GB/T 8647.4-1988 Chemical analysis of nickel - Molybdenum blue spectrophotometric method for the determination of phosphorus content

GB/T 8647.4-1988 Chemical analysis method for nickel - Determination of phosphorus content by molybdenum blue spectrophotometry GB/T8647.4-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Nickel Chemical Analysis Method
Determination of phosphorus content- Molyhdenum blue spectrophotometric method
Nickel- Determination of phosphorus content- Molyhdenum blue spectrophotometric method This standard applies to the determination of phosphorus content in nickel. Determination range: 0.0005%~0.03%. UDC 669.24
GB8647.4-88
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, phosphorus is oxidized with potassium permanganate, and the phosphomolybdic heteropolyacid complex formed by phosphorus (V) and ammonium molybdate in an acidic solution is extracted with a mixed solvent of n-butanol-chloroform, reduced to phosphomolybdenum blue with stannous chloride, and its absorbance is measured at a wavelength of 620nm on a spectrophotometer.
2 Reagents
2.1 Nitric acid (1+1), high-grade pure. www.bzxz.net
2.2 Perchloric acid (1+1).
2.3 Perchloric acid (1+9).
2.4 Ammonium molybdate solution (10%): Weigh 10g high-grade pure ammonium molybdate (NH)Mo,0,·4H0] and dissolve it in 80mL hot water, cool, dilute with water to 100mL, mix, filter and use. 2.5 Stannous chloride solution (4%): Weigh 4g stannous chloride (SnCl2H.0) and add 20mL hydrochloric acid (p1.19g/mL) to dissolve, dilute with water to 100mL, mix. Prepare when using. 2.6 Potassium permanganate solution (3%).
2.7 n-Butanol.
2.8 Mixed extractant: Mix three parts of chloroform with one part of n-butanol. 2.9 Phosphorus standard stock solution: Weigh 0.7370g potassium dihydrogen phosphate (K,HPO·3H.0) and dissolve it in water, transfer it into a 1000mL volumetric flask, dilute it to the mark with water, and mix it. 1mL of this solution contains 100μg phosphorus. 2.10 Phosphorus standard solution: Transfer 10.00mL of phosphorus standard stock solution (2.9) into a 500mL volumetric flask, dilute it to the mark with water, and mix it. 1mL of this solution contains 2ug phosphorus.
3 Instruments
Spectrophotometer.
4 Analysis steps
4.1 Sample quantity
Weigh the sample according to Table 1.
Approved by China National Nonferrous Metals Industry Corporation on January 11, 1988, and implemented on January 1, 1989
Amount, %
0. 000 5 ~ 0. 001 5
0. 001 5 ~ 0. 003
>0. 003~0. 006
>0. 006-- 0. 015
>0. 015~0. 03
4.2 Blank test
Carry out a blank test together with the sample.
4.3 Determination
GB 86 47. 4 -- 88
Sample amount, name
Dilution volume, mL
Volume of test solution to be taken. mL
4.3.1 Place the sample (4.1) in a 250mL beaker, slowly add 15mL nitric acid (2.1), 2~4 drops of potassium permanganate solution (2.6), and heat slightly to dissolve the sample completely.
Note: Add 1 drop of potassium permanganate solution (2.6) directly to the sample. 4.3.2 After the solution has cooled, add 10mL perchloric acid (2.2), heat and evaporate until thick white perchloric acid smoke appears, cool, add 30mL water, and stir to dissolve the salts.
4.3.3 Transfer the solution to a 125mL separatory funnel and add water to 50mL. For samples with a phosphorus content greater than 0.006%, dilute the test solution according to Table 1 and place it in a 125mL separatory funnel, add perchloric acid (2.3) to 50mL. 4.3.4 Add 3mL ammonium molybdate solution (2.4) to the separatory funnel, shake well, and let stand for 10 minutes. 4.3.5 Add 2mL of n-butanol (2.7) and shake for 1min. Add 15mL of mixed extractant (2.8) and shake for 2min. After standing and stratifying, put the organic phase into a 50mL volumetric flask. Add 15mL of mixed extractant (2.8) to the aqueous phase and shake for 2min. After standing and stratifying, combine the organic phases into a volumetric flask.
4.3.6 Add 3-4mL of n-butanol (2.7) to the volumetric flask, add 4 drops of stannous chloride solution (2.5), dilute to the scale with n-butanol (2.7), mix well, let stand for 15-20min, and transfer part of the solution into a dry 2cm colorimetric III. 4.3.7 Use the blank solution accompanying the sample as a reference, measure its absorbance at a wavelength of 620nm on a spectrophotometer, and find the corresponding phosphorus content from the working curve.
4.4 Drawing of working curve
4.4.1 Take 0, 2.00, 4.00, 6.00, 8.00, 10.00mL of phosphorus standard solution (2.10) and place them in a set of 125mL separating funnels respectively. Add perchloric acid (2.3) to 50mL. Then proceed as per 4.3.4 to 4.3.6. Take the reagent blank solution as reference and measure its absorbance at a wavelength of 620nm on a spectrophotometer. Draw the working curve with phosphorus content as the horizontal axis and absorbance as the vertical axis. Calculation of analysis results
Calculate the percentage of phosphorus according to the following formula:
Wherein: ml
P(%) = m:V:X10- × 100
Phosphorus content found from the working curve, duo: total volume of test solution, mL;
Volume of test solution taken, mL;
Sample volume, g.
Allowable difference
GB 8647.4-88
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
0. 000 5~ 0. 000 8
0. 000 8~-0. 001 5
0. 001 5~ 0. 002 5
0. 002 5 ~~ 0. 005 0
0. 005 ~~ 0. 015
0. 015~0. 03
Additional remarks:
This standard is under the technical jurisdiction of 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. This standard is equivalent to the Soviet standard TOCT13047.5-81 "Nickel analysis method - determination of phosphorus content - molybdenum blue spectrophotometry". From the date of implementation of this standard, the former Ministry of Metallurgical Industry standard YB128-76 "Nickel chemical analysis method" will be invalid.
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