Some standard content:
Chemical Industry Standard of the People's Republic of China
HG 2281 -- 92
Sodium bisulfite formaldehyde
(carving white block)
Published on 1992-06-01
Ministry of Chemical Industry of the People's Republic of China
Implemented on 1993-01-01
Chemical Industry Standard of the People's Republic of China
Sodium bisulfite formaldehyde (carving white block)
Subject Content and Scope of Application
HG 2281—92
This standard specifies the technical requirements, test methods, inspection rules, and requirements for labeling, packaging, transportation and storage of soft sulfuric acid hydrogen steel formaldehyde [Diaobai block].
This standard is applicable to sodium thioaldehyde hydrogen monoaldehyde (Diaobai block) obtained by zinc powder method, and its main use is as a discharge agent in the printing frame industry.
Molecular formula: NaHS0,·CH,0·2H,0
Relative molecular mass: 154.12 (according to the international relative atomic mass in 1989) 2 Reference standards
GB 601
3 Technical requirements
Chemical reagents Preparation of standard solutions for drop analysis (capacity analysis) Preparation of preparations and products used in chemical reagent test methods 3.1 Appearance: white block
3.2 Odor: no odor or a little leek odor. 3.3 Sodium formaldehyde sulfoxide should meet the requirements of the following table:
Sodium formaldehyde content (NaHSO4+CH2O·2H2O), %n,
Dissolved state
Sulfide
4 Test method
Determination of formaldehyde content in sodium bisulfite
4.1.1 Summary of method
First-class product
Qualified product
Soluble in water to show clear or slightly oily
Not black
After the formaldehyde solution conceals the impurity sulfite in the sample, the sodium bisulfate formaldehyde reacts quantitatively with the standard titration solution. 4.1.2 Reagents and solutions
4.1.2.1 Neutral formaldehyde solution
Preparation method: Add 5 drops of phenolic acid indicator solution (4.1.2.5) to 500mL of formaldehyde (GB685) solution (1+1), and then add sodium hydroxide solution (4.1.2.2) until the solution turns light red. 4.1.2.2 Hydroxide (GB629) solution: 10 No./L: Approved by the Ministry of Chemical Industry of the People's Republic of China on June 1, 1992 and implemented on January 1, 1993
HG 2281-92
4.1.2.3 Hydrochloric acid (GB 622) solution: 1 mol/L; 4.1.2.4 Iodine (GB675) standard titration solution: C (1/2I) = 0.1000 mol/L. Prepared and calibrated according to GB601. 4.1.2.5 Phenol (GB3039) ethanol solution: 10 g/L, prepared according to 4.5.22 of GB603. 4.1.2.6 Starch (HG3095) solution: 5g/L, prepared according to 4.5.20 of GB603. 4.1.3 Instruments and equipment
General laboratory instruments.
4.1.4 Analysis steps
After mixing the sample that has been quickly crushed into a diameter of about 0.4cm, weigh about 2g (concentrate to 0.0002g) and put it in a beaker, add 20mL of neutral formaldehyde solution (4.1.2.1), stir with a glass rod until it is completely dissolved, transfer to a 500mL volumetric flask, dilute to the scale with distilled water, and measure the hook. Take 25mL of this solution and place it in a 250mL conical flask, add 4mL of hydrochloric acid solution (4.1.*.3), and titrate with iodine standard titration solution (4.1.2.4). When it is close to the end point, add 5mL of starch indicator solution (4.1.2.6), and then titrate until the solution turns light blue. The indicator disappears within 30 5 seconds, which is the end point. 4.1.5 Expression and calculation of results
The mass percentage of formaldehyde in sodium hydrogen sulfate () is calculated as follows: X-
P cx 0. 038 53
m×500
-the volume of iodine standard titration solution consumed when measuring the sample, mL; where: -
c-the actual volume of iodine standard titration solution, mol/L; m-the mass of the sample, :
0. 038 53-with 1. 00 mL iodine standard titration solution [e [Mass of sodium formaldehyde,
-1) 1.000 401/L) is equivalent, the difference between the results of two determinations of hydrogen sulfite expressed in grams is not more than 0.5%, and the arithmetic mean of the parallel determination results is the determination result. 4.2 Determination of dissolution state
4.2.1 Instruments and equipment
General laboratory instruments.
4.2.2 Analysis steps
Weigh 1 g of the mixed sample, accurate to .1 g, and place it in a colorless test tube with a diameter of about 20 mm, add 20 mL of sugarcane water, shake and mix, and observe its dissolution state.
4.3 Determination of sulfide
4. 3. 1 Method summary
Alkaline lead acetate can react with sulfide to form black lead sulfide. 4.3.2 Reagents and solutions
4.3.2.1 Acetic acid (GB676):
4.3.2.2 Sodium hydroxide (GB629) solution: 100g/L; 4.3.2.3 Lead acetate (Pb(CH,CO0O)2·3H,O) (HG3--974) solution: 118g/L, take 11.8g of lead acetate and dilute it to 100㎡L, then add 2 drops of acetic acid for standby use, 4.3.2.4 Alkaline lead acetate solution: take about 0.5mL of lead acetate solution (4.3.2.3) and add sodium hydroxide solution (4.3.2.2) dropwise until the generated precipitate is well dissolved. This solution is prepared as needed. 3.3 Instruments and equipment
General laboratory instruments,
4.3.4 Analysis steps
HG 2281 — 92
Weigh 1g of the mixed sample, accurate to 0.1g, dissolve in 10mL of water, add 5 drops of alkaline lead acetate solution (4.3.2.3), no black color should appear,
S Inspection rules
5.1 Sodium bisulfate formaldehyde should be inspected by the quality supervision and inspection department of the manufacturer. The manufacturer should ensure that all products shipped meet the requirements of this standard. Each batch of sodium bisulfate formaldehyde shipped should be accompanied by a certificate of conformity in a certain format. 5.2 The user has the right to conduct quality inspections on the received sodium bisulfate formaldehyde in accordance with the provisions of this standard to check whether its quality meets the requirements of this standard.
5.3 Sampling method: take uniform products as one batch, the quantity of each batch shall not exceed 10t, and take samples from 5% barrels of each batch. The sampling of small batch products shall not be less than 2 barrels. The barrels shall still be sealed after sampling. 5.4 Quickly knock the sample into small pieces with a diameter of 1-1.5cm, mix and take out 100g, put them into a clean and dry colored glass bottle with a ground stopper, seal and store, stick a label on the bottle, indicate: manufacturer name, product name, batch number and sampling date, and send it to the inspection department for inspection.
5.5 If one indicator in the inspection result does not meet the requirements of this standard, a sodium bisulfite formaldehyde sample should be taken from twice the amount of packaging for re-inspection. If the result of the re-inspection shows that even if only one indicator does not meet the requirements of this standard, the whole batch of products cannot be accepted.
5.6 When the supply and demand parties have disputes over product quality and need arbitration, the arbitration institution can be selected by agreement between the two parties. During arbitration, the inspection shall be carried out according to the inspection methods specified in this standard. www.bzxz.net
6 Marking, packaging, transportation, storage
61 The packaging container shall be painted with a firm mark, including: manufacturer name, product name, trademark, standard number, quality grade, production date, batch number, net weight of the product, proof that the product quality meets the requirements of this standard and the editor of this standard. 6.2 The packaging barrel shall be accompanied by a certificate of conformity, which includes the manufacturer name, product name, batch number, production date, net weight of the product, proof that the product quality meets the requirements of this standard and the editor of this standard. 6.3 Sodium bisulfate formaldehyde is packaged in a large iron barrel lined with a plastic bag and sealed with a lid. The net weight of each barrel is 50kg. 6.4 During transportation, it should be lightly loaded and handled to prevent shock and water, so as to avoid damage to the iron barrel and affect the quality. 6.5 Sodium hydrogen sulfate formaldehyde should be packaged intact and stored in a dry and cool place. 6.6 The storage period of sodium hydrogen sulfate formaldehyde is 1 year. Due to its unstable chemical properties, the main content is allowed to decrease by 2% after 1 year.
Additional Notes:
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Shenyang Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by Shanghai Sulfuric Acid Factory. The main drafter of this standard is Yao Zuyin.
This standard adopts the Japanese Industrial Standard JISK1476-80 (35) "Sodium Bisulfite Series Dye Discharging Agent Bleaching Agent". From the date of implementation of this standard: the original Ministry of Chemical Industry Standard HG2-383---80 "Sodium Bisulfite Formaldehyde Drinking Sulphur Drum (White Block)" is invalid.
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