GB/T 4373.1-1984 Chemical analysis method for arsenic Potassium bromate volumetric method for determination of arsenic content GB/T4373.1-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of arsenic
Determination of arsenic content by potassium bromate volumetric method
Methods for chemical analysis of arsenicThe potassium bromate volumetric methodfor the determination of arsenic contentThis standard is applicable to the determination of arsenic content in arsenic. Determination range: 98.00～99.80%. This standard complies with GB1467-78 "General Principles and General Provisions of Standards for Chemical Analysis Methods of Metallurgical Products". 1 Method Summarybzxz.net
UDC 669.778: 543
.24:546.19
GB4373.1-—84
The sample is heated and dissolved in concentrated sulfuric acid, and after boiling with water, methyl orange is used as an indicator and titrated with potassium bromate standard solution until the solution becomes colorless as the end point. The arsenic content is calculated from the volume of potassium bromate standard solution consumed, and the net arsenic content is obtained after deducting the arsenic content equivalent to the antimony content in the sample. 2 Reagents
2.1 Sulfuric acid (specific gravity 1.84).
2.2 Nitric acid (1+4).
2.3 Urea solution (10%).
2.4 Methyl orange solution (1%). Use after filtering. 2.5 Potassium bromate standard solution: Weigh 3.033g potassium bromate and 3.0g potassium bromide, place in a beaker, dissolve with a small amount of water, transfer to a 1000ml volumetric flask, dilute with water to the scale, mix well, and calibrate after leaving for two days. Calibration: Weigh about 0.53g (accurate to 0.0001g) of arsenic trioxide (99.99%) in three portions and place them in = 400ml beakers 1. Cover the table III, add 20ml sulfuric acid (2.1), heat on the electric stove to dissolve, continue heating for 10min, cool, rinse the table blood and the cup wall with a small amount of water, add 100ml water, and heat on the electric stove until boiling. Move to the electromagnetic stirrer, remove the table dish, add 5ml nitric acid (2.2), 5ml urea solution (2.3) under constant stirring, add 95ml potassium bromate standard solution (2.5) from the 100ml burette, add 2-3 drops of phenoxy orange solution (2.4), and then titrate drop by drop until the color of the solution disappears. Calculate the titer of potassium bromate standard solution to arsenic according to formula (1) and take the average value: T =
X 0.7574.
--1ml potassium bromate standard solution is equivalent to the amount of arsenic, g, formula t: T
-the amount of arsenic trioxide weighed, g,
-the volume of potassium bromate standard solution consumed during calibration, m1 conversion factor for arsenic trioxide to arsenic. 0.7574
If the extreme difference of the three titers is greater than 6×10-6g, recalibration should be carried out. 3 Samples
3.1 The sample must be sieved with an 80-month sieve, and the diameter of the sieve should not be greater than 2mm. 3.2 After processing, the sample is stored in a desiccator and weighed for analysis on the same day, and the sample is weighed according to the ratio of 3:1 between the sieve and the sieve. ：National Bureau of Standards 1984-04-30 Issued
1985-0401 Implementation
Analysis steps
4.1 Determination quantity
GB 4373.1--84
Weigh two samples for determination and take the average value. 4.2 Sample quantity
Weigh about 0.4g sample, accurate to 0.0001g. 4.3 Determination
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Put the sample (4.2) in a 400ml beaker, add 20ml sulfuric acid (2.1), cover with Table III, heat on an electric furnace to dissolve, continue heating for 10 minutes, and cool. Wash Table III and the wall of the cup with a small amount of water, add 100ml water, and heat on an electric furnace to boiling. Move to the electromagnetic stirrer, remove Table III, add 5 ml nitric acid (2.2), 5 ml urea solution (2.3) under continuous stirring, add 95 ml potassium bromate standard solution from a 100 ml burette, add 2-3 drops of methyl orange solution (2.4), and titrate drop by drop until the color of the solution disappears. 5 Calculation of analysis results
Calculate the percentage of arsenic according to formula (2):
As (%) =TV
×100-Sb (%) ×0.6154
Formula t: 1 ml potassium bromate standard solution is equivalent to the amount of arsenic,; V
-the volume of potassium bromate standard solution consumed when titrating the test solution, ml; Sb%-the percentage content in the sample;
-the sample amount, g;
conversion factor for arsenic.
The analysis results are expressed to two decimal places. 6 Allowable Difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Arsenic
98.00 ~ 99.80
Additional Notes:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Hunan Shuikoushan Mining Bureau. This standard was drafted by the Research Institute of Hunan Shuikoushan Mining Bureau. The main drafters of this standard were Sun Xiaohui and Liu Binbin. 294
+ (2)
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