GB/T 8647.6-1988 Chemical analysis of nickel - Flame atomic absorption spectrophotometric method for the determination of cadmium, cobalt, copper, manganese, lead and zinc
Some standard content:
National Standard of the People's Republic of China
Chemical analysis method of nickel
Determination of cadmium.cobalt, copper, manganese, lead and zinc contents-- Flame atomic absorption spectrophotometric methodUDC 669. 24
GB 8647. 6 88
This standard is applicable to the simultaneous determination of cadmium, cobalt, copper, manganese, lead and zinc contents in nickel, and is also applicable to the independent determination of one of the elements. The determination range is shown in Table 1:
Content, %
0. 000 2 ~ 0. 003
0. 001 ~0. 30
>0. 001 5~0. 007
This standard complies with GB1467.78 "General Principles and General Provisions for Standardization of Chemical Analysis Methods for Metallurgical Products". Content, %
0. 001 ~1. 00
0. 000 8 ~~ 0. 002
0. 000 8 ~~ 0. 008
This standard is equivalent to the international standard ISO6351--1985 "Metallic Nickel--Determination of Silver, Bismuth, Cadmium, Cobalt, Copper, Iron, Manganese, Lead and Zinc Content-Flame Atomic Absorption Spectrophotometry".
1 Method Summary
The sample is decomposed with nitric acid. In a dilute nitric acid medium, using an air-acetylene flame, the absorbance of each element is measured on an atomic absorption spectrophotometer at the wavelength listed in Table 2.
The standard solution should contain the same concentration of nickel matrix as the sample solution. Instructions for use:
1) The original international standard measurement range is:
Cd 0. 000 2% ~0. 002 5%, Co
0. 001% ~ 1. 00%,
Cu 0. 000 2% ~1. 00%, Mn 0. 000 5% ~~0. 20%, Pb 0. 000 5% ~ 0. 01%, Zn
0. 000 2% ~~ 0. 025%.
Approved by China National Nonferrous Metals Industry Corporation on January 11, 1988 420
Implemented on January 1, 1989
2 Reagents
Wavelength, nm
GB 8647.6
2.1 Nickel metal (containing 0.0001% of cadmium, cobalt, copper, manganese, lead and zinc respectively). 2.2 Cadmium, cobalt, copper, manganese, lead and zinc (>99.9%). 2.3 Nitric acid (1+1), high-grade purity,
2.4 Nitric acid (1+19), high-grade purity.
Content, %
Wavelength.nm
2.5Standard storage solutions of cadmium, cobalt, copper, manganese, lead and zinc: Weigh 1.00008 of cadmium, cobalt, copper, manganese, lead and zinc (2.2) respectively and place them in a red 400mL beaker, add 40mL nitric acid (2.3) to each, cover with a watch glass, heat until completely dissolved, slightly boil to drive off nitrogen oxides, remove, wash table III and the wall of the cup with water, and cool to room temperature. Transfer to 1000mL volumetric flasks containing 160mL nitric acid (2.3) respectively, dilute to scale with water, and mix. 1mL of the above solution contains 1mg of cadmium, cobalt, copper, manganese, lead and zinc respectively. 2.6 Mixed standard solution A: Take 20.00mL of cadmium, cobalt, copper, manganese, lead standard storage solution (2.5) and 10.00mL of zinc standard storage solution (2.5) respectively, place them in a 1000mL volumetric flask containing 160mL nitric acid (2.3), dilute to scale with water, and mix. This solution contains 20ug cadmium, cobalt, copper, manganese, lead and 10ug zinc in 1ml. 2.7 Mixed standard solution B: Take 50.00mL of cobalt, copper standard storage solution (2.5) and 5.00mL of zinc standard storage solution (2.5) respectively, place them in a 500mL volumetric flask, dilute to scale with water, and mix. This solution contains 100ug cobalt, copper and 10μg zinc in 1mL. 3 Instruments
Atomic absorption spectrophotometer, with hollow cathode lamps for cadmium, cobalt, copper, manganese, lead and zinc. Under the best working conditions of the instrument, those that can meet the following indicators can be used. Minimum sensitivity: The absorbance of the highest concentration standard solution used in the working curve should be no less than 0.40 (zinc, cadmium), 0.35 (copper, cobalt, manganese) and 0.30 (lead).
Linearity of working curve: Divide the working curve into five sections according to concentration. The ratio of the absorbance difference of the highest section to the absorbance difference of the lowest section should be no less than 0.85.
Minimum stability: The coefficient of variation of the absorbance obtained by measuring 11 times each of the highest concentration standard solution and the zero concentration solution in the working curve relative to the average absorbance of the highest concentration standard solution should be no more than 1.50% and 0.50%, respectively. The calculation of the stability coefficient of variation is shown in Appendix A (supplement).
Instrument working conditions are shown in Appendix B (reference). 4 Analysis steps
4.1 Sample quantity
Weigh the sample according to Table 3.
Content of measured elements, %
La, co, copper, manganese, lead ≤ 0.01
Zinc ≥ 0.005
Co, copper ≥ 0.01~0.25
4.2 Blank test
GB 8647.6-88
Sample volume, 8
Volume of nitric acid (2.3) added to the dissolved sample, mL
Nitric acid from the same batch used in the experiment: The zero concentration solution of standard solution 4.4.1.2 and 4.4.2.2 can be used as the blank of the sample with the same matrix concentration as the test solution.
Nitric acid from different batches used in the experiment: Weigh the metal nickel (2.1) according to Table 3 and perform a blank test together with the sample. 4.3 Determination
4.3.1 Place the sample (4.1) in a clean, uncorroded 500mL beaker. 4.3.2 Add enough water to cover the sample, and add nitric acid (2.3) in batches according to the requirements of Table 3 to dissolve the sample. Heat until completely dissolved, boil slightly to drive off nitrogen oxides, and evaporate to a thick slurry. Add 20mL nitric acid (2.3) and 100mL water, heat until the salts are completely dissolved, and cool to room temperature. 4.3.3 Transfer to a 200mL volumetric flask, dilute to the scale with water, and mix. 4.3.4 Use air-acetylene flame on an atomic absorption spectrophotometer, according to the wavelength in Table 2, and adjust to zero with nitric acid (2.4) at the same time as the standard solution series, measure the absorbance of the test solution, subtract the absorbance of the sample blank, and find the concentration of the corresponding element from the working curve. Note: When the cobalt or steel content is ≥0.25%, the test solution can be further diluted with nitric acid (2.4). The nickel content of the standard solution should be consistent with the nickel content of the test solution. 4.4 Drawing of working curve
4.4.1 Working curve for cadmium, cobalt, copper, manganese, lead ≤ 0.01%, zinc ≤ 0.005%. 4.4.1.1 Weigh 5.00 g of seven portions of nickel (2.1) into a 500 mL beaker, and transfer to a 200 mL volumetric flask according to the following operation in 4.3.2.
4.4.1.2 Use a burette to add 0.2.00, 5.00, 10.00, 15.00, 20.00, and 25.00 mL of mixed standard solution A (2.6) into a volumetric flask (4.4.1.1), dilute to the mark with water, and mix. 4.4.1.3 Measure the absorbance of the standard solution under the same conditions as the sample determination, and subtract the absorbance of the zero concentration solution. Draw the working curve with the concentration of the element to be measured as the horizontal axis and the absorbance as the vertical axis. 4.4.2 Working curve for cobalt, copper>0.01%, zinc≥0.005%. 4.4.2.1 Weigh 2.00g of seven portions of nickel (2.1) into a 400mL beaker, and transfer to a 200mL volumetric flask according to 4.3.2.
4.4.2.2 Use a burette to add 0.5.0, 10.0, 20.0, 30.0, 40.0 and 50.0mL of mixed standard solution B (2.7) into a volumetric flask (4.4.2.1), dilute to the mark with water, and mix. 4.4.2.3 Proceed as in 4.4.1.3.
5Calculation of analysis results
Calculate the percentage of the measured element according to the following formula: X(%) = c Vx10--
rWhere: X
-the measured element (Cd, Co, Cu, Mn, Pb, Zn); the concentration of the measured element found from the working curve, ug/mL; X100
V——the total volume of the test solution, mL,
the sample volume, g.
6Tolerance
GE 8647.6--88
The difference in analytical results between laboratories should not be greater than the allowable difference listed in Table 4. Table weight
0. 000 20--0. 000 40
0. 000 4 ~ 0. 001 2
>0. 001 2 ~0. 002 0
>0. 002 0~0. 003 0
0. 601 0 ~ 0. 002 0
>0. 002 0 ~ 0. 008 0
>0. 008~0. 015
>0. 015~~0. 080
>0. 08 ~~0. 20
>0. 20~0. 60
>0. 60~~1. 00
0. 001 0-~ 0. 002 5
>0. 002 5~- 0. 005 0
>0. 005 0 ~ 0. 015 0
>0. 015 0~0. 025 0
≥0. 025~~ 0. 060
>0. 060~0. 200
≥0.200～0.300
0. 000 8 ~ 0. 002 0
>0. 001 5~ 0. 003 0
>0. 003 0-0. 007 0
0. 000 8 ~~0. 001 2
>0. 001 2 ~0. 004 0
>0. 004 0 ~~ 0. 008 0
GB 8647.6-88
Appendix A
Calculation of coefficient of variation of stability
(Supplement)
The formula for calculating the coefficient of variation of the absorbance of the highest concentration standard solution and the zero concentration solution is as follows: S. bZxz.net
z(c -)
n -- 1
Wherein; S. -The coefficient of variation of the absorbance of the highest concentration standard solution; 0)
S. —The coefficient of variation of the absorbance of zero concentration solution relative to the average absorbance of the standard solution with the highest concentration; —The absorbance of the standard solution with the highest concentration; —The average absorbance of the standard solution with the highest concentration; 0—The absorbance of zero concentration solution;
0—The average absorbance of zero concentration solution; Number of measurements.
(AI)
(A2)
GB8647.6--88
Appendix B
Instrument working conditions
(reference)
The reference working conditions for measuring each element using the following atomic absorption spectrophotometer are as follows: Instrument model
WFX-1D
WFX-ID
Additional instructions:
Determination elements
This standard is under the technical jurisdiction of Beijing Research Institute of Mining and Metallurgy. Lamp current
Monochromator passband
This standard was drafted by Beijing Research Institute of Mining and Metallurgy and Jinchuan Nonferrous Metals Company. This standard was drafted by Beijing Research Institute of Mining and Metallurgy, Jinchuan Nonferrous Metals Company and Chengdu Electrometallurgy Plant. The main drafters of this standard are Yan Fenyang, Xin Hanji, Wang Yunming, Li Xianwei, Chen Longju and Li Jing. Burner height
Air flow: Acetylene flow
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB128-76 "Nickel Chemical Analysis Method" will be invalid. 425
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