GB/T 4375.10-1984 Chemical analysis of gallium - Determination of zinc content by atomic absorption spectrophotometry GB/T4375.10-1984 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical analysis of galliumThe atomic absorption spectrophotometric method fonthe determination of zinc content
Methods for chemical analysis of galliumThe atomic absorption spectrophotometric method fonthe determination of zinc contentThis standard is applicable to the determination of zinc in gallium. Determination range: 0.00050～0.020%. UDC. 669.871 : 543
.42 :546.47
GB 4375.10—84
This standard complies with GB1467-78 "General Principles and General Provisions for Standards of Chemical Analysis Methods for Metallurgical Products". 1 Method Summary
The sample is decomposed with nitric acid and hydrochloric acid, and the nitric acid is driven out with hydrochloric acid. In 7N hydrochloric acid solution, gallium is extracted and separated with isopropyl ether, and then zinc is determined with an air-acetylene flame at a wavelength of 213.9nm on an atomic absorption spectrophotometer. 2 Reagents
2.1 Nitric acid, high-grade pure (specific gravity 1.42). 2.2 Hydrochloric acid, high-grade pure (specific gravity 1.19). 2.3 Hydrochloric acid (10+7).
2.4 Isocyanate: First, wash with 10% hydroxylamine hydrochloride solution or 20% ammonium ferrous sulfate solution in a separatory funnel to remove peroxides, then transfer to a distillation flask, distill and purify in a water bath at 80℃, and collect the fraction at 67-69℃. Then saturate with hydrochloric acid (2.2). 2.5 Zinc standard stock solution: Weigh 1.000g pure zinc (more than 99.9%) and dissolve in 50ml hydrochloric acid (1+1). Cool, transfer to a 1000ml volumetric flask with water, dilute to the mark, and mix. This solution contains 1.0mg zinc in 1ml. 2.6 Zinc standard solution: Transfer 50.00ml zinc standard storage solution (2.5) to a 500ml volumetric flask, dilute to the mark with water, and mix. This solution contains 100μg zinc in 1ml.
3 Instruments
Atomic absorption spectrophotometer, equipped with an air-acetylene burner and a zinc hollow cathode lamp. The atomic absorption spectrophotometer used should meet the following indicators: Minimum sensitivity: The absorbance of the highest concentration standard solution of the arithmetic difference concentration standard solution used in the curve drawing should not be less than 0.500. 1. Linearity of the curve drawing: In the arithmetic difference concentration standard solution, the difference in absorbance between the highest and second highest concentration standard solutions should not be less than 0.7 times the difference in absorbance between the lowest concentration standard solution and the zero concentration solution. Minimum stability: 1. The coefficient of variation of the absorbance obtained by multiple measurements of the highest concentration standard solution and the zero concentration solution used in the curve relative to the average absorbance of the highest concentration standard solution should be less than 1.1% and 3.2% respectively. The calculation of the coefficient of variation in the minimum stability is shown in Appendix A (Supplementary).
The operating condition parameters of the WYX-401 atomic absorption spectrophotometer are shown in Appendix B (Reference). 4 Analysis steps
4.1 Determination quantity
Weigh two samples for determination and take the average value. Issued by the National Bureau of Standards on April 30, 1984
Implementation on April 1, 1985
4.2 Sample quantity
Weigh the sample according to Table 1.| |tt||Most, %
0.00050~0.0010
-0.0010~0.020
4.3 Blank test
Carry out a blank test with the sample.
GB4375.10-84
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4.4 Determination
4.4.1 Place the sample (4.2) in a 50ml beaker, add 1.5ml nitric acid (2:1), cover the beaker, and leave it for 30min. Add 3ml hydrochloric acid (2.2), and after the violent reaction stops, heat it on an electric furnace at about 120℃ until the sample is completely dissolved, evaporate to nearly F, then add 2ml hydrochloric acid (2.2), and continue Evaporate to nearly 1 to drive off most of the nitric acid. Wash the dish and the wall of the cup in Table III with 4 ml of hydrochloric acid (2.3), heat slightly to dissolve the salts, and cool.
4.4.2 Transfer the solution (4.4.1) to a 25 ml separatory funnel, wash the wall of the cup twice with 1 ml of hydrochloric acid (2.3), and add the washing liquid to the separatory funnel. Add 10 ml of isopropyl ether (2.4), shake for 2 minutes, let stand and separate, transfer the aqueous phase to a 25 ml volumetric flask [when the sample size is 0.2 g, transfer the aqueous phase to a 50 ml volumetric flask and add 2.5 ml of hydrochloric acid (2.2)], dilute with water to the scale, and mix well. 4.4.3 Spectrum the solution (4.3 and 4.4.2) on the original absorption spectrophotometer at a wavelength of 213.9n m, use air-acetylene flame, adjust the zero point with reagent blank solution, measure its absorbance, and find the corresponding zinc concentration from the I working curve. 4.5 "Working curve drawing
4.5.1 Take 0, 0.05, 0.10, 0.20, 0.30, 0.40, 0.50ml zinc standard solution (2.6), respectively put it into a group of 50ml volumetric flasks, add 5ml hydrochloric acid (2.2) to each, dilute with water to the scale, and mix. 4.5.2 Put the solution (4.5.1) on the original absorption spectrophotometer at a wavelength of 213.9nm, use air-acetylene flame, adjust the zero point with reagent blank solution, and measure its absorbance. Draw a working curve with zinc concentration as the horizontal axis and absorbance as the vertical axis. 5 Calculation of analysis results
Calculate the percentage of zinc by the following formula:
Zn(%)):
(C2-C)V
mg×106
Wherein: C2—Zinc concentration of the sample solution obtained from the curve, μg/ml;
V—Volume of the solution to be tested, ml;
ma—Sample amount, g.
6 Allowable Difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. 305
0.0005~0.0008
0.0008 ~ 0.0020
0. 0020 ~ 0.0050
0.0050 - 0.0080
0.008~0.020
GB4375.10—84
GB 4375.10—84
Appendix A
Calculation of the minimum stability coefficient of variation
(Supplement)
The formula for calculating the coefficient of variation of the absorbance readings of the highest concentration standard solution and the zero concentration solution is as follows: S.=
Where: Sc-
(O-0)2
-the percentage coefficient of variation of the absorbance of the highest concentration standard solution; - the absorbance of the highest concentration standard solution;
-the average value of the absorbance of the highest concentration standard solution:; number of measurements,
-the percentage coefficient of variation of the absorbance of the zero concentration solution; O—absorbance of the zero concentration solution;
-the average value of the absorbance of the zero concentration solution.
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Operating conditions
Additional instructions:
GB 4375.10--84
Appendix B
Working conditions parameters of WYX-401 atomic absorption spectrophotometer (reference)
This standard was proposed by China Nonferrous Metals Industry Corporation. Lamp current
This standard was drafted by the Nonferrous Metals Research Institute of China Nonferrous Metals Industry Corporation. The main drafter of this standard is Wang Shu'e. wwW.bzxz.Net
Air flow
B commutation
Flow rate scale
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