Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T2766—1996
Industrial Sodium Bromate
Published on 1996-01-24
Ministry of Chemical Industry of the People's Republic of China
Implemented on 1997-01-01
WHG/T2766—1996
This standard is formulated based on the standards of well-known foreign companies. The main technical differences from this standard are as follows: 1 The technical indicators of this standard only have one level. This standard has two levels of superior products and first-class products according to my country's national conditions. 2 The standard has eight indicators, namely sodium bromate, bromide, moisture, sulfate, heavy metals, pH value, arsenic, and absorbance. On this basis, this standard has added two indicators, namely chloride and chlorate, and iron, according to the standards of other foreign companies and the actual situation of domestic products. 3 The indicator parameters of superior products in this standard are consistent with the standards of well-known foreign companies, except for pH value, iron, chloride and chlorate. The pH value of the standard of a famous foreign company is 6.5±1, and this standard is 6.5±0.5.4 The standard of a famous foreign company has no test method. The test method of this standard refers to the test methods of standards such as HG2681-95 "Food Additive Potassium Bromate" and GB/T650-77 "Chemical Reagent Potassium Bromate" and GB/T3049-86 "General Method for Determination of Iron Content in Chemical Products - O-Phenanthroline Spectrophotometry" (neqISO6685:1982). This standard was 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 the Tianjin Chemical Research Institute of the Ministry of Chemical Industry. The drafting units of this standard are: Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Beijing Chemical Plant No. 4, and Changshu Organic Chemical Research Institute. The main drafters of this standard are: Wang Shumin, Xu Shanquan, Zhao Mingshan, and Shi Jie. I
W.1 Scope
Chemical Industry Standard of the People's Republic of China
Industrial Sodium Bromate
HG/T2766—1996
This standard specifies the requirements, sampling, test methods, marking, packaging, transportation, storage and safety of industrial sodium bromate. This standard applies to sodium bromate produced by electrolysis and chemical methods. This product is mainly used to prepare inorganic chemical products and chemical reagents for the determination of phenols; it is also commonly used as an oxidant, cosmetic cold perm agent, printing and dyeing auxiliary, and also used for the extraction and purification of precious metals. Molecular formula: 2NaBrOs
Relative molecular mass: 150.90 (according to the 1991 international relative atomic mass) 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. GB19090 Dangerous Goods Packaging Marking
GB191-90 Pictorial Marking for Packaging Storage and Transportation
GB/T601-88 Preparation of Standard Solutions for Titration Analysis (Volumetric Analysis) of Chemical Reagents Preparation of Standard Solutions for Determination of Impurities of Chemical Reagents (negISO6353/1:1982)GB/T602-88
GB/T603-88
Preparation of Preparations and Products Used in Chemical Reagent Test Methods (neqISO6353/1:1982)GB/T1250-89||t t||Expression method and determination method of limit value GB/T3049-86
General method for determination of iron content in chemical products O-phenanthroline spectrophotometry (neqISO6685:1982)
GB/T6678-86 General rules for sampling of chemical products GB/T6682-92 Specification and test method for water used in analytical laboratories (eqvISO3696:1987) GB/T8450-87 Determination method in food additives 3 Requirements
3.1 Appearance, this product is white crystalline particles or crystalline powder. 3.2 Industrial sodium bromate should meet the requirements of Table 1. Table 1 Requirements
Sodium bromate (NaBrOs) content, %
Bromide (as Br) content, %
Sulfate (as SO,) content, %
Approved by the Ministry of Chemical Industry of the People's Republic of China on January 24, 1996
Superior product
First-class product
Implemented on January 1, 1997
W.bzs oso.coD Moisture, %
Absorbance (200g/L solution)
Nitride and chlorate (as C1) content, %Iron (Fe) content, %
Heavy metal (as Pb) content, %
Arsenic (As) content, %
pH value (100g/L solution)
4 Sampling
4.1 Each batch of products shall not exceed 5t.
HG/T2766—1996
Table 1 (end)
Superior products
4.2 Determine the number of sampling units in accordance with the provisions of 6.6 of GB/T6678. Each barrel is a packaging unit. Standard
First-class products
When sampling, insert the sampler obliquely from the center of the packaging container to 3/4 of the material layer for sampling. After mixing the collected samples, divide them into quarters to about 500g, and immediately put them into two clean and dry wide-mouth bottles with ground stoppers and seal them. Paste labels on the bottles, indicating the manufacturer name, product name, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample and the other is kept for three months for reference. 4.3 If one of the test results does not meet the requirements of this standard, re-sample from twice the amount of packaging should be verified. If only one of the test results does not meet the requirements of this standard, the entire batch of products will be unqualified. 5 Test methods
5.1 All ten index items specified in this standard are type test items, among which the electrolytic process uses sodium bromate, bromide, moisture, sulfate, and absorbance as routine test items, and the chemical process uses sodium bromate, bromide, moisture, sulfate, absorbance, chloride and chlorate as routine test items. The test should be conducted batch by batch. Under normal production conditions, type tests should be conducted at least once every three months.
5.2 The rounded value comparison method specified in 5.2 of GB/T1250 is used to determine whether the test results meet the standard. 5.3 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, preparations and products used in the test are prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603 unless otherwise specified.
5.4 Determination of sodium bromate content
5.4.1 Summary of the method
Sodium bromate reacts with potassium iodide in an acidic solution to precipitate iodine, and then is titrated with a sodium thiosulfate standard titration solution. The sodium bromate content is determined based on the consumption of the sodium thiosulfate standard titration solution. 5.4.2 Reagents and materials
5.4.2.1 Potassium iodide;
W.bzsoso.coD5.4.2.2 Hydrochloric acid solution: 1+1;
5.4.2.3 Starch indicator solution: 10g/L; HG/T2766-1996
5.4.2.4 Standard titration solution of sodium thiosulfate: c (Na2S20s) is about 0.1mol/L; 5.4.3 Analysis steps
Weigh about 0.8g of sample (accurate to 0.0002g), put it in a 250mL beaker, dissolve it with water, transfer it to a 250mL volumetric flask, dilute it to the mark with water, and shake it well. Transfer 25.0mL of the solution into a 500mL iodine volumetric flask, add 2g potassium iodide and 5mL hydrochloric acid solution, and shake it well. Add water to seal the mouth, place in the dark for 5 minutes, then add 150 mL of water below 10°C and titrate with sodium thiosulfate standard titration solution. Add 3 mL of starch solution near the end point and continue to titrate the solution until the blue color disappears. Perform a blank test at the same time. 5.4.4 Expression of analysis results
The sodium bromate (NaBrOs) content (X1) expressed as mass percentage is calculated according to formula (1): X; =V) 0 025 15x100
m×250
_25.15(V-Vo)c
Where: V is the volume of sodium thiosulfate standard titration solution consumed by the titration test solution, mL; V. The volume of sodium thiosulfate standard titration solution consumed by titrating the blank solution, mL; c——the actual concentration of sodium thiosulfate standard titration solution, mol/L; m—the mass of the sample, g
(1)
5——the mass of 0.02515
sodium bromate expressed in grams equivalent to 1.00mL sodium thiosulfate standard titration solution [c(NaS20s)=1.000mol/L).
5.4.5 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%5.5 Determination of bromide content
5.5.1 Method summary
Add sulfuric acid solution to excess bromate and bromide solution. After the two react, free bromine will be released. Determine the bromide content in the test solution based on the color of bromine.
5.5.2 Reagents and materials
5.5.2.1 Sulfuric acid solution: 1+8;
5.5.2.2 Bromine standard solution: 1mL solution contains 1mgBr. Preparation: Weigh 1.490g potassium bromide and dissolve it in water, transfer it into a 1000mL volumetric flask, dilute to the scale, and store it in a brown bottle. 5.5.3 Analysis steps
Weigh about 3g of sample (accurate to 0.01g), place it in a 100mL colorimetric tube, add 85mL hot water, cool it, add 0.5mL sulfuric acid solution, shake it well, and let it stand for 30min. The yellow color should not be darker than the standard colorimetric solution. The standard colorimetric solution is to take 1g of the sample (accurate to 0.01g), place it in a 100mL colorimetric tube, take 0.8mL (superior product) and 1.2mL (first-class product) of bromine standard solution, and start the same treatment as the sample from "add 85mL hot water". 5.6 Determination of sulfate content
5.6.1 Method summary
In an acidic medium, sulfate ions and barium ions form a precipitate to make the solution turbid. The sulfate content in the solution is determined based on the turbidity of the solution.
5.6.2 Reagents and materials
W5.6.2.195% ethanol,
5.6.2.2 Hydrochloric acid solution: 1+1;
5.6.2.3 Hydrochloric acid solution: 1+3;
5.6.2.4 Chlorinated iodine solution: 250g/L;
HG/T2766—1996
5.6.2.5 Sulfate standard solution: 1mL solution contains 0.04mgS04. Preparation: Take 20.0mL of sulfate standard solution prepared according to GB/T602 and place it in a 50mL volumetric flask, dilute to the mark, and shake well; this solution is prepared before use.
5.6.3 Analysis steps
Weigh about 1g of sample (accurate to 0.001g), place in a 100mL beaker, slowly add 20mL of hydrochloric acid solution (5.6.2.2), evaporate to dryness on a water bath. Add another 10mL of hydrochloric acid solution (5.6.2.2), evaporate to dryness, dissolve the residue in water, transfer to a 25mL volumetric flask, dilute to scale, and shake well. Dry filter, take 10.0mL of filtrate, place in a 25mL colorimetric tube, add 5mL of 95% ethanol and 1mL of hydrochloric acid solution (5.6.2.3), add 3mL of barium chloride solution while shaking continuously, dilute to scale, shake well, and let stand for 10 minutes. The turbidity presented shall not be greater than that of the standard turbidimetric solution.
The standard turbidity solution is 1.0mL (superior product) and 3.0mL (first-class product) of sulfate standard solution, placed in a 25mL colorimetric tube, diluted to 10mL, starting from "add 5mL of 95% ethanol", and treated in the same way as the test solution. 5.7 Determination of moisture
5.7.1 Summary of method
Bake the sample at 105±2℃ to constant weight, and determine the moisture content based on the weight loss before and after heating. 5.7.2 Instruments and equipment
Weighing bottle: α50mm×30mm.
5.7.3 Analysis steps
Weigh about 2g of sample (accurate to 0.0002g), place it in a weighing bottle that has been weighed to a constant weight, move it into an electric constant temperature drying oven, and heat it at 105±2℃. Take it out and put it in a desiccator, cool it to room temperature, and weigh it. Do this until constant weight. 5.7.4 Expression of analysis results
The water content (X2) expressed as mass percentage is calculated according to formula (2): X2-mlm2×100
Wherein: m1—mass of weighing bottle and sample before heating, g; m2—mass of weighing bottle and sample after heating, g; m——mass of sample, g.
5.7.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.02%. 5.8 Determination of absorbance
5.8.1 Summary of method
The fine suspended matter in the test solution follows the Lambert-Beer law at 380nm, and its absorbance can be measured accordingly. 5.8.2 Instruments and equipment
Spectrophotometer: with an absorption cell with a thickness of 4cm, and the wavelength can be adjusted to 380nm. 5.8.3 Analysis steps
Weigh about 20g of sample (accurate to 0.01g), place in a 100mL beaker, add water to dissolve, transfer to a 100mL volumetric flask, dilute to scale, and shake well. Use a spectrophotometer to measure its absorbance at 380nm, using a 4cm absorption cell and water as a reference.
5.8.4 Allowable difference
HG/T2766—1996
Take the arithmetic mean of the parallel determination results as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.003. 5.9 Determination of chloride and chlorate content
5.9.1 Summary of method
In an acidic solution, chlorate is reduced to chloride with sulfurous acid, and chloride is precipitated with silver nitrate. The chloride and chlorate content in the sample is determined based on the turbidity of the solution.
5.9.2 Reagents and materials
5.9.2.1 Sulfurous acid;
5.9.2.2 Nitric acid solution: 1+2;
5.9.2.3 Silver nitrate solution: 17g/L;
5.9.2.4 Chlorine standard solution: 1mL solution contains 0.01mgCl. Preparation: Take 10.0mL of chlorine standard solution prepared according to GB/T602, dilute to 100mL with water, and shake well. The solution is prepared before use.
5.9.3 Analysis steps
Weigh about 1g of sample (accurate to 0.001g), place in a 200mL beaker, add 15mL of water to dissolve, and add sulfurous acid (about 20mL) dropwise until the solution is colorless. Boil slowly for 2min to allow excess sulfur dioxide to escape. Cool, add 50mL nitric acid solution, heat until the solution is colorless, wash the bottle wall with a small amount of water, and continue heating for 15 minutes. Cool, transfer to a 250mL volumetric flask, dilute to the scale, and shake. Take 5.0mL and place it in a 25mL colorimetric tube, dilute to 20mL, add 2mL nitric acid solution and 1mL silver nitrate solution, dilute to the scale, shake well, and place for 10 minutes. The turbidity presented shall not be greater than that of the standard turbidity solution. The standard turbidity solution is to take 1.0mL (superior product) and 4.0mL (first-class product) of chlorine standard solution, place it in a 25mL colorimetric tube, start from "dilute to 20mL, add 2mL nitric acid solution...", and treat it in the same way as the sample. 5.10 Determination of iron content
5.10.1 Summary of method
According to Chapter 2 of GB/T3049.
5.10.2 Reagents and materials
Hydrochloric acid solution: 1+1;Www.bzxZ.net
Others shall be in accordance with Chapter 3 of GB/T3049.
5.10.3 Instruments and equipment
Spectrophotometer: with an absorption cell of 3 cm thickness. 5.10.4 Analysis steps
5.10.4.1 Drawing of working curve
Draw the working curve using a 3 cm absorption cell and the corresponding amount of iron standard solution as specified in 5.3 of GB/T3049. 5.10.4.2 Preparation of test solution
Weigh about 10g of sample (accurate to 0.01g), place in evaporating dish III, add 70mL hydrochloric acid solution (1+1), 2 drops of sulfuric acid, evaporate to dryness on a water bath, add 20mL hydrochloric acid solution (1+1), evaporate to dryness again, dissolve the residue in water, transfer to a 100mL volumetric flask, dilute to scale, and shake well. This is solution A. Solution A is used to determine the content of iron and heavy metals. 5.10.4.3 Preparation of blank test solution
Prepare blank test solution according to the preparation method of test solution except that no sample is added. 5.10.4.4 Determination
Take 40.0mL of solution A and blank test solution, place them in 100mL volumetric flasks respectively, and follow 5.3.2 of GB/T3049, starting from "add water to about 60mL". 5.10.5 Expression of analysis results
The iron (Fe) content (X:) expressed as a mass percentage is calculated according to formula (3): 5
W.bzsoso.coIHG/T2766-1996
(m,-m.)X10-8
m×100
Wherein: m1——the mass of iron in the test solution found from the working curve, mg; mo—the mass of iron in the blank test solution found from the working curve, mg; m——the mass of the sample, g.
5.10.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.0002%. 5.11 Determination of heavy metal content
5.11.1 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. 5.11.2 Reagents and Materials
5.11.2.1 Acetic acid solution: 1+17
5.11.2.2 Ammonia solution: 2+3;
5.11.2.3 Saturated hydrogen sulfide water: This solution is prepared before use; 5.11.2.4 Lead standard solution: 1mL solution contains 0.005mgPb. Prepare before use. Preparation: Take 5.0mL of the lead standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute to the scale with water, and shake well.
5.11.3 Analysis steps
Take 20.0mL solution A (5.10.4.2), place it in a 50mL colorimetric tube, neutralize it with ammonia solution, add 1mL acetic acid solution and 10mL freshly prepared saturated hydrogen sulfide water, dilute it with water to the scale, shake it well, and let it stand for 10 minutes. The dark color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 10.0mL solution A (5.10.4.2) and 1.0mL (superior product) and 2.0mL (first-class product) lead standard solution, respectively, placed in 50mL colorimetric tubes, starting from "neutralization with ammonia solution", and treated in the same way as the test solution. 5.12 Determination of arsenic content
5.12.1 Method summary
According to 2.1 of GB/T8450.
5.12.2 Reagents and materials
Hydrochloric acid solution: 1+1;
Others are in accordance with 2.2 of GB/T8450.
5.12.3 Instruments and equipment
Same as 2.3 of GB/T8450.
5.12.4 Analysis steps
Weigh about 0.50g of sample (accurate to 0.001g), place it in a 50mL beaker, add 5mL of hot water to dissolve, add 5mL of hydrochloric acid, evaporate to dryness on a water bath, dissolve the residue with 5mL of water, transfer all to the arsenic test bottle, and operate according to 2.4 of GB/T8450. The standard colorimetric solution is 1.0mL (superior product) and 2.5mL (first-class product) of arsenic standard solution, placed in the arsenic test bottle, and then treated in the same way as the test solution according to 2.4 of GB/T8450. 6
5.13 Determination of pH value
5.13.1 Summary of method
HG/T2766—1996
Use glass electrode as measuring electrode and calomel electrode as reference electrode to determine pH value of test solution. 5.13.2 Reagents and materials
Water without carbon dioxide.
5.13.3 Instruments and equipment
pH meter: the graduation value is 0.1pH unit. Equipped with saturated calomel electrode and glass electrode. 5.13.4 Analysis steps
Weigh about 10g sample (accurate to 0.01g), place it in a 100mL beaker, dissolve it in water without carbon dioxide, transfer it to a 100mL volumetric flask, dilute to the scale, and shake well. Use an acidometer to determine pH value of test solution. 5.13.5 Allowable difference
The arithmetic mean of the parallel determination results shall be taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.1 pH unit. 6 Marking, packaging, transportation, storage
6.1 The packaging barrels of industrial sodium bromate shall be firmly and clearly marked, including the manufacturer's name, address, product name, trademark, grade, net weight, batch number or production date, and the number of this standard, as well as the "oxidant" specified in GB190 and the "heat-afraid" and "moisture-afraid" marks specified in GB191.
6.2 Each batch of industrial sodium bromate leaving the factory shall be accompanied by a quality certificate. The content includes the manufacturer's name, address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 6.3 Industrial sodium bromate is packaged in cardboard barrels. The inner packaging adopts double-layer polyethylene plastic film bags with a thickness of not less than 0.08mm; the outer packaging adopts cardboard barrels with a thickness of not less than 4mm. Its performance and inspection methods shall comply with relevant regulations. The net weight of each barrel is 50kg or 25kg. If the user has other requirements for packaging, it shall be negotiated. 6.4 When packing industrial sodium bromate, the inner double-layer plastic bag shall be folded in half with polypropylene strapping rope or rope of equivalent quality, and the mouth shall be tied separately, or sealed with other equivalent methods. The outer packaging barrel shall be clamped with a clamping ring and the latch shall be inserted. 6.5 Industrial sodium bromate should be covered during transportation to prevent sun exposure, rain, and moisture. Open flames are strictly prohibited to prevent impact, damage and friction. Transportation requirements shall be implemented in accordance with Class 5.1 oxidants and dangerous goods regulations UN1494. 6.6 Industrial sodium bromate should be stored in a cool and dry place to prevent rain and moisture. Prevent sun exposure and heat. 7 Safety
Industrial sodium bromate is a strong oxidant. Solid sodium bromate reacts violently with cyanide when heated or rubbed. This product can form explosive mixtures with combustibles, powdered metals or ammonium compounds. These mixtures are sensitive to friction and easily ignite. This product can cause an explosion when exposed to fire. 7
W.bzsosO.coI2 Each batch of industrial sodium bromate shipped out of the factory should be accompanied by a quality certificate. The content includes the manufacturer's name, address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 6.3 Industrial sodium bromate is packaged in cardboard barrels. The inner packaging is a double-layer polyethylene plastic film bag with a thickness of not less than 0.08mm; the outer packaging is a cardboard barrel with a thickness of not less than 4mm, and its performance and inspection methods should comply with relevant regulations. The net weight of each barrel is 50kg or 25kg. If the user has other requirements for packaging, negotiate to resolve. 6.4 When packaging industrial sodium bromate, the inner double-layer plastic bag is folded in half with polypropylene strapping rope or rope of equivalent quality, and the mouth is tied separately, or sealed with other equivalent methods. The outer packaging barrel is clamped with a clamping ring and the latch is inserted. 6.5 Industrial sodium bromate should be covered during transportation to prevent sun exposure, rain, moisture, and open flames are strictly prohibited to prevent impact, damage and friction. Transportation requirements are in accordance with Class 5.1 Oxidants, Dangerous Goods Regulations UN1494. 6.6 Industrial sodium bromate should be stored in a cool, dry place, protected from rain and moisture. Protect from sunlight and heat. 7 Safety
Industrial sodium bromate is a strong oxidant. Solid sodium bromate reacts violently with cyanide when heated or rubbed. This product can form explosive mixtures with combustibles, powdered metals or ammonium compounds. These mixtures are sensitive to friction and are easy to ignite. This product can cause explosions when exposed to fire. 7
W.bzsosO.coI2 Each batch of industrial sodium bromate shipped out of the factory should be accompanied by a quality certificate. The content includes the manufacturer's name, address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 6.3 Industrial sodium bromate is packaged in cardboard barrels. The inner packaging is a double-layer polyethylene plastic film bag with a thickness of not less than 0.08mm; the outer packaging is a cardboard barrel with a thickness of not less than 4mm, and its performance and inspection methods should comply with relevant regulations. The net weight of each barrel is 50kg or 25kg. If the user has other requirements for packaging, negotiate to resolve. 6.4 When packaging industrial sodium bromate, the inner double-layer plastic bag is folded in half with polypropylene strapping rope or rope of equivalent quality, and the mouth is tied separately, or sealed with other equivalent methods. The outer packaging barrel is clamped with a clamping ring and the latch is inserted. 6.5 Industrial sodium bromate should be covered during transportation to prevent sun exposure, rain, moisture, and open flames are strictly prohibited to prevent impact, damage and friction. Transportation requirements are in accordance with Class 5.1 Oxidants, Dangerous Goods Regulations UN1494. 6.6 Industrial sodium bromate should be stored in a cool, dry place, protected from rain and moisture. Protect from sunlight and heat. 7 Safety
Industrial sodium bromate is a strong oxidant. Solid sodium bromate reacts violently with cyanide when heated or rubbed. This product can form explosive mixtures with combustibles, powdered metals or ammonium compounds. These mixtures are sensitive to friction and are easy to ignite. This product can cause explosions when exposed to fire. 7
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