This standard specifies the determination method of aluminum content in tin. This standard is applicable to the determination of aluminum content in tin. Determination range: 0.00030% to 0.0040%. GB/T 3260.7-2000 Chemical analysis method of tin Determination of aluminum content GB/T3260.7-2000 Standard download decompression password: www.bzxz.net

GB/T3260.7.--2000
This standard is a reconfirmation of (F13/T3260.7.-1982 "Chemical Analysis Method of Tin - Determination of Aluminum by Chrome Azure S Photometric Method": It clearly stipulates the sample weighing amount and test solution aliquoting in the tool, and makes editorial modifications. This standard complies with:
GB/T 1.1 1993
3 Guidelines for Standardization
Basic provisions
Part 1: Standard writing
Unit 1: Rules for drafting and expressing standards GB/T1.4-1988 Guidelines for Standardization
" Provisions for the preparation of chemical analysis method standards
G13/T【467-1978 General principles and general provisions for chemical analysis methods of metallurgical products GB/T7729-1987 General principles for spectrophotometric methods for chemical analysis of metallurgical products GB/T17433-1998 Chemical analysis of metallurgical products Basic terminology for analysis methods This standard replaces GB/T3260.7-1982 from the date of implementation. This standard is proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of the China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard is drafted by Yunnan Tin Company and Liuzhou Huaxi Group Co., Ltd. This standard is drafted by the Beijing Research Institute of Mining and Metallurgy. The main drafters of this standard are Liu Chun, Dai Hongwen and Guo Yulan. 80
1 Scope
National Standard of the People's Republic of China
Methods for chemical analysis of tin -Determination of aluminum contentWww.bzxZ.net
Methods for chemical analysis of tin -Determination of aluminum content This standard specifies the method for determining the aluminum content in tin. This standard is applicable to the determination of aluminum content in tin. Determination range: 0.00030%~～~0.0040%. 2 Summary of methods
GB/T 3260.7--2000
Replaces GB/T3260.7-1982
The sample is dissolved in aqua regia, and a large amount of tin is eliminated with hydrochloric acid and hydrogen peroxide. Then, a small amount of residual tin, iron, copper, etc. are masked with DL-cysteine ​​hydrochloride, ascorbic acid, thiourea, etc. In a pH 5.8-6.8 buffer solution, aluminum forms a complex with chrome azurool S and a nonionic surfactant (0OP). The absorbance is measured at a wavelength of 615nm on a spectrophotometer. In 50mL of the tested solution, a total of 0.25mg of iron is contained. 1.5mg arsenic, 10mg lead, 0.3mg tin, bismuth, 1mg antimony, copper, zinc are not disturbed.
3 Reagents
The water used for reagent preparation and analysis is double distilled water or deionized water. 3.1 Hydrochloric acid (pl.19g/mL), high-grade purity. 3.2 Nitric acid (pl.42g/ml), high-grade purity. 3.3 Hydrogen peroxide (30%), high-grade purity. 3.4 Hydrochloric acid (1+1).
3.5 Hydrochloric acid (1+20).
3.6 Ammonia water (1+1), high-grade purity.
3.7 Ammonia water (1+20), high-grade purity.
3.8 E water: Mix 1 volume of nitric acid (3.4) with 3 volumes of hydrochloric acid (3.1). 3.9 Chrome azure S solution (1g/L): weigh 0.1g of Chrome azure S and dissolve it in 50mL of ethanol, dilute it with water to 100mL, and mix. 3.10 Polyethylene glycol octylphenyl ether (OP) solution (1g/L). 3.11 Acetic acid-ammonium acetate buffer solution: weigh 300g of ammonium acetate and dissolve it in water, add 3mL of glacial acetic acid, and dilute it with water to 1000ml. Store in a plastic bottle.
Ascorbic acid solution (10g/L).
3.13 Thiourea solution (20g/1.).
3.14DI.-Cysteine ​​hydrochloride solution (10g/I.). 3.15 Thymol blue ethanol solution (1g/L). 3.16 Aluminum standard stock solution: weigh 0.1000g aluminum (≥99.99%), place in a 100ml beaker, add 10ml hydrochloric acid (3.4), heat slightly to dissolve completely, add 10ml hydrochloric acid (3.4), transfer to a 1000ml volumetric flask, dilute to scale with water, and mix. This solution was approved by the State Administration of Quality and Technical Supervision on 2000-08-28 and implemented on 2000-12:01
1 ml contains 100μg aluminum.
GB/T 3260. 7.--2000
3.17 Aluminum standard solution: weigh 10.00ml aluminum standard stock solution and place in a 500ml volumetric flask, add 10ml hydrochloric acid (3.1), dilute to scale with water, and mix. This solution contains 2ug aluminum in 1ml. 4 Analysis steps
4.1 Test sample
Weigh the sample according to Table 1, accurate to .001g. Table 1
Aluminum content, %
0. 000 30-~ 0. 001 4
0. 001 4 ~ 0. 002 8
≥ 0. 002 8 ~~ 0. 004 0
Test sample amount, g
Carry out 2 independent determinations and take the average value. 4.2 Blank test
Carry out a blank test along with the test sample.
4.3 Determination
Total volume of test solution, ml
Determination of total amount
Volume of sub-sample. ml
4.3.1 Place the test material (4.1) in a 100mL beaker and cover with table blood. Add 10mL aqua regia and warm it to dissolve completely. Remove table III and evaporate to nearly dryness. Add 2mL hydrochloric acid (3.1) and 1 drop of hydrogen peroxide and evaporate to nearly dryness. Repeat this operation 3 or 4 times and cool. Add 1ml hydrochloric acid (3.1), blow the wall of the cup with water, heat to dissolve the soluble substances, and cool. 4.3.2 Transfer the test solution into a 25ml volumetric flask with water and dilute to the mark, mix well. Transfer 10.00mL of the test solution into a 50ml volumetric flask.
Note: When the amount of aluminum in the test material is less than 14μg, the operation in 4.3.2 should be omitted. Use water to transfer all the test solution into a 50mL volumetric flask, and proceed from 4.3.3.
4.3.3 Add 1mL DL-cysteine ​​hydrochloride solution, 3mL ascorbic acid solution, 3 drops of thymol blue solution, and add ammonia water until the deep red color fades, then use ammonia water (3.7) and hydrochloric acid (3.5) to adjust the solution to just turn slightly red and add about 0.2mL of hydrochloric acid (3.5) in excess. Add 3ml. Shumai solution, 3mL chrome azuro blue S solution, 5mL OP solution, 5mL acetic acid-ammonium acetate buffer solution, dilute to the scale with water, and mix well. Put it in a hood for 30 min.
4.3.4 Transfer part of the test solution into a 0.5cm absorption dish, use the blank test solution with the sample as a reference, measure its absorbance at a spectrophotometric wavelength of 615nm, and find the corresponding aluminum content from the working curve. 4.4 Drawing of working curve
4.4.1 Take 0, 1.00, 2.00, 3.00, 5.00, 7.00mL of aluminum standard solution and place them in 50mL volumetric flasks respectively. Dilute with water to about 20mL, and proceed as per 4.3.3. 4.4.2 Under the same conditions as the test sample, measure the absorbance of the standard solution with the reagent blank as the reference. Draw the working curve with the aluminum content as the abscissa and the absorbance as the ordinate.
5 Expression of analysis results
Calculate the percentage of aluminum according to formula (1):
Where: V,---volume of the test solution, mL;
V,---total volume of the test solution, ml;
Al(%) = m -V. × 10=b
m-·The amount of aluminum found from the working curve, ug; 82
× 100
m—The mass of the sample, g.
GB/T 3260.72000
The result is expressed to four decimal places. If the aluminum content is less than 0.0010%, it is expressed to five decimal places. 6 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Aluminum content
0.000300.00050
0.000500.0010
0. 001 0~0. 002 0
0. 002 0-- 0. 004 0
Allowable difference
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