This standard is applicable to the determination of calcium oxide in fluorescent grade yttrium oxide and europium oxide. Determination range: 0.000 30% to 0.005 0%. This standard complies with GB 1467-1978 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". GB/T 8762.2-1988 Determination of calcium oxide content in fluorescent grade yttrium oxide and europium oxide by nitrous oxide-acetylene flame atomic absorption spectrophotometry GB/T8762.2-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of calcium oxide content in fluorescent grade oxidation and oxidation
Determination of nitrous oxide acetylene flame
Atomic absorption spectrophotometric method
Yttrium oxide and europium oxide of phosphorus grade-.Determination of calcium oxide content - N,O - C,H,flame atomic absorption spectrophotometric methodUDC 661. 866+661
-866.1:543.063
GB 8762.282
This standard is applicable to the determination of calcium oxide in fluorescent grade oxidation and oxidation. Determination range: 0.00030%~~0.0050% This standard complies with GB1167-78 "General Principles and General Provisions for Chemical Analysis Methods of Metallurgical Products". 1 Method Summary
The sample is decomposed with hydrochloric acid. In 2% (V/V) hydrochloric acid medium, with matrix yttrium oxide or platinum oxide as the release agent, the standard addition method is used to determine calcium oxide at the wavelength of 422.7nm of the original absorption spectrophotometer with a nitrous oxide-acetylene flame. 2 Reagents
2.1 Hydrochloric acid. Super pure (1.19), purified by distillation. 2.2 Hydrochloric acid (1+1).
2.3 Triple ion exchange water.
2.4 Calcium oxide standard stock solution: Weigh 0.1784g of calcium ferroate (99.99%) that has been pre-dried at 105~110℃ for 2h and cooled to room temperature in a desiccator, place it in a 300mL beaker, add 20mL of water (2.3), add hydrochloric acid (2.J) dropwise until it is completely dissolved and filter through 10ml. Boil to drive off carbon monoxide. After cooling, transfer to a 1000mL volumetric flask, dilute to scale with water (2.3), and mix. This solution contains 0.1mg calcium oxide in 1mL.
2.5 Calcium oxide standard solution: Transfer 50.00mL of calcium oxide standard storage solution (2.4) to a 500mL volumetric flask, add 5ml of hydrochloric acid (2.1), dilute to scale with water (2.3), and mix. This solution contains 10μg calcium oxide in 1mL. 3 Instruments
Atomic absorption spectrophotometer, equipped with nitrous oxide-acetylene burner and calcium 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 working curve should not be less than 0.350. Working curve linearity: In the standard solution of equal concentration, the difference in absorbance between the highest and the second highest concentration standard solution should not be less than 0.9 times the difference in absorbance between the lowest concentration standard solution and the zero concentration solution. Minimum stability: The coefficient of variation of the absorbance obtained by multiple measurements (not less than 11 times) 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 1.0% and 0.3%, respectively. The calculation of the minimum stability + coefficient of variation is shown in Appendix A.
The working condition parameters of the GGX-2 atomic absorption spectrophotometer are shown in Appendix B. China Nonferrous Metals Industry Corporation approved on February 4, 1988 and implemented on February 1, 1989
4 Analysis steps
Quantity of determination
GB 8762.2--88
The same sample should be determined twice independently and the average value should be taken. 4.2 Sample quantity
Weigh the sample according to Table 1.
Calcium oxide content
0. 000 30 0. 001 0
>0. 001 0 ~~ 0. 003 0
>0. 003 0 ~ 0. 005 0
4.3 Blank test
Sample volume
Carry out a blank test together with the sample, and calculate the blank value by the standard addition method. The calculated blank value shall not be greater than 0.05ug/mL. 4.4 Determination
4.4.1 Place the sample (4.2) in a 50mL beaker, add hydrochloric acid (2.2) according to Table 1, cover with surface III, heat slowly to dissolve, and evaporate to nearly dryness. Remove and cool slightly, and rinse surface III and the beaker wall with water (2.3). Heat to dissolve the salts, remove and cool to room temperature, transfer to a 50 mL volumetric flask, dilute to scale with water (2.3), and mix. 4.4.2 Transfer 4 5 mL portions of the test solution (4.4.1) to 10 mL volumetric flasks, add 0.0, 0.50, 1.00, and 1.50 mL of calcium oxide standard solution (2.5) to each, dilute to scale with water (2.3), and mix. 4.4.3 Place the solution (4.4.2) at a wavelength of 122.7 nm in an atomic absorption spectrophotometer, use a difluoroacetylene flame, adjust to zero with water (2.3), and measure its absorbance.
4.4.4 Draw a curve with the calcium oxide concentration as the horizontal axis and the corresponding absorbance as the vertical axis. The concentration value at the intersection of the horizontal axis and the curve when the curve is extended in the reverse direction is the calcium oxide concentration of the solution being tested. 5 Calculation of analysis results
Calculate the percentage of calcium oxide according to the following formula: c,
Cao(%) =
max100
Wherein: ci
Calcium oxide concentration of blank solution obtained by standard addition method, g/mL; -Calcium oxide concentration of tested solution obtained by standard addition method, ug/mL; -Volume of tested solution, mL;
Sample volume, 8.
6 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Calcium oxide content
0. 000 30 ~~0. 001 0
>0. 001 0~0. 003 0
≥0. 003 0~ 0. 005 0
Allowance
GB8762.2—88
Appendix A
Calculation of minimum stability coefficient of variation
(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: Sa
Wherein: S. Percent variation coefficient of absorbance of the highest concentration standard solution; absorbance of the highest concentration standard solution;
Average value of absorbance of the highest concentration standard solution; Number of measurements
Percent variation coefficient of absorbance of zero concentration solution; -absorbance of zero concentration solution;
Average value of absorbance of zero concentration solution.
Working condition parameters
Calcium oxide
Additional instructions:
GB 8762.2 ---88
Appendix B
Working condition parameters of GGX-2 atomic absorption spectrophotometer (reference part)bzxz.net
Spectral passband
Burners
Lamp current
Solution lifting volume
mL/min
This standard was drafted by Beijing General Research Institute of Nonferrous Metals and Shanghai Yuelong Chemical Plant. This standard was drafted by Beijing Nonferrous Metals Research Institute and Shanghai Yuelong Chemical Plant. The main drafters of this standard are Zhen Rongqiao and Qiu Lifeng. Nitrogen oxide
Acetylene flow
Adjust to Hongyu
Male flame height
is about 15mm
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