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SN/T 1038-2020: (Import and export sodium metal inspection method)
Status: Valid SN/T 1038: Evolution and historical versions
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| SN/T 1038-2020 | English | 239 |
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(Import and export sodium metal inspection method)
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SN/T 1038-2020
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| SN/T 1038-2002 | English | 359 |
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Method for the determination of sodium metal for metal for import and export
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SN/T 1038-2002
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PDF similar to SN/T 1038-2020
Basic data | Standard ID | SN/T 1038-2020 (SN/T1038-2020) | | Description (Translated English) | (Import and export sodium metal inspection method) | | Sector / Industry | Commodity Inspection Standard (Recommended) | | Classification of Chinese Standard | H10/19 | | Classification of International Standard | 71.040.40 | | Word Count Estimation | 11,164 | | Date of Issue | 2020-08-27 | | Date of Implementation | 2021-03-01 | | Older Standard (superseded by this standard) | SN/T 1038-2002 | | Regulation (derived from) | General Administration of Customs Announcement No. 98 [2020] | | Issuing agency(ies) | General Administration of Customs | SN/T 1038-2020: (Import and export sodium metal inspection method)---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Method for the inspection of sodium metal for import and export
The People's Republic of China Entry-Exit Inspection and Quarantine Industry Standards
Replace SN/T 1038-2002
Import and export of sodium metal inspection method
2020-08-27 release
2021-03-01 implementation
Issued by the General Administration of Customs of the People's Republic of China
Foreword
This standard was drafted in accordance with the regulations given in GB/T 1.1-2009.
This standard replaces SN/T 1038-2002 "Import and Export Metal Sodium Inspection Methods".
Compared with SN/T 1038-2002, the main technical changes of this standard are as follows except for editorial changes.
--Added sampling;
-Added the determination of calcium content and potassium content determination by atomic absorption spectrophotometry.
This standard was proposed and managed by the General Administration of Customs of the People's Republic of China.
Drafting organizations of this standard. Yinchuan Customs of the People's Republic of China and Shanghai Customs of the People's Republic of China.
The main drafters of this standard. Zhang Kun, Wang Changjian, Xiao Qian, Liu Wenli, Sun Min, Sun Pubing.
The previous editions of the standard replaced by this standard are as follows.
Import and export of sodium metal inspection method
Warning. According to the provisions of Chapter 6 of GB 12268-2012, this product belongs to category 4, item 4.3, which emits flammable gas in contact with water
Be cautious when operating. The sample and some reagents used in this test method are toxic and corrosive, and the operator must be in a fume hood
Handle with care! If it splashes on the skin, it should be rinsed immediately. In severe cases, it should be treated immediately. When using flammable products, it is strictly forbidden to use an open flame for heating.
1 Scope
This standard specifies the inspection method of sodium metal for import and export.
This standard applies to the determination of sodium metal for import and export.
2 Normative references
The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article
Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.
GB/T 601 Preparation of Standard Titration Solution for Chemical Reagents
GB/T 602 Preparation of standard solutions for impurity determination of chemical reagents
GB/T 6678 General Rules for Sampling of Chemical Products
GB/T 6682 Analytical laboratory water specifications and test methods
GB/T 22379 -2017 Industrial Metal Sodium
GB 12268 -2012 List of Dangerous Goods
3 Sampling and general regulations
3.1 Sampling method
Determine the number of sampling units according to GB/T 6678.When sampling, randomly select a piece of metallic sodium from each barrel and quickly cut it out with a knife
(The amount of each piece should not be less than 50 g). The total amount of sampling is not less than 300 g. Divide into two clean and dry bottles pre-filled with white oil,
seal. Make a record in time when sampling, one bottle is used for inspection, and one bottle is kept for future reference.
3.2 General provisions
Unless otherwise specified, the reagents used are of analytical grade, and the water is the secondary water specified in GB/T 6682.The test papers are all precision test papers. test
The standard titration solution, impurity standard solution, reagents and products required in the test, unless other requirements are specified, shall be in accordance with GB/T 601,
Prepared according to GB/T 602.
4 Measurement method
4.1 Determination of sodium content
4.1.1 Method summary
The test solution in which sodium metal of known mass is dissolved, uses bromocresol green-methyl red as an indicator, and has a pH change of 5.1.With salt
For acid standard solution titration, the sodium content is calculated based on the consumption and concentration of the hydrochloric acid standard solution titration.
4.1.2 Materials and reagents
4.1.2.1 Hydrochloric acid (ρ=1.18 g/mL).
4.1.2.2 Hydrochloric acid standard titration solution. 0.1 mol/L.
4.1.2.3 95% ethanol.
4.1.2.4 Bromocresol green-methyl red indicator. 0.1% bromocresol green ethanol solution 0.2% methyl red ethanol solution (3 1).
4.1.2.5 Stainless steel tweezers. 25 cm.
4.1.2.6 Sample knife. stainless steel.
4.1.2.7 Pipette. 20 mL.
4.1.2.8 Filter paper. Qualitative filter paper (Φ=9 cm).
4.1.2.9 Electronic balance. Sensitivity 0.1 mg.
4.1.2.10 Volumetric flask. 1 000 mL.
4.1.2.11 Triangular beaker. 300 mL.
4.1.2.12 Erlenmeyer flask. 250 mL.
4.1.3 Analysis steps
After removing the metal sodium block from the sample vial with tweezers, quickly wipe off the oil on the surface of the sample with filter paper, and use the sample knife to remove the oil from the middle part
Cut off about 5 g of sodium lumps, quickly put them into the weighed weighing bottle, and weigh to the nearest 0.0002 g. Place the sodium block containing 100 mL of ethyl acetate
In the triangular beaker of alcohol, cover with a watch glass. After the sodium is completely dissolved, rinse the watch glass with 20 mL~30 mL of water to clean the sample.
Then transfer it to a 1000 mL volumetric flask, dilute it to the mark with CO2-free distilled water and shake it up (this solution can be used for calcium determination).
Use a pipette to draw 20 mL of the test solution, place it in a 250 mL Erlenmeyer flask, add 2 drops of bromocresol green-methyl red indicator, and mark with hydrochloric acid.
Titrate the quasi-titrated solution until the solution turns from green to dark red, boil for 2 minutes, and continue to titrate after cooling until the solution turns dark red again. Do at the same time
Blank test.
4.1.4 Calculation
The sodium content X1 (calculated as Na) expressed in mass fraction is calculated according to formula (1).
Note. Take the arithmetic mean of the parallel determination results as the determination result, and the absolute difference between the two parallel determination results shall not exceed 0.2%.
4.1.5 Precision
The precision is shown in Table 1.
4.2 Determination of calcium content
4.2.1 Complexometric titration
4.2.1.1 Method summary
Add a masking agent to the test solution to adjust the pH to above 12, and titrate calcium with EGTA complexation.
4.2.1.2 Materials and reagents
4.2.1.2.1 Potassium hydroxide solution. 25% aqueous solution is stored in a polyethylene bottle.
4.2.1.2.2 Triethanolamine solution. 14.
4.2.1.2.3 Calcein-thymolphthalein mixed indicator. Weigh 0.20 g of calcein and 0.16 g of thymolphthalein, and put them at 110 ℃ in advance.
The dried 10 g potassium chloride (analytical grade) is ground evenly, put into a ground bottle, and stored in a desiccator.
4.2.1.2.4 EGTA standard solution. 0.005 mol/L. Weigh 1.90 g ethylene glycol diethyl ether diamine tetraacetic acid, add 50 mL water, and add 1 mol/L dropwise
After the sodium hydroxide solution completely dissolves the reagents, dilute with water to 1,000 mL and shake well for calibration. If it is prepared with reference reagents, no calibration is required.
4.2.1.2.5 Calcium standard solution. 0.005 mol/L. Weigh 0.280 4 g benchmark calcium oxide (CaO) that has been burned at 1 000 ℃, and dissolve in less
Dilute to 1 000 mL with water in a volume of hydrochloric acid (1 1) and shake well.
4.2.1.2.6 Calibration. Draw 25 mL of calcium standard solution into a 300 mL Erlenmeyer flask, add 50 mL of water, and proceed according to the determination procedure.
4.2.1.2.7 Calculation. The concentration of EGTA standard solution is calculated according to formula (2).
4.2.1.3 Measurement procedure
Accurately draw 20 mL of the preparation solution, put it into a 250 mL Erlenmeyer flask, add about 50 mL water, 5 mL triethanolamine solution (1 4),
10 mL 25% potassium hydroxide solution, 0.1 g calcein-thymolphthalein mixed indicator, shake well, immediately use EGTA standard solution
Titrate to the end of the titration just after the green fluorescence disappears, and record the volume consumed by the titration.
4.2.1.4 Expression of analysis results
The calcium (Ca) content X2 expressed in mass fraction is calculated according to formula (3).
4.2.1.5 Precision
The precision is shown in Table 2.
4.3 Determination of chlorine content
4.3.1 Method summary
In an acidic medium, chlorine reacts with silver ions (Ag) to form a white precipitate, which is proportional to the chlorine content. With a standard turbidity fluid
The chlorine content can be quickly measured by the visual turbidimetric method.
4.3.2 Materials and reagents
4.3.2.1 Nitric acid (ρ=1.042 g/mL).
4.3.2.2 Silver nitrate. benchmark.
4.3.2.3 Sodium chloride. benchmark.
4.3.2.4 50 μg/mL chlorine standard solution. accurately weigh 1.648 8 g of standard sodium chloride and dilute to 1,000 mL with distilled water. Add the above
Accurately draw 5 mL of the solution and dilute to 100 mL with distilled water.
4.3.2.5 Silver nitrate solution (10%).
4.3.3 Analysis steps
Use a pipette to draw 10 mL of the preparation solution, place it in a triangular beaker, and adjust the pH to about 4 with nitric acid (4.3.2.1) (use
Precise pH test paper measurement), add 10 mL silver nitrate solution (10%) (4.3.2.5), dilute to 100 mL with water, mix well, transfer to a colorimetric tube,
Let stand for 5 min. Draw 10 mL of 50mg/mL chlorine standard solution (4.3.2.4), adjust the pH to about 4 with nitric acid (use precision pH test
Paper measurement), add 10 mL silver nitrate solution (10%) (4.3.2.5), dilute to 100 mL with water, mix well, transfer to a colorimetric tube, and let stand for 5
min. Observe and compare under a black background. The turbidity of the test solution shall not be greater than the standard turbidity of the 50 ppm chlorine standard solution (4.3.2.4).
4.4 Determination of iron content
4.4.1 Spectrophotometry
4.4.1.1 Method summary
4.4.1.2 Materials and reagents
4.4.1.2.1 95% ethanol.
4.4.1.2.2 Hydrochloric acid. 1 1.
4.4.1.2.3 Phenolphthalein indicator. 1 g/L.
4.4.1.2.4 Ammonia (ρ=0.88 g/mL).
4.4.1.2.5 Glacial acetic acid.
4.4.1.2.6 Sodium acetate.
4.4.1.2.7 o-phenanthroline solution. 0.1%. The solution should be kept away from light, and only colorless solutions can be used.
4.4.1.2.8 Iron standard solution. 1 mL contains 0.100 mg of iron. Weigh 0.143 0 g of ferric chloride (reference reagent) and dissolve in 10 mL
In concentrated hydrochloric acid, dilute with water to 1 000 mL and mix well.
4.4.1.2.9 Acetic acid-sodium acetate buffer solution (pH ≈ 4.5). Measure 60 mL of glacial acetic acid (4.4.1.2.5) and add sodium acetate (4.4.1.2.6)
50 g, diluted with water to 1000 mL.
4.4.1.2.10 Hydroxylamine hydrochloride solution. 10%, ready when used.
4.4.1.2.11 Spectrophotometer. with a cuvette with a thickness of 3 cm.
4.4.1.3 Analysis steps
4.4.1.3.1 Preparation of test solution
Use filter paper to carefully wipe off the oily substance on the sodium metal, cut a block of sodium metal with a mass of about 1 g from the middle part, clamp it with tweezers, and place it quickly.
Put it into a dry weighing bottle and weigh it with a reduction method to the nearest 0.001 g. Place the sample in a 300 mL beaker containing 40 mL ethanol,
Cover with a watch glass. After the sample is completely dissolved, add 40 mL~50 mL of water, add 2 drops of phenolphthalein indicator, and use hydrochloric acid (4.4.1.2.2) to drip to
The red disappears...
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