GB/T 8647.1-1988 Chemical analysis method for nickel - Determination of iron content by sulfosalicylic acid spectrophotometry GB/T8647.1-1988 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Nickel Chemical Analysis Method
Determination of Iron Content Sulfosalicylic Acid Spectrophotometric MethodNickel: Determination of Iron Content Sulfosalicylic Acid Spectrophotometric MethodThis standard is applicable to the determination of iron content in nickel. Determination range: 0.0008%～0.70%. UDC 669. 24
：543.062
GB 8647.1---88
This standard complies with GB1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". 1 Method Summary
The sample is dissolved in nitric acid, and in about 7 mol/L hydrochloric acid solution, iron and nickel are separated by extraction with a mixed solvent of 4-methyl-2-pentanone and isoamyl acetate, and then back-extracted with water. In an ammonia solution with a pH of 8.5 to 11, iron (II) and sulfosalicylic acid form a stable yellow complex, and its absorbance is measured at a wavelength of 420 nm on a spectrophotometer. 2 Reagents
2.1 Hydrochloric acid (p1.19 g/mL), high-grade purity. 2.2 Hydrochloric acid (3+2), high-grade purity.
2.3 Ammonium hydroxide (p0.90 g/mL).
2.4 Nitric acid (3+2), high-grade purity
2.5 Sulfosalicylic acid solution (10%).
2.6 Mixed extractant: 4-methyl-2-pentanone and isoamyl acetate are mixed in equal volumes. 2.7 Iron standard stock solution: Weigh 0.2000g iron powder (≥99.98%) and place it in a 250mL beaker, add 10mL aqua regia, heat to dissolve the iron powder completely, add 10mL sulfuric acid (p1.84g/mL) and evaporate until white sulfur trioxide smoke appears. After cooling, wash the surface blood and the wall of the beaker with water and add water to about 50mL, heat to dissolve the salts. Transfer the solution to a 1000mL volumetric flask, dilute with water to the mark, and mix. This solution contains 200μg iron in 1mL.
2.8 Iron standard solution: Transfer 50.00mL of iron standard stock solution (2.7) to a 500mL volumetric flask, dilute with water to the mark, and mix. This solution contains 20μg iron in 1mL.
3 Instruments
Spectrophotometer.
4 Analysis steps
4.1 Sample treatment
Place the sample in a clean 250mL beaker, add hydrochloric acid (2.2) to immerse the sample, heat and boil for 10 minutes, remove, discard the washing liquid, wash with water until the solution has no green color, discard the water layer and then wash twice with anhydrous ethanol, dry at about 110℃ for later use. 4.2 Sample quantity
Weigh the sample according to Table 1.
Approved by China National Nonferrous Metals Industry Corporation on January 11, 1988. 404
Implemented on January 1, 1989
Iron content, %
0. 000 8 -~0. 002wwW.bzxz.Net
>0. 002 ~ 0. 01
>0. 01 ~ 0. 05
>0. 05 ~0. 3
4.3 Blank test
Carry out a blank test together with the sample.
4.4 Determination
GB 8647.1--88
Weigh sample, 8
Dilution volume, ml.
Dispense test liquid.mi.
15, 00
4.4.1 Place the sample (4.2) in a 250mL beaker, slowly add 15mL nitric acid (2.4), cover with a watch glass, heat at low temperature to completely dissolve the sample, and evaporate to a thick slurry, add 20 mL of water, and heat slightly to dissolve the salts. 4.4.2 Transfer the solution into a 125mL separatory funnel (volume 20mL), wash the beaker several times with 30mL of hydrochloric acid (2.1), and combine the washings in the separatory funnel. For samples with an iron content greater than 0.01%, dilute the test solution according to Table 1 and place it in a 125mL separatory funnel. Add water to a volume of 20mL and add 30mL of hydrochloric acid (2.1). 4.4.3 Add 15mL of mixed extractant (2.6) to the separatory funnel, shake for 30s, let stand and separate, then place the aqueous phase in another separatory funnel, add 15mL of mixed extractant (2.6) to the aqueous phase and repeat the extraction once, discard the aqueous phase, and combine the organic phases. Add 15mL of hydrochloric acid (2.2) and shake and wash for 15s. After standing and separating, discard the aqueous phase and repeat the washing once. 4.4.4 Add 20mL of water to the organic phase, shake for 30s, let stand and separate, place the aqueous phase in a 50mL volumetric flask, then add 15mL of water to the organic phase 4, shake for 30s, let stand and separate, then combine the aqueous phases in the volumetric flask. 4.4.5 Add 5mL of sulfosalicylic acid solution (2.5) to a volumetric flask, neutralize with ammonium hydroxide (2.3) until the solution turns yellow and the excess is 2mL, dilute with water to the mark, and mix. Cool in running water until the solution is clear. Transfer part of the solution into a 3cm colorimetric III. 4.4.6 Take the blank solution accompanying the sample as a reference, measure its absorbance at a wavelength of 420nm on a spectrophotometer, and find the corresponding amount of iron from the working curve.
4.5 Drawing of working curve
Pipette 0, 0.50, 1.50, 3.00, 4.50, and 6.00mL of iron standard solution (2.8) and place them in a group of 50mL volumetric flasks respectively. Proceed as in 4.4.5. Take the reagent blank solution as a reference, measure its absorbance at a wavelength of 420nm on a spectrophotometer, and draw a working curve with the amount of iron as the abscissa and the absorbance as the ordinate. 5 Calculation of analysis results
Calculate the percentage of iron according to the following formula:
Fe(%) = m: V. X 10-6
where: m, the amount of iron found from the working curve, ug; V.-——total volume of test solution, mL;
V, …. fractionated test solution volume, mL;
6 Allowable difference
Sample volume, g.
GB8647.1—88
The difference in analysis results between experimental honeys should not be greater than the allowable difference listed in Table 2. Table 2
0. 000 8 ~ 0. 001 5
>0. 001 5 ~~ 0. 002 5
>0. 002 5 ~ 0. 005 0
> 0. 005 0 ~ 0. 015 0
>0. 015 0~0. 040 0
>0. 040~0. 150
>0. 15～0. 70
Additional remarks:
This standard is technically managed by Beijing Research Institute of Mining and Metallurgy. This standard was drafted by Beijing Research Institute of Mining and Metallurgy and Jinchuan Nonferrous Metals Company. This standard was drafted by Chengdu Electric Power Plant.
The main drafters of this standard are Deng Yangxiu, Liu Chunhua and Zhou Xiaolan. Allowable deviation
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB128-76 "Nickel Chemical Analysis Method" will be invalid. 406
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