GB/T 4103.11-2000 Chemical analysis methods for lead and lead alloys - Determination of zinc content

This standard specifies the determination method of zinc content in lead and lead alloys. This standard is applicable to the determination of zinc content in lead and lead alloys. Determination range: 0.00030% to 0.050%. GB/T 4103.11-2000 Chemical analysis method for lead and lead alloys Determination of zinc content GB/T4103.11-2000 Standard download decompression password: www.bzxz.net

GB/T4103.11.-2000
This standard is a revision of GB/T4103.12---1983 "Chemical analysis method for lead-based alloys - Determination of silver, zinc, magnesium and sodium by atomic absorption spectrophotometry"\"Determination of zinc content" method part, GB/T472.7--1984 "Chemical analysis method for lead ingots - Determination of zinc content by original factory absorption spectrophotometry". After the revision, the determination range of zinc is adjusted from 0.00030%~0.030% to 0.00030%~0.050%. This standard complies with:
GB/T1.11993 Guidelines for standardization work Unit 1: Rules for drafting and expressing standards Part 1: Basic provisions for standard preparation
GB/T1.4--1988 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB/T1467---1978 General provisions for chemical analysis method standards for metallurgical products Rules and general provisions GB/T7728:1987 General rules for flame atomic absorption spectrometry for chemical analysis of metallurgical products GB/T17433-1998 Basic terminology for chemical analysis of metallurgical products Appendix A of this standard is a reminder appendix.
This standard partially replaces GB/T4103.12-1983 and GB/T472.7--1984 from the date of entry into force. This standard is proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of the China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard was drafted by Shenyang Smelter and Northwest Copper Processing Plant of Baiyin Nonferrous Metals Company. This standard was drafted by Shenyang Smelter,
The main drafters of this standard are: Lu Hua and Liu Hui. 148
1 Scope
National Standard of the People's Republic of China
Chemical analysis methods for lead and lead alloys
Determination of zinc content
Methods This standard specifies the determination method of zinc content in lead and lead alloys. GB/T 4103. 11 : 2000
Partially replaces GB/T4103.121383
Replaces GB/T 479.7-1984
This standard is applicable to the determination of zinc content in lead and lead alloys. Determination range: 0.00030%~0.050%. 2 Method summary
The sample is decomposed with nitric acid (when Zn is 0.0010%, lead is precipitated and separated into lead sulfate). In nitric acid medium, use air acetylene flame to measure the absorbance of zinc at a wavelength of 213.8nm on an atomic absorption spectrometer. 3 Reagents
3.1 Tartaric acid.
3.2 Citric acid.
3 .3 Sulfuric acid (11), high-grade pure,
3.4 ​​Nitric acid (1+2), high-grade pure.
3.5 Nitric acid (1+3), high-grade pure.
3.6 Zinc standard stock solution: Weigh 0.1000g of metallic zinc (99.99%), place in a 250ml beaker, add 20ml of nitric acid (3.5), heat at low temperature to dissolve, drive off nitrogen oxides, remove, rinse the surface blood and the wall of the beaker with water. Cool to room temperature, transfer to a 1000ml volumetric flask, dilute with water to the mark, and mix. This solution contains 100μg zinc in 1ml. 3.7 Zinc standard solution: Transfer 50.00mL of zinc standard stock solution, place in a 1000mL volumetric flask, add 10mL of nitric acid (3.5). Dilute with water to the mark, and mix. This solution contains 5g zinc in 1ml. 4 Instruments
Atomic absorption spectrometer, with zinc 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 measurement solution, the characteristic concentration of zinc should not be greater than 0.30μg/ml. Precision: When the absorbance is measured 10 times with the highest concentration standard solution, the standard deviation should not exceed 1.50% of the average absorbance: When the absorbance is measured 10 times with the lowest concentration standard solution (not the "zero" standard solution), the standard deviation should not exceed 0.70% of the average absorbance of the highest standard solution.
Linearity of working curve: Divide the working curve into equal parts according to concentration. 5. The ratio of the absorbance difference of the highest segment to the absorbance difference of the lowest segment should not be less than 0.80.
Instrument working conditions are shown in Appendix A (Suggested Appendix) Approved by the State Administration of Quality and Technical Supervision on August 28, 2000 and implemented on December 1, 2000www.bzxz.net
5 Analysis steps
5.1 Test materials
Weigh the sample according to Table 1, accurate to 0.0001g: Zinc content %
0.00030~0.0010
> 0. 001 0-~ 0. 002 0
≥0. 002 0~0. 005 0
0. 005 0~0. 010
0. 010~0. 020
0.020~0.050
Carry out 2 independent determinations and take the average value. 5.2 Blank test
Carry out a blank test together with the sample.
5.3 Determination
5.3.1 Sample with Zn≤0.0010%
GB/T 4103.11-2000
Sample
Total volume of test solution, ml
5.3.1.1 Place the sample (5.1) in a 300ml beaker, add 60ml nitric acid (3.5), heat to dissolve at low temperature, and concentrate to a volume of about 30 mL.
5.3.1.2 Add 15ml sulfuric acid while stirring, cool, transfer the precipitate and solution into a 100mL volumetric flask, dilute to the mark with water, and mix well.
5.3.1.3 Take 25ml of the supernatant (5.3.1.2) and place it in a 100mL beaker, heat and evaporate to dryness, remove and cool, add 10ml of nitric acid (3.5), heat to boiling, cool, transfer to a 50mL volumetric flask, dilute to scale, and mix. The following is carried out according to 5.3.3. 5.3.2 Samples with Zn>0.0010%
5.3.2.1 Place the sample (5.1) in a 200mL beaker, add 15ml of nitric acid (3.4), 4g of tartaric acid (lead, tin, gold and citric acid), heat at low temperature to dissolve completely, and cool. 5.3.2.2 Transfer the solution (5.3.2.1) into a volumetric flask according to Table 1, dilute to the mark with water, mix, and 5.3.3 Measurement
Measure the absorbance of the above solution (5.3.1.3 or 5.3.2.2) at a wavelength of 213.8nm on an atomic absorption spectrometer using an air-acetylene flame and zeroing with water. Subtract the absorbance of the blank solution accompanying the sample from the measured absorbance, and find the corresponding zinc concentration from the working curve. 5.4 Drawing of the working curve.
5.4.1 Transfer 0, 2.00, 4.00, 6.00, 8.00, 10.00ml of zinc standard solution into a 50ml volumetric flask, add 10ml of nitric acid (3.5) and dilute to the mark with water, mix.
5.4.2 Measure the absorbance of the standard solution under the same conditions as the sample determination. The working curve is drawn with zinc concentration as the horizontal axis and absorbance (minus the absorbance of the "zero\standard solution") as the vertical axis. 6 Expression of analysis results
When Zn≤0.0010% or Zn0.0010%, calculate the percentage of zinc according to formula (1) and formula (2) respectively. Zn(%) = K:c:V, -V, × 10
Zn(%) C.Vo × 10-6
× 100
Where: K
Correction coefficient of lead sulfate precipitation to solution volume in 100mL volumetric flask (0.976 when the sample amount is 10.000 () g, oPbS(O), =-6. 2 g/mL);
GB/T 4103. 11--2000
Zinc concentration obtained from the working curve, ug/mL; V. —Total volume of test solution, mL.
V, volume of test solution taken, mL;
V2——Dilution volume after test solution is taken, mL; m. Mass of test material, g.
The result is expressed to three decimal places. If the zinc content is less than 0.010%, it is expressed to four decimal places; if it is less than 0.0010%, it is expressed to five decimal places.
7 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Zinc content
0. 000 30~ 0. 000 60
>0. 000 60～~ 0. 001 5
≥0. 001 5 ~0.003 0
>0.003 0-~0.005 0
0. 005 0~0. 010
>0. 010~~0. 030
>0.030~~0.050
Allowance
GB/T 4103. 11--2000
Appendix A
(Suggestive Appendix)
Instrument Working Conditions
The working conditions for determining zinc content using WYX-402 atomic absorption spectrometer are shown in Table A1: Table A1
Lamp current
Spectral passband
Burner height
Air flow
Art flow
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