This standard specifies the determination method of lead oxide content in direct zinc oxide. This standard is applicable to the determination of lead oxide content in direct zinc oxide. Determination range: 0.01～1.0%. GB/T 4372.2-2001 Chemical analysis method of direct zinc oxide Determination of lead oxide content by atomic absorption spectrometry GB/T4372.2-2001 Standard download decompression password: www.bzxz.net

GB/T 4372. 2—2001
This standard is a revision of GB/T4372.2—1984 "Zinc Oxide (Direct Method) Chemical Analysis Method Phosphoric Acid Solution Polarographic Determination of Lead Oxide and Oxidation Amount". The main content of the revision is the determination of lead oxide by atomic absorption spectrometry. This standard complies with:
GB/T1467—1978
General Principles and General Provisions of Standards for Chemical Analysis Methods of Metallurgical Products GB/T 7728--1987
General Principles of Flame Atomic Absorption Spectrometry for Chemical Analysis of Metallurgical Products GB/T17433—1998 Basic Terminology for Chemical Analysis of Metallurgical Products This standard will replace GB/T4372.2--1984 from the date of implementation. Appendix A of this standard is a reminder appendix. This standard is proposed by China Nonferrous Metals Industry Association. This standard is under the jurisdiction of China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard is drafted by Shuikoushan Mining Bureau. The main drafters of this standard are Kuang Haiyan, Yao Xiaohong, Mao Yanling and Ping Sheng. The National Technical Committee for Standardization of Nonferrous Metals is entrusted with the responsibility for the interpretation of this standard. 115
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of zinc oxide produced by direct process
Determination of lead oxide by atomic absorption spectrometry
Methods for chemical analysis of zincoxide produced by direct process-Determination of lead oxide content-Atomic absorption spectrometry method This standard specifies the method for the determination of lead oxide content in zinc oxide produced by direct process GB/T 4372.2--2001
Replaces GB/T4372.2-1984
This standard is applicable to the determination of lead oxide content in zinc oxide produced by direct process. Determination range: 0.01%~~1.0%. 2 Method Summary
The sample is dissolved in nitric acid. In a dilute nitric acid (5+95) medium, an air-acetylene flame is used to measure the absorbance of lead at a wavelength of 283.3nm on an atomic absorption spectrometer. The content of lead oxide is calculated using the standard curve method. 3 Reagents
3.1 Nitric acid (1+1).
3.2 Lead standard solution: Weigh 0.1000g of high-purity lead in a 300mL beaker, add 10mL of nitric acid (3.1), dissolve with slight heat, remove and cool, transfer to a 1000mL volumetric flask, wash the beaker with water and combine it in the volumetric flask, dilute with water to the mark, and mix. This solution contains 100 μg of lead in 1mL.
4 Instrument
Atomic absorption spectrometer, with a lead hollow cathode lamp. Under the best working conditions of the instrument, any instrument that can meet the following indicators can be used. Sensitivity: In a solution consistent with the matrix of the sample solution, the characteristic concentration of lead should not exceed 0.3μg/mL. Precision: When the absorbance is measured 10 times with the standard solution of the highest concentration, its standard deviation should not exceed 1.0% of the average absorbance; when the absorbance is measured 10 times with the standard solution of the lowest concentration (not the zero standard solution), its standard deviation should not exceed 0.5% of the average absorbance of the standard solution of the highest concentration.
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 not be less than 0.7.
See Appendix A (Suggested Appendix) for instrument working conditions. 5 Analysis steps
5.1 Test material
Weigh the sample according to Table 1 to an accuracy of 0.0001g. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China on July 10, 2001116
Implementation on December 1, 2001
Mass fraction of lead oxide, %
0. 01~0. 05
>0. 05～0.10
>0.10-~0.50
>0. 50~1. 00
5.2 Blank test
Perform a blank test together with the test sample.
GB/T 4372. 2-—2001
Test volume
Take the test solution volume, mL
5.3 Determination
5.3.1 Place the test sample (5.1) in a 150mL beaker, add 5mL nitric acid (3.1), cover with a watch glass, place on a hot plate and dissolve with slight heat. After complete dissolution, remove and cool, rinse the watch glass and the wall of the beaker with water, transfer to a 50mL volumetric flask, dilute to the mark with water, and mix. 5.3.2 Take the test solution according to Table 1 and transfer it to a 50mL volumetric flask, add 5mL nitric acid (3.1), dilute to the mark with water, and mix. 5.3.3 Use air-acetylene flame at a wavelength of 283.3nm on an atomic absorption spectrometer, adjust to zero with water, and measure the absorbance of the solution. Subtract the absorbance of the blank test solution from the measured absorbance, and find the corresponding lead concentration from the working curve. 5.4 Drawing of working curve
5.4.1 Take 0, 1.00, 2.00, 3.00, 4.00, 5.00mL of lead standard solution (3.2) and place them in a set of 100mL volumetric flasks respectively, add 10mL of nitric acid (3.1), dilute to the scale with water, and mix. 5.4.2 Under the same conditions as the test sample solution, measure the absorbance of the series of standard solutions. Draw the working curve with the lead concentration as the horizontal axis and the absorbance (minus the absorbance of the zero concentration solution) as the vertical axis. 6
Description of analysis results
Calculate the mass fraction of lead oxide according to formula (1): w(bo) -c:V.X10×1. 0772 × 100m.V
Wherein: w(PbO)-
Mass fraction of lead oxide, %;
-Lead concentration found from the working curve, pg/mL; V. ---Total volume of sample solution, mL, V,-Volume of aliquoted test solution, mL;
V,-Volume of aliquoted test solution after dilution, mL,-Mass of sample,;
1. 077 2--
7Allowable difference
Coefficient for converting lead into lead oxide.
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Mass fraction of lead oxide
0. 010~0. 050
>0. 050~0.100
>0. 100～0.500
>0. 500～1. 000
Tolerance
(1)
GB/T4372.2—2001
Appendix A
(Suggestive appendix)
Instrument working conditions
The reference working conditions of GGX-5 atomic absorption spectrometer are shown in Table A1: Table A1
Wavelength, nmwww.bzxz.net
Lamp current, mA
Color filter passband, nm
Air flow, L/min
Acetylene flow, L/min
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