Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T2561—94
Industrial Sodium Methanol Methanol Solution
Published on February 9, 1994
Ministry of Chemical Industry of the People's Republic of China
Implemented on June 1, 1994
WChemical Industry Standard of the People's Republic of China
Industrial Sodium Methanol Methanol Solution
1 Subject Content and Scope of Application
HG/T2561—94
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation, storage, etc. of sodium methoxide methanol solution. This standard applies to the sodium methoxide methanol solution prepared by the reaction of methanol and sodium hydroxide and dehydration, and also applies to the sodium methoxide methanol solution generated by the reaction of methanol and metallic sodium.
Molecular formula: CH:ONa
Relative molecular mass: 54.02 (according to the international relative atomic mass in 1989) 2 Reference standards
GB190 Dangerous goods packaging markbzxZ.net
GB191 Pictorial mark for packaging, storage and transportation
Preparation of standard solution for titration analysis (volume analysis) of chemical reagents GB/T601
GB/T603
Preparation of preparations and products used in test methods for chemical reagents GB/T1250
Expression and determination methods of limit values GB/T6678
3 General rules for sampling of chemical products
GB/T6680 General rules for sampling of liquid chemical products 3 Technical requirements
3.1 Appearance: colorless to light yellow slightly turbid viscous liquid. 3.2 Industrial sodium methoxide methanol solution shall meet the requirements of Table 1: Table 1
Sodium methoxide content, %
Water content, %
4 Test method
27.5~31.0
The reagents and water used in this standard, unless otherwise specified, are analytically pure reagents and distilled water or water of equivalent purity. The standard solution for titration is prepared in accordance with the requirements of GB/T601 and GB/T603. The instrument is a general laboratory instrument. 4.1 Determination of sodium methoxide content
4.1.1 Principle of the method
The sodium methoxide in the sodium methoxide methanol solution decomposes into methanol and sodium hydroxide when it meets water, and the sodium hydroxide reacts quantitatively with a standard hydrochloric acid titration solution of known concentration.
Reaction equation:
Approved by the Ministry of Chemical Industry of the People's Republic of China on February 9, 1994 and implemented on June 1, 1994
W.bzsoso.coI4.1.2 Reagents and solutions
HG/T2561-94
-CH.OH+NaOH
CH.ONa+H0
NaOH+HC1-NaCI+H20
4.1.2.1 Standard hydrochloric acid titration solution: c(HCI)=0.5mol/L; 4.1.2.2 Methyl red indicator solution: 1g/L.
4.1.3 Analysis steps
Put 50mL of water in a 250mL conical flask, add 3 drops of methyl red indicator solution, and titrate with standard hydrochloric acid titration solution until the solution turns red.
Weigh about 2g of the sample (accurate to 0.0002g), place it in the above bottle and titrate with standard hydrochloric acid solution until the solution turns red. 4.1.4 Expression and calculation of results
The mass percentage of sodium methoxide Xi is calculated according to formula (1): X, - · 0. 054 02 × 1003. 0 .
Wherein: V——the volume of standard hydrochloric acid solution consumed by the titrated sample, mL; c——the actual concentration of standard hydrochloric acid solution, mol/L; m
——the mass of the sample, g;
0.05402——the mass of sodium methoxide expressed in grams equivalent to 1.00mL standard hydrochloric acid solution [c (HCI) = 1.000mol/L);
3.0——the mass ratio of 1 mol of water to 1 mol of sodium methoxide X2
——the percentage of water determined in 4.2.
Take the arithmetic mean of the results of two parallel determinations as the determination result, and the difference between the two parallel determination results shall not exceed 0.2%. 4.2 Determination of moisture
4.2.1 Principle of the method
The moisture present in the sample reacts quantitatively with the Karl Fischer reagent with a known water equivalent. Reaction equation:
H20+I2+SO2+3CHN+CHOH2CHN·HI+CH.HNSO,CHs4.2.2 Reagents and solutions
4.2.2.1 Methanol: H20<0.05% (m/m). If the water content of the reagent is greater than 0.05%, add about 50g of 5A molecular sieve to 500mL of methanol, plug the bottle, leave it overnight, and absorb the supernatant for use. 4.2.2.2 Pyridine: H20<0.05% (m/m). If the water content of the reagent is greater than 0.05%, add about 50g of 5A molecular sieve to 500mL of pyridine, plug the bottle, leave it overnight, and take the supernatant for use. 4.2.2.3 Preparation of Karl Fischer Reagent
Liquid A: Weigh 40g of iodine and add it to a stoppered brown glass bottle containing 1000mL of methanol. Shake it continuously to fully dissolve the iodine, let it stand for three days, and take the supernatant for use.
Liquid B: Take 400mL of methanol and 400mL of pyridine, place them in a dry reagent bottle, mix them, and pass sulfur dioxide in an ice bath to increase the weight to 90g. The prepared solution is placed in a dark place and can be used after 24 hours. 4.2.2.4 Standardization of Karl Fischer Reagent
Take 10mL of solution B and place it in a dry 50mL stoppered reaction bottle. Titrate with solution A to be standardized until it turns amber (ignore the consumption of solution A) under stirring. Then weigh 10-20mg of water and place it in the reaction bottle. Titrate with solution A to be standardized until the solution changes from light yellow to amber (or determine the end point by potentiometric method). 2
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4.2.2.5 The titer of solution A of Karl Fischer Reagent against water (g/mL) is calculated according to formula (2): T-mo ...WHG/T2561-94
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4.2.3 Analysis steps
(2)
Take 10mL of Karl Fischer reagent B solution and place it in a 50mL dry stoppered reaction bottle. Titrate with Karl Fischer reagent A solution to the endpoint (ignore the consumption) under stirring. Then weigh 1-2g of sample (accurate to 0.0002g), quickly add it to the reaction bottle, and titrate with Karl Fischer reagent A solution to the endpoint under stirring. 4.2.4 Determination of the endpoint
4.2.4.1 Visual inspection: The endpoint is when the solution changes from yellow to amber. 4.2.4.2 Potentiometric method: Take 10mL of Karl Fischer reagent B solution, inject it into the titration cell, and titrate with Karl Fischer reagent A solution until the pointer of the ammeter produces a large deflection and remains unchanged for 1 minute, which is the end point (ignoring the consumption). Then weigh 1-2g of sample (accurate to 0.0002g), quickly add it to the titration cell, and titrate with solution A until the pointer of the ammeter has the same large deflection as the pointer in the blank test, and remain unchanged for 1 minute, which is the end point.
4.2.5 Expression and calculation of results
Water content (mass percentage) X2 is calculated according to formula (3): T·V
Where: V--volume of sample A solution consumed in titration, mL; T--titer of Karl Fischer reagent A solution to water, g/mL;-mass of sample, g.
Take the arithmetic mean of the results of two parallel determinations as the determination result, and the difference between the results of two parallel determinations shall not exceed 0.05%. 5 Inspection rules
(3)
5.1 The methanol solution of sodium methoxide shall be sampled and inspected by the quality inspection department of the manufacturer. The manufacturer shall ensure that each batch of products leaving the factory meets the requirements of this standard. Each batch of products leaving the factory shall have a quality certificate in a certain format, which shall include the product name, manufacturer name, factory address, production date or batch number, net weight, and this standard number. 5.2 The user has the right to inspect and accept the product received in accordance with the inspection rules and test methods of this standard. 5.3 The batch size of the methanol solution of sodium methoxide shall not exceed 24t. 5.4 Sampling shall be carried out in accordance with the method specified in Article 6.6.2 of GB/T6678 and Chapter 2 of GB/T6680. The sampling volume shall not be less than 500mL. The sample shall be divided into two equal parts, placed in clean and dry glass bottles, and labeled. The label shall indicate the product name, batch number, sampling date and sampler. One bottle is for inspection and the other is kept for future reference. 5.5 The test results shall be determined according to the rounded value comparison method of GB/T1250. If one of the indicators in the test results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-testing. If even one of the indicators in the re-test results does not meet the requirements of this standard, the batch of products shall be unqualified.
When the supply and demand parties have objections to the product quality, they shall negotiate to resolve or ask the arbitration unit to conduct arbitration analysis. The arbitration analysis shall be carried out according to the test methods and inspection rules specified in this standard. 3
W.bzsoso.coI6 Marking, packaging, transportation, storage
HG/T2561-94
6.1 Marking: The packaging container shall indicate the product name, manufacturer name, factory address, production date or batch number, net weight and the flammable liquid mark, toxic mark, corrosive item mark in GB190, and the moisture-sensitive mark in GB191. 6.2 Packaging: Sodium methoxide methanol solution should be packaged in clean and dry packaging barrels or containers, with a net weight of 160 ± 0.5kg or 180 ± 0.5kg per barrel. Each package should be accompanied by the quality certificate specified in Article 5.1. 6.3 Transportation: Sodium methoxide methanol solution can be transported by various means of transportation. It should be protected from fire, heat, rain and moisture during transportation. 6.4 Storage: It should be placed in a ventilated, dry and cool place during storage, and should be protected from fire. 6.5 Under the transportation and storage conditions specified in this standard, the storage period of this product is three months from the time of leaving the factory. Additional notes:
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 technical jurisdiction of the Beijing Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard was drafted by Shanghai People's Pharmaceutical Factory. The main drafters of this standard are Zhu Xueyi, Zhang Yaohui and Zhang Xun. W.bzsoso.cO
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