorine dioxide (CIO,) content, %Density (20℃), g/cm
Arsenic (As) content, %
Heavy metal (Pb) content, %
Methanol content, g/100mL
Approved by the State Administration of Petroleum and Chemical Industry on June 5, 2000320
1.020~~1.060
8.2~ 9. 2
Implementation on March 1, 2001
4 Test method
HG 3669—2000
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 3 water specified in GB/T6682. The standard titration solution, impurity standard solution, preparation and product used in the test shall be prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603 unless otherwise specified.
Safety Tips: The strong acid and alkali used in this standard are corrosive. Users should be careful when operating to avoid splashing on the skin. If splashed on the skin, wash with water immediately. In severe cases, treatment should be given immediately. 4.1 Identification Test
4.1.1 Identification of Sodium
Dip a platinum wire in hydrochloric acid solution and burn it on a flame until it is colorless. Then dip a small amount of the test solution in the flame and burn it. The flame will be bright yellow. 4.1.2 Identification of Carbonate
Add 100g/L calcium chloride solution to the test solution to produce a white precipitate. The precipitate dissolves in hydrochloric acid. 4.1.3 Identification of Chlorine Dioxide
Add (1+2) hydrochloric acid solution to the test solution to produce yellow gas, while the liquid is yellow. 4.2 Determination of effective fluorine dioxide content
4.2.1 Method summary
The sample is activated with hydrochloric acid, and the released effective chlorine dioxide is absorbed by potassium iodide-sulfuric acid solution and titrated with sodium thiosulfate standard titration solution.
4.2.2 Reagents and materials
Potassium iodide.
Sulfuric acid solution: 1+1.
4. 2. 2. 2
4.2.2.3 Hydrochloric acid solution: 1+4.
4.2.2.4 Standard sodium thiosulfate titration solution; c(Naz S,O:) is about 0.1 mol/L. 4.2.2.5 Starch indicator solution: 10g/L, with a useful life of two weeks. 4.2.3 Instruments and equipment
The effective fluorine dioxide determination device is shown in Figure 1.
1—Flask; 2—Separatory funnel; 3—Glass liquid sealed tube; 4—Triangular flask Figure 1 Apparatus for determination of effective chlorine dioxide
4.2.4 Analysis steps
Install the instrument according to Figure 1.
HG 3669—2000
Weigh about 2g of sample (accurate to 0.0002g) and place it in a 25ml flask. Add 10ml of hydrochloric acid solution to the separatory funnel. Add 4g of potassium iodide to the triangular flask, dissolve it with 100ml of water, and then add 3ml of sulfuric acid solution. Add water seal to the glass liquid sealed tube. Connect the flask and the triangular flask with a catheter and keep it sealed. Put the hydrochloric acid solution in the separatory funnel into the ground-mouth flask and close the stopcock. Slowly heat the flask, and the generated chlorine dioxide gas is completely absorbed in the triangular flask through the catheter (until there is no yellow-green gas in the catheter). Remove the catheter of the flask, stop heating, pour the water seal liquid in the glass liquid seal tube into the flask, titrate the absorption liquid in the flask with sodium thiosulfate standard titration solution until it turns light yellow, add 1ml starch indicator, and continue titrating until the blue color disappears. The blank test is to use the above device except that no sample is added, and then titrate after heating for 5 minutes. 4.2.5 Expression of analytical results
The effective chlorine dioxide content (X,) expressed as mass percentage shall be calculated according to formula (1): X, = (Vl Va)c× 0. 013 49
× 100 1. 349(Vi- Vo)c
VThe volume of sodium thiosulfate standard titration solution consumed by the titration test solution, mL. Where:
0. 013 49-
-The volume of sodium thiosulfate standard titration solution consumed by the titration blank solution, ml; The actual concentration of the sodium thiosulfate standard titration solution, mol/1; (1)
The mass of the sample, g;
The mass of chlorine dioxide in grams equivalent to 1.00 ml of sodium thiosulfate standard titration solution [c(Na2S0)=1.000mol/1.1].
4.2.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results is not greater than 0.02%. 4.3 Determination of density
4.3.1 Instruments and equipment
Same as the provisions of 2.3.3.2 in B/T4472--1984. 4.3.2 Analysis steps
Same as the provisions of 2.3.3.3 in (GB/T4472-1984. 4.3.3 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results is not greater than 0.003g/cm. 4.4 Determination of pH value
4.4.1 Instruments and equipment
冏(Chapter 5 of GB/T9724-1988.
4.4.2 Analysis steps
Pour the sample into a beaker and perform the following determination according to Chapter 6 of GB/T9724-1988. 4.4.3 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.2 pH units. 4.5 Determination of arsenic content
Weigh (1.00±0.01)g of sample and add 10mL of (1+3) hydrochloric acid solution as the test solution. Use a pipette to transfer 2.0mL of arsenic standard solution (1mL of solution contains 1μgAs) as the standard and perform the following determination according to the arsenic spot method of GB/T8450.
4.6 Determination of heavy metal content
Weigh (1.00+0.01)g of sample, place in a 100mL beaker, add (1+3) 8ml of hydrochloric acid solution to dissolve, place on an electric stove and boil until nearly 30°C, after cooling, add 1 drop of phenolphthalein indicator solution, neutralize with ammonia solution until the test solution turns pink. Transfer to a 50ml colorimetric tube. 322
HG3669—2000Www.bzxZ.net
Use a pipette to transfer 1mL of lead standard solution (1ml. The solution contains 10μgPb) as the standard, and the following determination is carried out according to Chapter 6 of GB/T84511987.
4.7 Determination of methanol content
4.7.1 Summary of the method
After methanol is oxidized to formaldehyde, it reacts with fuchsin-sulfurous acid to form a blue-purple compound, and the color is compared visually. 4.7.2 Reagents and materials
4.7.2.1 Potassium permanganate-phosphoric acid solution.
Weigh 3g potassium permanganate and add it to a mixture of 15mL phosphoric acid and 70mL water. After dissolving, add water to 100mL. Store in a brown bottle. The storage time should not be too long.
4.7.2.2 Oxalic acid-sulfuric acid solution.
Weigh 5g anhydrous oxalic acid or 7g oxalic acid containing 2 molecules of crystal water, dissolve it in 1+1 sulfuric acid and dilute to 100mlL. 4.7.2.3 Fuchsin-sulfurous acid solution.
Weigh 0.1g of basic fuchsin and grind it into powder. Add 60mL of 80℃ water in batches. Grind it while adding water to dissolve it. Use a dropper to absorb the upper layer of solution and filter it into a 100ml volumetric flask. After cooling, add 10ml of 100g/L sodium sulfite solution and 1ml of hydrochloric acid. Add water to the scale, mix well, and leave it overnight. If the solution has color, add a small amount of activated carbon, stir and filter it. Store it in a brown bottle and store it in a dark place. When the solution turns red, it should be discarded and re-prepared.
4.7.2.4 Methanol standard solution: 1ml is equivalent to 10mg methanol. Weigh 1.000g methanol and place it in a 100mL volumetric flask. Add water to dilute to the scale and shake well. 4.7.2.5 Methanol standard solution: 1ml is equivalent to 1mg methanol. Use a pipette to transfer 10mL of methanol standard solution (4.7.2.4) into a 100mL volumetric flask, add water to dilute to the mark, and shake to mix. This solution is prepared before use.
4.7.3 Analysis steps
Pipette 0.40ml of methanol standard solution (4.7.2.5) into a 25ml stoppered colorimetric tube, transfer 1.0ml of the sample into another colorimetric tube, add water to 5ml, add 2mL of potassium permanganate-phosphoric acid solution respectively, mix, let stand for 10min, add 2ml of oxalic acid-sulfuric acid solution respectively, mix to fade, add 5mL of fuchsin-sulfurous acid solution, mix. Let stand at above 20℃ for 30min, the color of the sample shall not be darker than the standard.
5 Inspection rules
5.1 This standard is divided into type inspection and factory inspection. 5.1.1 All six index items in the requirements are type inspection items. 5.1.2 The effective chlorine dioxide content, density, pH value, content of platinum and heavy metal content are factory inspection items. 5.2 Each batch of food additive stable chlorine dioxide solution shall not exceed 10t. 5.3 Determine the number of sampling units in accordance with the provisions of GB/T6678. When sampling, slowly insert the sampling glass tube to 2/3 of the depth of the container for sampling. Mix the collected samples, the total amount shall not be less than 500mL, and divide them into two clean and dry brown bottles and seal them. Paste labels on the bottles, indicating: manufacturer name, product name, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other bottle is kept for three months for reference.
5.4 The stable chlorine dioxide solution of food additives shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that each batch of products leaving the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the received food additive stable chlorine dioxide solution in accordance with the provisions of this standard. The inspection and acceptance should be carried out within 20 days from the date of arrival of the goods.
5.6 If any index of the inspection result does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-inspection. If even one index of the re-inspection result does not meet the requirements of this standard, the entire batch of products shall be unqualified. 323
6 Marking and labeling
HG 3669 --2000
6.1 The packaging container of food additive stable chlorine dioxide solution shall be firmly and clearly marked, including: manufacturer name, address, product name, trademark, "food additive", net content, batch number or production date, shelf life, production license number, this standard number and the "upward" and "heat-afraid" marks specified in GB191. 6.2 Each batch of food additive stable chlorine dioxide solution shipped out of the factory should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, "food additive", net content, batch number or production date, shelf life, production license number, proof that the product quality complies with this standard and this standard promotion number.
7 Packaging, transportation, storage
7.1 Food additive stable chlorine dioxide solution is packaged in light-proof polyethylene or polypropylene plastic barrels for food. 7.2 Food additive stable chlorine dioxide solution shall not be mixed with acid, reducing substances, organic matter and toxic and harmful substances during transportation.
7.3 Food additive stable fluorine dioxide solution should be stored in a cool and dry place and shall not be mixed with acid, reducing substances, organic matter and toxic and harmful substances.
7.4 The product has a shelf life of one year from the date of production under the conditions of packaging, transportation and storage in accordance with this standard. If it is overdue, it should be re-inspected to see if it complies with the requirements of this standard.
HG3669—2000
Appendix A
(Indicative Appendix)
Determination of fluorine dioxide content
In order to meet the requirements of the relevant units that unconditionally determine the effective chlorine dioxide content, a method for determining the chlorine dioxide content is specially formulated. This method is for reference only. The arbitration method is for the determination of the effective chlorine dioxide content. A1 Method Summary
Use malonic acid to react with the hypochlorite in it to eliminate its influence on the determination of chlorine dioxide content. Stability Chlorine dioxide solution releases oxidizing chlorine dioxide under acidic conditions. Chlorine dioxide oxidizes potassium iodide to release iodine, and then the iodine precipitated by the reaction is titrated with sodium thiosulfate standard titration solution.
A2 Reagents and Materials
A2.1 Potassium iodide.
A2.2 Sulfuric acid solution: 1+1.
A2.3 Malonic acid solution: 100g/L.
A2.4 Sodium thiosulfate standard titration solution, c(NazS2O3) is about 0.1mol/I. A2.5 Starch indicator solution: 5g/L. Useable period is two weeks. A3
Analysis steps
Weigh about 2g of sample (accurate to 0.0002g), place in a 250mL iodine volumetric flask with 50mL water in advance, add 3mL malonic acid solution, mix well, and react for 3min. Add 2g potassium iodide and 3mL sulfuric acid solution, mix well. Place in the dark for 10min. Titrate with sodium thiosulfate standard titration solution, add 1mL starch indicator solution when close to the end point, and continue titrating until the blue color disappears. Perform a blank test at the same time.
A4 Expression of analysis results
The chlorine dioxide (in terms of ClO2) content (X) expressed as a mass percentage is calculated according to formula (A1): X = (V/Vo)c× 0.01349 × 100 = 1.349(V-Vo)em
V, the volume of sodium thiosulfate standard titration solution consumed by the titration test solution, mL; where:
V. ——The volume of sodium thiosulfate standard titration solution consumed by the titration blank solution, mL; the actual concentration of sodium thiosulfate standard titration solution, mol/L; · (A1)
m—-The mass of the sample, g;
0.01349—-The mass of chlorine dioxide expressed in grams equivalent to 1.00mL sodium thiosulfate standard titration solution Lc (NazS2O3) = 1.000mol/LI.
A5 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 0.02%. 3252 Analysis steps
Pour the sample into a beaker and perform the following determination according to Chapter 6 of GB/T9724-1988. 4.4.3 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.2 pH units. 4.5 Determination of arsenic content
Weigh (1.00±0.01)g of sample and add 10mL of (1+3) hydrochloric acid solution as the test solution. Use a pipette to transfer 2.0mL of arsenic standard solution (1mL of solution contains 1μgAs) as the standard and perform the following determination according to the arsenic spot method of GB/T8450.
4.6 Determination of heavy metal content
Weigh (1.00+0.01)g of sample, place in a 100mL beaker, add (1+3) 8ml of hydrochloric acid solution to dissolve, place on an electric stove and boil until nearly 30°C, after cooling, add 1 drop of phenolphthalein indicator solution, neutralize with ammonia solution until the test solution turns pink. Transfer to a 50ml colorimetric tube. 322
HG3669—2000
Use a pipette to transfer 1mL of lead standard solution (1ml. The solution contains 10μgPb) as the standard, and the following determination is carried out according to Chapter 6 of GB/T84511987.
4.7 Determination of methanol content
4.7.1 Summary of the method
After methanol is oxidized to formaldehyde, it reacts with fuchsin-sulfurous acid to form a blue-purple compound, and the color is compared visually. 4.7.2 Reagents and materials
4.7.2.1 Potassium permanganate-phosphoric acid solution.
Weigh 3g potassium permanganate and add it to a mixture of 15mL phosphoric acid and 70mL water. After dissolving, add water to 100mL. Store in a brown bottle. The storage time should not be too long.
4.7.2.2 Oxalic acid-sulfuric acid solution.
Weigh 5g anhydrous oxalic acid or 7g oxalic acid containing 2 molecules of crystal water, dissolve it in 1+1 sulfuric acid and dilute to 100mlL. 4.7.2.3 Fuchsin-sulfurous acid solution.
Weigh 0.1g of basic fuchsin and grind it into powder. Add 60mL of 80℃ water in batches. Grind it while adding water to dissolve it. Use a dropper to absorb the upper layer of solution and filter it into a 100ml volumetric flask. After cooling, add 10ml of 100g/L sodium sulfite solution and 1ml of hydrochloric acid. Add water to the scale, mix well, and leave it overnight. If the solution has color, add a small amount of activated carbon, stir and filter it. Store it in a brown bottle and store it in a dark place. When the solution turns red, it should be discarded and re-prepared.
4.7.2.4 Methanol standard solution: 1ml is equivalent to 10mg methanol. Weigh 1.000g methanol and place it in a 100mL volumetric flask. Add water to dilute to the scale and shake well. 4.7.2.5 Methanol standard solution: 1ml is equivalent to 1mg methanol. Use a pipette to transfer 10mL of methanol standard solution (4.7.2.4) into a 100mL volumetric flask, add water to dilute to the mark, and shake to mix. This solution is prepared before use.
4.7.3 Analysis steps
Pipette 0.40ml of methanol standard solution (4.7.2.5) into a 25ml stoppered colorimetric tube, transfer 1.0ml of the sample into another colorimetric tube, add water to 5ml, add 2mL of potassium permanganate-phosphoric acid solution respectively, mix, let stand for 10min, add 2ml of oxalic acid-sulfuric acid solution respectively, mix to fade, add 5mL of fuchsin-sulfurous acid solution, mix. Let stand at above 20℃ for 30min, the color of the sample shall not be darker than the standard.
5 Inspection rules
5.1 This standard is divided into type inspection and factory inspection. 5.1.1 All six index items in the requirements are type inspection items. 5.1.2 The effective chlorine dioxide content, density, pH value, content of platinum and heavy metal content are factory inspection items. 5.2 Each batch of food additive stable chlorine dioxide solution shall not exceed 10t. 5.3 Determine the number of sampling units in accordance with the provisions of GB/T6678. When sampling, slowly insert the sampling glass tube to 2/3 of the depth of the container for sampling. Mix the collected samples, the total amount shall not be less than 500mL, and divide them into two clean and dry brown bottles and seal them. Paste labels on the bottles, indicating: manufacturer name, product name, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other bottle is kept for three months for reference.
5.4 The stable chlorine dioxide solution of food additives shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that each batch of products leaving the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the received food additive stable chlorine dioxide solution in accordance with the provisions of this standard. The inspection and acceptance should be carried out within 20 days from the date of arrival of the goods.
5.6 If any index of the inspection result does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-inspection. If even one index of the re-inspection result does not meet the requirements of this standard, the entire batch of products shall be unqualified. 323
6 Marking and labeling
HG 3669 --2000
6.1 The packaging container of food additive stable chlorine dioxide solution shall be firmly and clearly marked, including: manufacturer name, address, product name, trademark, "food additive", net content, batch number or production date, shelf life, production license number, this standard number and the "upward" and "heat-afraid" marks specified in GB191. 6.2 Each batch of food additive stable chlorine dioxide solution shipped out of the factory should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, "food additive", net content, batch number or production date, shelf life, production license number, proof that the product quality complies with this standard and this standard promotion number.
7 Packaging, transportation, storage
7.1 Food additive stable chlorine dioxide solution is packaged in light-proof polyethylene or polypropylene plastic barrels for food. 7.2 Food additive stable chlorine dioxide solution shall not be mixed with acid, reducing substances, organic matter and toxic and harmful substances during transportation.
7.3 Food additive stable fluorine dioxide solution should be stored in a cool and dry place and shall not be mixed with acid, reducing substances, organic matter and toxic and harmful substances.
7.4 The product has a shelf life of one year from the date of production under the conditions of packaging, transportation and storage in accordance with this standard. If it is overdue, it should be re-inspected to see if it complies with the requirements of this standard.
HG3669—2000
Appendix A
(Indicative Appendix)
Determination of fluorine dioxide content
In order to meet the requirements of the relevant units that unconditionally determine the effective chlorine dioxide content, a method for determining the chlorine dioxide content is specially formulated. This method is for reference only. The arbitration method is for the determination of the effective chlorine dioxide content. A1 Method Summary
Use malonic acid to react with the hypochlorite in it to eliminate its influence on the determination of chlorine dioxide content. Stability Chlorine dioxide solution releases oxidizing chlorine dioxide under acidic conditions. Chlorine dioxide oxidizes potassium iodide to release iodine, and then the iodine precipitated by the reaction is titrated with sodium thiosulfate standard titration solution.
A2 Reagents and Materials
A2.1 Potassium iodide.
A2.2 Sulfuric acid solution: 1+1.
A2.3 Malonic acid solution: 100g/L.
A2.4 Sodium thiosulfate standard titration solution, c(NazS2O3) is about 0.1mol/I. A2.5 Starch indicator solution: 5g/L. Useable period is two weeks. A3
Analysis steps
Weigh about 2g of sample (accurate to 0.0002g), place in a 250mL iodine volumetric flask with 50mL water in advance, add 3mL malonic acid solution, mix well, and react for 3min. Add 2g potassium iodide and 3mL sulfuric acid solution, mix well. Place in the dark for 10min. Titrate with sodium thiosulfate standard titration solution, add 1mL starch indicator solution when close to the end point, and continue titrating until the blue color disappears. Perform a blank test at the same time.
A4 Expression of analysis results
The chlorine dioxide (in terms of ClO2) content (X) expressed as a mass percentage is calculated according to formula (A1): X = (V/Vo)c× 0.01349 × 100 = 1.349(V-Vo)em
V, the volume of sodium thiosulfate standard titration solution consumed by the titration test solution, mL; where:
V. ——The volume of sodium thiosulfate standard titration solution consumed by the titration blank solution, mL; the actual concentration of sodium thiosulfate standard titration solution, mol/L; · (A1)
m—-The mass of the sample, g;
0.01349—-The mass of chlorine dioxide expressed in grams equivalent to 1.00mL sodium thiosulfate standard titration solution Lc (NazS2O3) = 1.000mol/LI.
A5 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 0.02%. 3252 Analysis steps
Pour the sample into a beaker and perform the following determination according to Chapter 6 of GB/T9724-1988. 4.4.3 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.2 pH units. 4.5 Determination of arsenic content
Weigh (1.00±0.01)g of sample and add 10mL of (1+3) hydrochloric acid solution as the test solution. Use a pipette to transfer 2.0mL of arsenic standard solution (1mL of solution contains 1μgAs) as the standard and perform the following determination according to the arsenic spot method of GB/T8450.
4.6 Determination of heavy metal content
Weigh (1.00+0.01)g of sample, place in a 100mL beaker, add (1+3) 8ml of hydrochloric acid solution to dissolve, place on an electric stove and boil until nearly 30°C, after cooling, add 1 drop of phenolphthalein indicator solution, neutralize with ammonia solution until the test solution turns pink. Transfer to a 50ml colorimetric tube. 322
HG3669—2000
Use a pipette to transfer 1mL of lead standard solution (1ml. The solution contains 10μgPb) as the standard, and the following determination is carried out according to Chapter 6 of GB/T84511987.
4.7 Determination of methanol content
4.7.1 Summary of the method
After methanol is oxidized to formaldehyde, it reacts with fuchsin-sulfurous acid to form a blue-purple compound, and the color is compared visually. 4.7.2 Reagents and materials
4.7.2.1 Potassium permanganate-phosphoric acid solution.
Weigh 3g potassium permanganate and add it to a mixture of 15mL phosphoric acid and 70mL water. After dissolving, add water to 100mL. Store in a brown bottle. The storage time should not be too long.
4.7.2.2 Oxalic acid-sulfuric acid solution.
Weigh 5g anhydrous oxalic acid or 7g oxalic acid containing 2 molecules of crystal water, dissolve it in 1+1 sulfuric acid and dilute to 100mlL. 4.7.2.3 Fuchsin-sulfurous acid solution.
Weigh 0.1g of basic fuchsin and grind it into powder. Add 60mL of 80℃ water in batches. Grind it while adding water to dissolve it. Use a dropper to absorb the upper layer of solution and filter it into a 100ml volumetric flask. After cooling, add 10ml of 100g/L sodium sulfite solution and 1ml of hydrochloric acid. Add water to the scale, mix well, and leave it overnight. If the solution has color, add a small amount of activated carbon, stir and filter it. Store it in a brown bottle and store it in a dark place. When the solution turns red, it should be discarded and re-prepared.
4.7.2.4 Methanol standard solution: 1ml is equivalent to 10mg methanol. Weigh 1.000g methanol and place it in a 100mL volumetric flask. Add water to dilute to the scale and shake well. 4.7.2.5 Methanol standard solution: 1ml is equivalent to 1mg methanol. Use a pipette to transfer 10mL of methanol standard solution (4.7.2.4) into a 100mL volumetric flask, add water to dilute to the mark, and shake to mix. This solution is prepared before use.
4.7.3 Analysis steps
Pipette 0.40ml of methanol standard solution (4.7.2.5) into a 25ml stoppered colorimetric tube, transfer 1.0ml of the sample into another colorimetric tube, add water to 5ml, add 2mL of potassium permanganate-phosphoric acid solution respectively, mix, let stand for 10min, add 2ml of oxalic acid-sulfuric acid solution respectively, mix to fade, add 5mL of fuchsin-sulfurous acid solution, mix. Let stand at above 20℃ for 30min, the color of the sample shall not be darker than the standard.
5 Inspection rules
5.1 This standard is divided into type inspection and factory inspection. 5.1.1 All six index items in the requirements are type inspection items. 5.1.2 The effective chlorine dioxide content, density, pH value, content of platinum and heavy metal content are factory inspection items. 5.2 Each batch of food additive stable chlorine dioxide solution shall not exceed 10t. 5.3 Determine the number of sampling units in accordance with the provisions of GB/T6678. When sampling, slowly insert the sampling glass tube to 2/3 of the depth of the container for sampling. Mix the collected samples, the total amount shall not be less than 500mL, and divide them into two clean and dry brown bottles and seal them. Paste labels on the bottles, indicating: manufacturer name, product name, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other bottle is kept for three months for reference.
5.4 The stable chlorine dioxide solution of food additives shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that each batch of products leaving the factory meets the requirements of this standard. 5.5 The user has the right to inspect and accept the received food additive stable chlorine dioxide solution in accordance with the provisions of this standard. The inspection and acceptance should be carried out within 20 days from the date of arrival of the goods.
5.6 If any index of the inspection result does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-inspection. If even one index of the re-inspection result does not meet the requirements of this standard, the entire batch of products shall be unqualified. 323
6 Marking and labeling
HG 3669 --2000
6.1 The packaging container of food additive stable chlorine dioxide solution shall be firmly and clearly marked, including: manufacturer name, address, product name, trademark, "food additive", net content, batch number or production date, shelf life, production license number, this standard number and the "upward" and "heat-afraid" marks specified in GB191. 6.2 Each batch of food additive stable chlorine dioxide solution shipped out of the factory should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, "food additive", net content, batch number or production date, shelf life, production license number, proof that the product quality complies with this standard and this standard promotion number.
7 Packaging, transportation, storage
7.1 Food additive stable chlorine dioxide solution is packaged in light-proof polyethylene or polypropylene plastic barrels for food. 7.2 Food additive stable chlorine dioxide solution shall not be mixed with acid, reducing substances, organic matter and toxic and harmful substances during transportation.
7.3 Food additive stable fluorine dioxide solution should be stored in a cool and dry place and shall not be mixed with acid, reducing substances, organic matter and toxic and harmful substances.
7.4 The product has a shelf life of one year from the date of production under the conditions of packaging, transportation and storage in accordance with this standard. If it is overdue, it should be re-inspected to see if it complies with the requirements of this standard.
HG3669—2000
Appendix A
(Indicative Appendix)
Determination of fluorine dioxide content
In order to meet the requirements of the relevant units that unconditionally determine the effective chlorine dioxide content, a method for determining the chlorine dioxide content is specially formulated. This method is for reference only. The arbitration method is for the determination of the effective chlorine dioxide content. A1 Method Summary
Use malonic acid to react with the hypochlorite in it to eliminate its influence on the determination of chlorine dioxide content. Stability Chlorine dioxide solution releases oxidizing chlorine dioxide under acidic conditions. Chlorine dioxide oxidizes potassium iodide to release iodine, and then the iodine precipitated by the reaction is titrated with sodium thiosulfate standard titration solution.
A2 Reagents and Materials
A2.1 Potassium iodide.
A2.2 Sulfuric acid solution: 1+1.
A2.3 Malonic acid solution: 100g/L.
A2.4 Sodium thiosulfate standard titration solution, c(NazS2O3) is about 0.1mol/I. A2.5 Starch indicator solution: 5g/L. Useable period is two weeks. A3
Analysis steps
Weigh about 2g of sample (accurate to 0.0002g), place in a 250mL iodine volumetric flask with 50mL water in advance, add 3mL malonic acid solution, mix well, and react for 3min. Add 2g potassium iodide and 3mL sulfuric acid solution, mix well. Place in the dark for 10min. Titrate with sodium thiosulfate standard titration solution, add 1mL starch indicator solution when close to the end point, and continue titrating until the blue color disappears. Perform a blank test at the same time.
A4 Expression of analysis results
The chlorine dioxide (in terms of ClO2) content (X) expressed as a mass percentage is calculated according to formula (A1): X = (V/Vo)c× 0.01349 × 100 = 1.349(V-Vo)em
V, the volume of sodium thiosulfate standard titration solution consumed by the titration test solution, mL; where:
V. ——The volume of sodium thiosulfate standard titration solution consumed by the titration blank solution, mL; the actual concentration of sodium thiosulfate standard titration solution, mol/L; · (A1)
m—-The mass of the sample, g;
0.01349—-The mass of chlorine dioxide expressed in grams equivalent to 1.00mL sodium thiosulfate standard titration solution Lc (NazS2O3) = 1.000mol/LI.
A5 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 0.02%. 32502%. 325
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