Some standard content:
HG2937—1999
This standard is a non-equivalent revision of the chemical industry standard HG2937—1987 (1997) "Feed Grade Sodium Selenite" by the United States Pharmacopoeia (USPXXII). The main technical differences between this standard and the United States Pharmacopoeia are as follows: The United States Pharmacopoeia stipulates six indicators of sodium selenite content, solubility, carbonate, chloride, nitrate, selenate and sulfate content; considering that this standard is feed grade, only three indicators are set, namely sodium selenite content, dissolution test, selenate and sulfate content, and an additional drying loss indicator is set. The determination method of sodium selenite content in the United States Pharmacopoeia is relatively complicated, and this revision adopts the indirect iodine method for determination. The main technical differences between this standard and HG2937--1987 (1997) are as follows: The original standard stipulates that the indicators of selenate and sulfate are qualified; this standard stipulates that their indicators are not more than 0.03% according to the provisions of the United States Pharmacopoeia.
-Determination of sodium selenite content According to the provisions of the Chinese Veterinary Pharmacopoeia (1990 edition), carbon disulfide was replaced by chloroform. The determination of mono-selenate and sulfate content adopts the method specified in the United States Pharmacopoeia. This standard will replace HG2937~1987 (1997) from the date of implementation. This standard was proposed by the former Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the jurisdiction of the Inorganic Chemical Branch of the National Technical Committee for Chemical Standardization. The drafting units of this standard are: Tianjin Chemical Research Institute of the Ministry of Chemical Industry and Tianjin Veterinary Drug Factory No. 2. The main drafters of this standard are: Guo Fengxin, Gao Zhanyou, Ma Ling, and Yao Jinjuan. This standard was first issued in 1987, adjusted to a mandatory chemical industry standard in 1992, and numbered HG2937--1987 (1997) in 1997.
This standard is entrusted to the Inorganic Chemical Branch of the National Technical Committee for Chemical Standardization for interpretation. 173
Chemical Industry Standard of the People's Republic of China
Feed Grade
Sodium Selenite
Feed Grade Sodium Selenite
HG2937..1999
Replaces HG29371987(1997)
This standard specifies the requirements, test methods, inspection rules, marking, labeling, packaging, transportation, storage and safety of feed grade sodium selenite. This standard applies to feed grade sodium selenite produced by the reaction of sodium hydroxide and selenious acid. This product is mainly used as the raw material of selenium premix in feed processing
Molecular weight: Na, SeO
Relative molecular weight: 172.94 (according to the 1995 international relative atomic mass) 2
Cited Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were all valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest version of the following standards. GB190-1990 Dangerous Goods Packaging Marking
GB/r 601---1988
Chemical Reagents Preparation of Standard Solutions for Titration Analysis (Volumetric Analysis) GB/T 602---1988
Chemical Reagents
Preparation of Standard Solutions for Impurity Determination
GB/T 603-- 1988
GB/T 6678--- 1986
Chemical Reagents Preparation of Preparations and Products Used in Test Methods General Rules for Sampling of Chemical Products
GB/T 6682-- 1992
GR 10648---1993
Specifications and test methods for water used in analytical laboratories (neqIS0) 3696:1987)Feed label
GB/T15346--1994Chemical reagents
3 Requirements
3.1 Appearance: colorless granular powder.
Packaging and marking
3.2Feed grade sodium selenite shall meet the requirements of Table 1. Item
Content of sodium selenite (NazSr(),) (based on basis), %Content of sodium selenite (based on Se) (based on basis).%Loss on drying.%
Dissolution test
Content of selenate and sulfate.%
Test method
Qiu 1 Requirements
Completely soluble, clear and transparent
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 1 water specified in GB/T6682, approved by the State Administration of Petroleum and Chemical Industry on June 16, 1999, 174
Implementation on June 1, 2000
HG 2937-1999
The standard titration solutions, impurity standard solutions, preparations and products used in the test shall be prepared in accordance with the provisions of G3/T601, GB/T602 and GB/T603 unless otherwise specified.
Safety Tips: The strong acids and alkalis used in this standard are corrosive. Users should be careful when handling them to avoid splashing on the skin. 4.1 Identification Test
4.1.1 Reagents and Materials
4.1.1.1 Sodium ethylenediaminetetraacetic acid solution: 150g/L. 4.1.1.2 Formic acid solution: 1+9.
4.1.1.3 Hydrochloric acid solution: 1+1.
4.1.1.4 Selenium reagent (hydrochloric acid-3,3-diaminobenzidine) solution: 5g/1. 4.1.2 Instruments and equipment
4.1.3 Identification method
4.1.3.1 Identification of selenite ions
Take a small amount of sample, add 5mL of water to dissolve, add 5 drops of disodium ethylenediaminetetraacetic acid solution and 5 drops of formic acid solution. Use hydrochloric acid solution to adjust the pH value of the solution to 2~~3 (check with pH test paper), add 5 drops of selenium reagent solution, shake, and leave for 10 minutes, and a yellow precipitate will be produced. 4.1.3.2 Identification of sodium ions
Dip the hydrochloric acid solution with a platinum wire and burn it in a colorless flame until it is colorless. Dip the sample and burn it on the flame, and the flame is yellow. 4.2 Determination of sodium selenite content
4.2.1 Method summary
In a strong acidic medium, sodium selenite and potassium iodide undergo an oxidation-reduction reaction to produce free iodine. The free iodine produced is titrated with sodium thiosulfate standard titration solution. Starch is used as an indicator to determine the reaction endpoint based on the color change. 4.2.2 Reagents and materials
4.2.2.1 Potassium iodide.
4.2.2.2 Triazine.
4.2.2.3 Hydrochloric acid solution: 1+1.
4.2.2.4 Sodium thiosulfate standard titration solution: c(NazS2O,) is approximately 0.1 mol/L. 4.2.2.5 Starch indicator solution: 10 g/1. (The shelf life is two weeks). 4.2.3 Analysis steps
Weigh about 0.1g of the sample (accurate to 0.0002g) that has been dried at 105-110℃ to a constant mass, place it in a 250ml iodine volumetric flask, add 100ml of water to dissolve it, add 2g of potassium iodide, 10ml of trifluoromethane and 5ml of hydrochloric acid solution, shake well, place it in a dark place for 5min, titrate with sodium thiosulfate standard titration solution, add 2ml of starch indicator when it is close to the end point (the solution changes from brown red to light yellow), vigorously vibrate for 1min, and continue to titrate until the blue color of the water layer disappears. Perform a blank test in between.
4.2.4 Expression of analysis results
The content of sodium selenite (Na2Se().) expressed as mass percentage (X,) is calculated according to formula (1): X(%)=
4. 323(V -V2)a
(Vi-V2)c× 0. 043 23
The content of sodium selenite (in terms of Se) expressed as mass percentage (X,) is calculated according to formula (2): 1. 974(Vi-V2)c
(Vi-V,)cX0. 019 74
X2(%)=:
X 100=
Wherein: c--actual concentration of sodium thiosulfate standard titration solution, mol/L; VI--volume of sodium thiosulfate standard titration solution consumed by titration test solution, mL; V. ——Volume of sodium thiosulfate standard titration solution consumed in titrating the empty test solution, mL; (1)
(2)
m--mass of the sample (dry basis), g;
0.019 74-
HG 2937-- 1999
mass of sodium sulfite equivalent in grams to 1.00 mL of sodium thiosulfate standard titration solution [c(Na,S,O,)-1.000 mol/L,],
mass of selenium equivalent in grams to 1.00 mL of sodium thiosulfate standard titration solution [c(Naz2S,O,)=1.000 mal/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 is not more than 0.3% in terms of Na2SeO; 4.3 Determination of sweat loss
4.3.1 Instruments and equipment
4.3.1.1 Weighing bottle: 940mmX25mm
4.3.1.2 Electric constant temperature drying oven: The temperature can be controlled at 105~110℃. 4.3.2 Analysis steps
Weigh about 1g of sample (accurate to 0.0002g), place it in a weighing bottle that has been dried to constant mass at 105-110℃, place it in an electric constant temperature drying oven, and dry it at 105-110℃ to constant mass. 4.3.3 Expression of analysis results
The drying loss (X,) expressed as mass percentage is calculated according to formula (3): mlmz ×100 *
X,(%)=
Where m..mass of weighing bottle and sample before drying, g; m --~Weigh the bottle and sample mass after drying, g; m
Sample mass, g.
4.3.4 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 0.1%. (3)
4.4 Dissolution test
Weigh 1g of sample (accurate to 0.01g), put it in a test tube, add 10ml of water and dissolve it. The sample should be completely dissolved and the solution should be clear and transparent. 4.5 Determination of selenate and sulfate content
4.5.1 Summary of the method
Add sodium carbonate and hydrochloric acid to the sample and repeat. After evaporation, dissolve the residue with dilute acid, add barium chloride solution, and compare with standard turbidimetric solution.
4.5.2 Reagents and materials
4.5.2.1 Sodium carbonate.
4.5.2.2 Hydrochloric acid.
4.5.2.3 Hydrochloric acid solution: 1+10.
4.5.2.4 Ammonia solution: 1+1.
4.5.2.5 Barium chloride solution: 100g/L.
4.5.2.6 Sulfate standard solution: 1mL solution contains 0.1mg sulfate. 4.5.2.7 Litmus paper (red).
4.5. 3 Instruments and equipment
Porcelain evaporation tube: 50ml.
4.5.4 Analysis steps
Weigh (0.50±0.01)g of sample, place in porcelain evaporation tube, add 0.02g of sodium carbonate and 10ml of hydrochloric acid, and slowly evaporate the solution on a steam bath in a fume hood until dry. Rinse the porcelain evaporation tube with 5mL of hydrochloric acid and evaporate again until dry. Dissolve the residue with a mixed solution of 15ml of hot water and 1ml of hydrochloric acid, transfer the solution to a 50ml colorimetric tube, and neutralize it with ammonia solution until the red litmus paper turns blue. Add 176
HG2937—1999|| tt||1mL hydrochloric acid solution, 2mL barium chloride solution, add water to the scale, shake well, and place for 10 minutes before turbidity comparison. Its turbidity shall not be deeper than the turbidity produced by the standard turbidity solution.
The standard turbidity solution is to take 1.5ml of sulfate standard solution with a pipette, put it in a 50mL colorimetric tube, add 1ml hydrochloric acid solution, 2ml barium chloride solution, add water to the scale, and shake well. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 1t.
5.3 Determine the number of sampling units according to the provisions of 6.6 of GB/T6678-1986. When sampling, insert the sampler obliquely from the mouth of the packaging container to three-quarters of the solubility of the material layer for sampling. After mixing the collected samples, reduce them to no less than 500g according to the quartering method, and pack them in two clean and dry wide-mouth bottles with stoppers and seal them. A label is attached to the bottle, indicating: manufacturer name, product name, batch number, sampling date and name of the sampler. One bottle is used for inspection and the other is kept for three months for reference. 5.4 Feed grade sodium selenite shall be inspected by the quality inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all feed grade sodium selenite shipped out of the factory meets the requirements of this standard. 5.5 If one of the indicators in the inspection results does not meet the requirements of this standard, re-samples shall be taken from twice the amount of packaging for re-inspection. If even one indicator in the re-inspection results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 6 Marking and labeling
6.1 The packaging of feed grade sodium selenite shall be firmly and clearly marked, including: manufacturer name, address, product name, trademark, net content, batch number or production date, proof that the product quality meets this standard and this standard number and the "highly toxic" mark specified in GB190. 6.2 Each batch of feed grade sodium selenite shipped out of the factory shall be accompanied by a firm and clear label printed in accordance with the requirements of GB10648. 7 Packaging, transportation and storage
7.1 Two packaging methods are used for feed grade sodium selenite. 7.1.1 Cardboard barrel packaging: The inner packaging adopts polyethylene plastic film bags with a thickness of not less than 0.1mm; the outer packaging adopts cardboard barrels, the edges of which are reinforced with steel belts, and the thickness of the barrel top, cover and bottom plate is not less than 8mm. The net content of each barrel is 25kg. 7.1.2 Plastic bottle packaging: Plastic bottles are used for packaging, and the thinnest wall thickness shall not be less than 0.5mm, and the net content of each bottle is 1kg. A certain number of plastic bottles are packed into cartons, and their performance and inspection methods shall comply with the relevant provisions of GB/T15346. 7.2 When feed grade sodium selenite is packaged in cardboard barrels, the inner bag of the packaging is tied twice with nylon rope, or sealed with other equivalent methods, and the outer barrel is fastened with a steel belt hoop to fasten the barrel body and the barrel cover, and the latch is firmly inserted. When plastic bottles are used for packaging, the inner and outer covers must be tightly covered, pressed and tightened. 7.3 Feed grade sodium selenite should be stored in a cool, dry place and should not be stored together with other items. 7.4 Feed grade sodium selenite should not be damaged or inverted during transportation to prevent exposure to sunlight and rain. It is strictly forbidden to be transported together with other items. 8 Safety
8.1 This product is highly toxic and must be premixed and diluted before being added to feed in accordance with relevant regulations. It should also be sold and used in accordance with the management measures for highly toxic substances. 8.2 When using this product, work clothes, gloves and masks should be worn to avoid direct contact with the skin and inhalation of this product. 177Hydrochloric acid, slowly evaporate the solution to dryness on a steam bath in a fume hood. Rinse the porcelain evaporator with 5mL hydrochloric acid and evaporate it again. Dissolve the residue with a mixed solution consisting of 15ml hot water and 1ml hydrochloric acid, transfer the solution to a 50ml colorimetric tube, and neutralize it with ammonia solution until the red litmus paper turns blue. Add 176
HG2937—1999
1mL hydrochloric acid solution and 2mL barium chloride solution, add water to the scale, shake well, and let it stand for 10 minutes before turbidity comparison. Its turbidity shall not be deeper than the turbidity produced by the standard turbidity solution.
The standard turbidity solution is to take 1.5ml of sulfate standard solution with a pipette, place it in a 50mL colorimetric tube, add 1ml hydrochloric acid solution and 2ml barium chloride solution, add water to the scale, and shake well. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 1t.
5.3 Determine the number of sampling units according to the provisions of 6.6 of GB/T6678-1986. When sampling, insert the sampler obliquely from the mouth of the packaging container to three-quarters of the solubility of the material layer to take a sample. After mixing the collected samples, reduce them to no less than 500g according to the quartering method, and pack them in two clean and dry wide-mouth bottles with stoppers 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 for inspection and the other bottle is kept for three months for reference. 5.4 Feed-grade sodium selenite shall be inspected by the quality inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all feed-grade sodium selenite shipped from the factory meets the requirements of this standard. 5.5 If one of the indicators in the inspection results does not meet the requirements of this standard, re-sampling and re-inspection shall be carried out from twice the amount of packaging. If even one of the indicators in the re-inspection results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 6 Marks and labels
6.1 The packaging of feed grade sodium selenite shall be firmly and clearly marked, including: manufacturer name, address, product name, trademark, net content, batch number or production date, proof of product quality conforming to this standard and this standard number and the "highly toxic" mark specified in GB190. 6.2 Each batch of feed grade sodium selenite shipped shall be accompanied by a firm and clear label printed in accordance with the requirements of GB10648. 7 Packaging, transportation and storage
7.1 Feed grade sodium selenite is packaged in two ways. 7.1.1 Cardboard barrel packaging: The inner packaging adopts polyethylene plastic film bag with a thickness of not less than 0.1mm; the outer packaging adopts cardboard barrel, the edge of the barrel body is reinforced with steel belt, and the thickness of the barrel top, cover and bottom plate is not less than 8mm. The net content of each barrel is 25kg. 7.1.2 Plastic bottle packaging: Plastic bottle packaging is adopted, and the thinnest part of its wall thickness shall not be less than 0.5mm, and the net content of each bottle is 1kg. A certain number of plastic bottles are packed into cartons, and their performance and inspection methods shall comply with the relevant provisions of GB/T15346. 7.2 When feed-grade sodium selenite is packaged in cardboard barrels, the inner bag of the package shall be tied twice with nylon rope, or sealed with other equivalent methods, and the outer barrel shall be fastened to the barrel body and the barrel cover with a steel band hoop, and the latch shall be firmly inserted. When using plastic bottles for packaging, the inner and outer covers shall be tightly covered, pressed and tightened. 7.3 Feed-grade sodium selenite should be stored in a cool and dry place, and it is strictly forbidden to mix with other items. 7.4 During transportation, it is strictly forbidden to damage or invert the packaging of feed-grade sodium selenite to prevent sun exposure and rain. It is strictly forbidden to mix with other items. 8 Safety
8.1 This product is highly toxic and must be premixed and diluted before being added to the feed in accordance with relevant regulations, and it shall be sold and used in accordance with the management methods for highly toxic substances. 8.2 When using this product, work clothes, gloves and masks should be worn to avoid direct contact with the skin and inhalation of this product. 177Hydrochloric acid, slowly evaporate the solution to dryness on a steam bath in a fume hood. Rinse the porcelain evaporator with 5mL hydrochloric acid and evaporate it again. Dissolve the residue with a mixed solution consisting of 15ml hot water and 1ml hydrochloric acid, transfer the solution to a 50ml colorimetric tube, and neutralize it with ammonia solution until the red litmus paper turns blue. Add 176
HG2937—1999wwW.bzxz.Net
1mL hydrochloric acid solution and 2mL barium chloride solution, add water to the scale, shake well, and let it stand for 10 minutes before turbidity comparison. Its turbidity shall not be deeper than the turbidity produced by the standard turbidity solution.
The standard turbidity solution is to take 1.5ml of sulfate standard solution with a pipette, place it in a 50mL colorimetric tube, add 1ml hydrochloric acid solution and 2ml barium chloride solution, add water to the scale, and shake well. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 1t.
5.3 Determine the number of sampling units according to the provisions of 6.6 of GB/T6678-1986. When sampling, insert the sampler obliquely from the mouth of the packaging container to three-quarters of the solubility of the material layer to take a sample. After mixing the collected samples, reduce them to no less than 500g according to the quartering method, and pack them in two clean and dry wide-mouth bottles with stoppers 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 for inspection and the other bottle is kept for three months for reference. 5.4 Feed-grade sodium selenite shall be inspected by the quality inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all feed-grade sodium selenite shipped from the factory meets the requirements of this standard. 5.5 If one of the indicators in the inspection results does not meet the requirements of this standard, re-sampling and re-inspection shall be carried out from twice the amount of packaging. If even one indicator of the re-inspection results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 6 Marks and labels
6.1 The packaging of feed grade sodium selenite shall be firmly and clearly marked, including: manufacturer name, address, product name, trademark, net content, batch number or production date, proof of product quality conforming to this standard and this standard number and the "highly toxic" mark specified in GB190. 6.2 Each batch of feed grade sodium selenite leaving the factory shall be accompanied by a firm and clear label printed in accordance with the requirements of GB10648. 7 Packaging, transportation and storage
7.1 Feed grade sodium selenite is packaged in two ways. 7.1.1 Cardboard barrel packaging: The inner packaging adopts polyethylene plastic film bag with a thickness of not less than 0.1mm; the outer packaging adopts cardboard barrel, the edge of the barrel body is reinforced with steel belt, and the thickness of the barrel top, cover and bottom plate is not less than 8mm. The net content of each barrel is 25kg. 7.1.2 Plastic bottle packaging: Plastic bottle packaging is adopted, and the thinnest wall thickness shall not be less than 0.5mm, and the net content of each bottle is 1kg. A certain number of plastic bottles are packed into cartons, and their performance and inspection methods shall comply with the relevant provisions of GB/T15346. 7.2 When feed-grade sodium selenite is packaged in cardboard barrels, the inner bag of the package shall be tied twice with nylon rope, or sealed with other equivalent methods, and the outer barrel shall be fastened to the barrel body and the barrel cover with a steel band hoop, and the latch shall be firmly inserted. When using plastic bottles for packaging, the inner and outer covers shall be tightly covered, pressed and tightened. 7.3 Feed-grade sodium selenite should be stored in a cool and dry place, and it is strictly forbidden to mix with other items. 7.4 During transportation, it is strictly forbidden to damage or invert the packaging of feed-grade sodium selenite to prevent sun exposure and rain. It is strictly forbidden to mix with other items. 8 Safety
8.1 This product is highly toxic and must be premixed and diluted before being added to the feed in accordance with relevant regulations, and it shall be sold and used in accordance with the management methods for highly toxic substances. 8.2 When using this product, work clothes, gloves and masks should be worn to avoid direct contact with the skin and inhalation of this product. 177
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