GB/T 3884.9-2000 Chemical analysis methods for copper concentrates - Determination of arsenic and bismuth content
Some standard content:
GB/T3884.9--2000
Method 1 of this standard is a newly added analytical method; Method 2 and Appendix A are reconfirmations of the original GB/T3884.10--1983 "Chemical analysis method for copper concentrate - Determination of arsenic content by potassium bromate volumetric method" and GB/T3884.10-1983 "Chemical analysis method for copper concentrate - Determination of arsenic content by potassium diethyldithioamide silver spectrophotometric method", with only editorial changes made. This standard complies with:
GB/T1.1-1993 Standardization Work Guidelines Unit 1: Rules for Drafting and Presenting Standards Part 1: Basic Regulations for Standardization
GB/T1.4-1988 Standardization Work Guidelines for Chemical Analysis Methods GB/T1467-1978 General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products GB/T7729-1987 General Principles for Spectrophotometric Methods for Chemical Analysis of Metallurgical Products GB/T17433-1998 Basic Terminology for Chemical Analysis of Metallurgical Products This standard shall replace GB/T3884.9-1983 and GB/T3884.10-1983 from the date of implementation. Appendix A in this standard is the standard appendix, and Appendix B is the indicative appendix. This standard was proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of the China Nonferrous Metals Industry Standards and Quality Research Institute. This standard was drafted by Dazhi Nonferrous Metals Company. The main drafters of this standard are: Hu Junkai, Liu Zhendong, Li Xiaoyu; Method 2: Chen Shizhong, Li Yuqin, Yan Li; Appendix A: Dong Yuanmei, Li Xiaoyu, Li Bixiong.
1 Scope
National Standard of the People's Republic of China
Chemical analysis methods of copper concentrates
Determination of arsenic and bismuth contents
Methodsfor chemical analysis of copper concentratesDeterminationofarsenicandbismuthcontentsMethod 1 Determination of arsenic and bismuth by hydride generation-atomic fluorescence spectrometry This standard specifies the method for the determination of arsenic and bismuth contents in copper concentrates. GB/T3884.9—2000
Replaces GB/T3884.9-1983
GB/T3884.10—1983
This standard applies to the determination of arsenic and bismuth contents in copper concentrates. Determination range: arsenic 0.010%~0.10%; bismuth 0.010%~0.50%. 2 Method Summary
The sample is dissolved in nitric acid and sulfuric acid. In an ammonia solution, arsenic and bismuth are separated from impurities such as copper using iron as a carrier. Ascorbic acid is used for pre-reduction, and the remaining copper is masked with sulfur glands. In the hydride generator, arsenic and bismuth are reduced to hydrides by potassium borohydride, and fluorine gas is introduced into the quartz furnace atomizer, and its fluorescence intensity is measured on an atomic fluorescence spectrometer. 3 Reagents
3.1 Potassium chloride.
3.2 Nitric acid (pl.42g/mL).
3.3 Hydrochloric acid (pl.19 g/mL).
3.4 Ammonia water (p0.90g/mL).
3.5 Hydrochloric acid (1+24).
3.6 Mixed acid: Mix three unit volumes of hydrochloric acid (3.3) with one unit volume of nitric acid (3.2) and cool. 3.7
Sulfuric acid (1+1).
3.8 Ammonia water (2+98).
3.9 Ammonium ferric sulfate solution: Weigh 84.4g ammonium ferric sulfate [FeNH, (SO,): · 12H, O] and dissolve it in 500mL water, add 20mL sulfuric acid (3.7), dilute with water to 1L, mix well, this solution contains 10mg iron in 1mL. 3.10 Sulfur-ascorbic acid mixed solution: Weigh 5g of sulfur and ascorbic acid respectively, dissolve in water, dilute to 100mL, mix well. 3.11 Potassium borohydride solution (7g/L): Weigh 7g of potassium borohydride and dissolve in 1000mL of sodium hydroxide solution (2g/L), prepare it on the spot. This solution is used to measure bismuth.
3.12 Potassium borohydride solution (10g/L): Weigh 10g potassium borohydride and dissolve it in 1000mL potassium hydroxide solution (2g/L). Prepare and use it now. This solution is used to measure arsenic.
3.13 Arsenic standard storage solution: Weigh 0.1320g arsenic trioxide (pre-dried at 100-105℃ for 1h, placed in a desiccator and cooled to room temperature) in a 100mL beaker, add 5mL sodium hydroxide solution (200g/L), heat at low temperature to dissolve it, add 50mL water, 2 drops of phenolic ethanol solution (1g/L), neutralize with sulfuric acid until the red color just disappears, then add 2mL in excess, transfer to a 1L volumetric flask, dilute with water to the scale, mix well, this National Quality and Technical Supervision Bureau approved on February 16, 200046
2000-08-01 implementation
1mL of solution contains 100μg arsenic.
GB/T 3884.9-2000
3.14 Arsenic standard solution: Pipette 20.00mL of standard stock solution of arsenic into a 500mL volumetric flask, dilute to the mark with water, mix, this solution contains 4μg of arsenic in 1mL.
3.15 Bismuth standard stock solution: Weigh 0.1000g of bismuth (99.99%) into a 250mL beaker, add 50mL of nitric acid (1+1), cover with a watch glass, heat until completely dissolved, slightly boil to drive off nitrogen oxides, cool, transfer to a 1L volumetric flask with nitric acid (1+24), dilute to the mark, mix, this solution contains 100μg of bismuth in 1mL.
3.16 Bismuth standard solution: Pipette 20.00mL of bismuth standard storage solution into a 500mL volumetric flask, add 100mL of hydrochloric acid (3.3), dilute to the mark with water, mix well, and 1mL of this solution contains 4μg bismuth. 4 Instruments
Atomic fluorescence spectrometer, with shielded quartz furnace atomizer, glass hydride generator and arsenic and bismuth special hollow cathode lamp or high-intensity hollow cathode lamp. Fluorine gas: used as shielding gas and carrier gas. Under the best working conditions of the instrument, any instrument that can meet the following indicators can be used. Detection limit: not more than 9×10-1°g/mL. Precision: The fluorescence intensity is measured 10 times with 0.1μg/mL arsenic and bismuth standard solutions, and the standard deviation does not exceed 5.0% of the average fluorescence intensity.
For instrument working conditions, see Appendix B (Suggested Appendix). 5 Samples
5.1 The sample particle size should be not less than 0.082mm. 5.2 After drying the sample at 100105℃ for 1h, place it in a desiccator and cool it to room temperature. 6 Analysis steps
6.1 Test material
Weigh 0.20g of test material to the nearest 0.0001g. Perform two independent determinations and take the average value. 6.2 Blank test
Perform a blank test with the test material.
6.3 Determination
6.3.1 Place the test material (6.1) in a 300mL beaker, moisten it with a little water, add about 0.1g of potassium chlorate to mix with the test material, add 10mL of nitric acid, cover with Table III, place it on a low-temperature electric heating plate and heat to dissolve, repeatedly add a small amount of potassium chlorate until no monomer sulfur is precipitated, continue to dissolve to a small volume, cool slightly, add 5mL of sulfuric acid, and mix well. When thick smoke is emitted during heating, remove it and cool it down, blow the table and the wall of the cup with water to about 50mL, and heat to boil. 6.3.2 Add water to about 150mL, add 10mL ammonium ferric sulfate, heat to nearly boiling, remove, and add nitrogen water (3.4) while stirring to neutralize until the generated copper hydroxide dissolves (dissolved in dark blue), then add 25mL in excess, heat to boil, and keep warm for 1h, filter with medium-speed filter paper, wash the beaker 3 times and the precipitate 4~5 times with hot ammonia water (3.8), transfer the precipitate to the original beaker with 30mL hydrochloric acid (3.3), and then wash the filter paper with hydrochloric acid (3.5) until it is yellow without trivalent iron. Evaporate at low temperature to about 70mL, remove and cool, transfer to a 100mL volumetric flask, dilute to scale with water, and mix well.
6.3.3 Take 10mL of the above solution (6.3.2) in a 100mL volumetric flask, add 60mL water, 10mL mixed acid, and 10mL thiourea-ascorbic acid mixed solution, and dilute to scale with water. This solution is used for measuring monuments. 6.3.4 Take the solution (6.3.2) according to Table 1 and place it in a 100mL volumetric flask containing 60mL water and 10mL hydrochloric acid (3.3), add 10mL thiourea-ascorbic acid mixed solution, and dilute to the mark with water. This solution is used to measure bismuth. 47
Bismuth content, %
0.010~0.10
>0.10~0.15
>0.15~0.50
GB/T3884.9--2000
Volume of the solution, mL
6.3.5 Pipette 2.00mL of the test solution (6.3.3 or 6.3.4) into the hydride generator and measure the fluorescence intensity of arsenic and bismuth respectively according to the instrument operating procedures. Subtract the fluorescence intensity of the blank solution accompanying the sample and find the corresponding concentrations of bismuth and stele from the working curve. 6.4 Drawing of working curves for monument and bismuth.
6.4.1 Drawing of working curves: Pipette 0, 0.50, 1.00, 2.00, 4.00, 8.00 mL of arsenic standard solution into a set of 100 mL volumetric flasks, add 60 mL of water, 10 mL of mixed acid, 10 mL of thiourea-ascorbic acid mixed solution, and dilute to scale with water. Pipette 2.00 mL of this solution into the hydride generator, measure its fluorescence intensity according to the instrument operation procedure, subtract the fluorescence intensity of the "zero" standard solution, and draw the working curve with arsenic concentration as the horizontal axis and fluorescence intensity as the vertical axis. 6.4.2 Drawing of bismuth working curve: Pipette 0.50, 1.00, 4.00, 8.00 mL of the standard solution of bismuth into a set of 100 mL volumetric flasks containing 600 mL of water and 10 mL of hydrochloric acid (3.3), add 10 mL of sulfur-ascorbic acid mixed solution, dilute to scale with water, draw 2.00 mL of this solution into the hydride generator, measure its fluorescence intensity according to the instrument operation procedure, subtract the fluorescence intensity of the "zero" standard solution, and draw the working curve with bismuth concentration as the horizontal axis and fluorescence intensity as the vertical axis. 7 Expression of analysis results
Calculate the percentage of bismuth or bismuth according to formula (1): cV. .V×10-s
As or Bi(%)=9
Where: -arsenic or bismuth concentration obtained from the working curve, μg/mL, Va
total volume of test solution, mL;
V—volume of aliquoted test solution, mL
Vz—volume of aliquoted test solution after dilution, mLmo—mass of test material, g.
The result is expressed to two decimal places. If the content is less than 0.10%, it is expressed to three decimal places. 8 Allowable difference
The difference between the analysis results of laboratories shall not be greater than the allowable difference listed in Table 2. Table 2
Element content
0.0100.030
Arsenic, bismuth
>0.030~0.060
>0.060~0.10
>0.10~0.20
>0.20~0.50
....(1)
Tolerance
9Range
GB/T3884.9—2000
Method 2 Determination of arsenic content by potassium titration
This standard specifies the method for determining the content of arsenic in copper concentrate. This standard is applicable to the determination of arsenic content in copper concentrate. Determination range:>0.10%~2.00%. 10 Summary of the method
The sample is decomposed with acid. In a 6 mol/L acid medium, potassium bromide is used as a catalyst, and ammonium sulfate is used to reduce pentavalent arsenic to trivalent arsenic. Arsenic trinitride is separated from other elements by distillation. After arsenic trifluoride is absorbed by water, methyl orange is used as an indicator, and potassium bromide standard titration solution is used to titrate until the red color disappears.
11 Reagents
11.1 Potassium bromide.
11.2 Ammonium sulfate.
11.3 Potassium fluoride.
11.4 Hydrochloric acid (pl1.19 mol/L).
11.5 Nitric acid (p1.42 mol/L).
11.6 Sulfuric acid (1+1).
11.7 Methyl orange indicator (1 g/L).
11.8 Arsenic standard solution: Weigh 0.2641g of standard arsenic trioxide (pre-dried at 100-105℃ for 1h, placed in a desiccator and cooled to room temperature), place in a 250mL beaker, add 10mL of sodium hydroxide solution (200g/L), heat at low temperature until completely dissolved, add 50mL of water, 2 drops of phenol ethanol solution (1g/L), neutralize with hydrochloric acid (1+1) until the red color just fades and add 2 drops, transfer to a 1L volumetric flask, dilute to the scale with water, mix well, 1mL of this solution contains 0.0002g of arsenic. 11.9 Potassium bromate standard titration solution [c(1/6KBrO,）=0.005mol/L] 11.9.1 Preparation
Weigh 0.74g potassium bromate and 3.7g potassium bromide into a 250mL beaker, add a small amount of water, heat to dissolve, cool slightly, transfer to a reagent bottle, dilute to 5L with water, and mix well.
11.9.2 Calibration
Pipette three portions of 20.00mL of arsenic standard solution, place them in 250mL beakers, dilute to 100mL with water, add 15mL of hydrochloric acid, heat to 40~60℃, add 2 drops of methyl orange indicator, and titrate with potassium bromate titration solution until the red color of the solution disappears as the end point. Perform a blank test along with the calibration.
Calculate the actual concentration of potassium bromate standard titration solution according to formula (2): G.
c=(V,-V)×0. 03746
Actual concentration of potassium bromate standard titration solution, mol/L, where.
Mass concentration of arsenic standard solution, g/mL, G
V. Volume of potassium bromate standard titration solution consumed in titrating arsenic standard solution during calibration, mL; V. Volume of potassium bromate standard titration solution consumed in titrating blank test solution during calibration, mL, V.
Mass of arsenic equivalent to 1.00mL potassium bromate standard titration solution [c(1/6KBrO,)=1.00mol/L], g/mol. Perform three calibrations in parallel. If the range is not greater than 1×10-5mol/L, take the average value. Otherwise, recalibrate. 49
12 Apparatus
Distillation apparatus, as shown in Figure 1.
GB/T3884.9—2000
1—Electric furnace (with pressure regulator); 2—Distillation flask (250mL), 3—Mercury thermometer, 4—Glass tube, 5—Cooling device (spherical) 6—Absorption cup (250mL) Figure 1 Schematic diagram of distillation apparatus
13 Sample
13.1 The sample particle size should not be greater than 0.082mm. 13.2 The sample should be dried at 100-105℃ for 1h and then placed in a desiccator to cool to room temperature. 14 Analysis steps
14.1 Sample
Weigh the sample according to Table 3, accurate to 0.0001g. Table 3
Monument contains whole, %
>1.00~2.00
Independently carry out two determinations and take the average value. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
Sample plate g
14.3.1 Place the sample (14.1) in a 250mL beaker, add 10~15mL nitric acid, add 0.3~0.5g potassium chlorate in batches, heat on a hot plate until the sample is completely dissolved, remove, cool slightly, wash the wall with water, add 5mL sulfuric acid, heat until thick smoke appears, remove, and cool slightly. 14.3.2 Use a small amount of water to blow the cup wall, heat until the soluble salt is dissolved, transfer to a 250mL conical flask pre-filled with 0.3g potassium bromate and 0.3g hydrazine sulfate, add 40mL hydrochloric acid, wash the beaker with water, and make the total volume of the solution in the conical flask 80mL. 14.3.3, connect the steaming device according to Figure 1, and heat the steamed stuffing at 100105℃. The distillate is absorbed in a 150mL beaker pre-filled with 50mL water. When the volume of the residual liquid is about 1/3 of the original volume, remove the conical flask, blow the inner wall and the mouth of the condenser with water, and add 50
of the washing liquid into the absorption cup.
GB/T3884.9--2000
14.3.4 Heat the absorption liquid to 40~60℃, add 2 drops of methyl orange indicator, and titrate with potassium bromide standard titration solution until the red color disappears.
15 Expression of analysis results
Calculate the percentage of arsenic according to formula (3):
As(%) =cV-V) × 0. 037 46, m
Wherein: c actual concentration of potassium bromate standard titration solution, mol/L, x100
V——the volume of potassium bromate standard titration solution consumed when titrating the sample solution during the determination, mL, V:-the volume of potassium bromate standard titration solution consumed when titrating the blank test solution during the determination, mL;-the mass of the sample, g;
0.03746——the mass of arsenic equivalent to 1.00 potassium bromate standard titration solution [c (1/6KBrO,) = 1.00mol/L]? g/mol. The obtained results are expressed to two decimal places.
16 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 4. Table 4
>0.10~0.30
>0.30~0.60
>0.60~1.00
>1.00~2.00
(3)
A1 range
GB/T3884.9-2000
Appendix A
(Appendix to the standard)
Spectrophotometric determination of arsenic content by silver diethyldithiocarbamateThis standard specifies the method for determining the content of arsenic in copper concentrate. This standard is applicable to the determination of arsenic content in copper concentrate. Determination range: 0.010%~0.10%. A2Method summary
The sample is decomposed with nitric acid. Arsenic is reduced by zinc in a 1.2 mol/L sulfuric acid medium, and the generated arsenic hydrogen gas is absorbed by a copper reagent silver salt chloroform solution. Arsenic oxide reduces the silver in the copper reagent silver salt, and the precipitated silver is in a single colloidal state and appears red. The absorbance is measured at 530 nm on a spectrophotometer, and the content of arsenic is calculated according to the standard curve method. A3Reagents
A3.1 Arsenic-free zinc particles.
A3.2 Potassium chloride.
A3.3 Nitric acid (pl.42 g/mL).
A3.4 Sulfuric acid (1+1). wwW.bzxz.Net
A3.5 Ammonium ferric sulfate solution (20g/L).
A3.6 Copper sulfate solution (20g/L).
A3.7 Potassium iodide bath solution (300g/L).
A3.8 Fluorothiocyanate solution (200g/L), weigh 20g of stannous chloride (SnCl·2H20) in a 250mL beaker, add 30mL of hydrochloric acid (1+1), heat to dissolve, cool, and dilute with water to 100mL. A3.9 Tartaric acid solution (500g/L).
A3.10 Trifluoromethane.
A3.11 Lead acetate absorbent cotton: Soak the absorbent cotton in a lead acetate (100g/L) solution containing acetic acid (0.5%), take it out after it is submerged, dry it in air and set aside.
A3.12 Silver diethyldithiocarbamate (hereinafter referred to as copper reagent silver salt) chloroform solution (5g/L): Weigh 2.5g of copper reagent silver salt into a 500mL reagent bottle, add 500mL of triethanolamine (4%) in trichloromethane solution, and shake to dissolve it. Let it stand overnight. Filter and store in a brown reagent bottle. The shelf life should not exceed one week. A3.13 Arsenic standard storage solution: Weigh 0.1320g of arsenic trichloride (pre-dried at 100~105℃ for 1h, placed in a desiccator and cooled to room temperature) into a 100mL beaker, add 5mL of sodium hydroxide solution (200mg/L), heat at low temperature to dissolve it, add 50mL of water, 2 drops of phenolic acid ethanol solution (1g/L), neutralize with sulfuric acid until the red color just disappears, then filter 2mL, transfer to a 1L volumetric flask, dilute to the scale with water, mix well, this solution contains 100μg of arsenic.
A3.14 Standard solution: Pipette 20.00 mL of the standard storage solution into a 500 mL volumetric flask, dilute to the mark with water, and mix. This solution contains 4 μg of arsenic in 1 mL.
A4 Instruments
A4.1 Spectrophotometer.
A4.2 Arsenic hydrogen gas generation-absorption device, as shown in Figure A1. 52
GB/T3884.9—2000
110~120
1—100mL conical flask; 2-rubber stopper, 3-air guide tube (inner weight 5mm); 4-glass ball tube [ball diameter 10~12mm, filled with lead acetate absorbent cotton (A3.11) J; 5-rubber tube: 6-absorption tube (10mL stoppered colorimetric tube), 7-lower end of air guide tube (inner diameter 1mm) Figure A1 Arsenic hydrogen gas generation-absorption device diagram
A5 Sample
A5.1 The sample particle size should not be greater than 0.082mm. A5.2 The sample should be dried at 100~105℃ for 1h and then placed in a desiccator to cool to room temperature. A6 Analysis steps
A6.1 Sample
Weigh 0.20g of sample to the nearest 0.0001g. Conduct two independent determinations and take the average value. A6.2 Blank test
Carry out a blank test with the sample.
A6.3 Determination
A6.3.1 Dissolution of sample
A6.3.1.1 Place the sample (A6.1) in a 150mL beaker, add 0.1g potassium chlorate and mix well, add 10mL nitric acid and place on a hot plate to heat and decompose, repeatedly add a small amount of potassium nitrate to treat until no monomer sulfur is precipitated, continue to evaporate until nearly dry, cool slightly, add 5~8mL sulfuric acid along the wall of the cup and evaporate until thick smoke appears, remove and cool slightly. A6.3.1.2 Blow the cup with water, heat and boil to dissolve the soluble salt, cool to room temperature, transfer to a 100mL volumetric flask, dilute to the scale with water, and mix well.
A6.3.2 Absorption
A6.3.2.1 Take the test solution (A6.3.1.2) according to Table A1 and put it into a 100mL conical flask. Table A1
Content, %
>0.020~0.070
>0.070~0.10
Amount of test solution, mL
A6.3.2.2 Add 7mL sulfuric acid, dilute to 40mL with water, add 5mL potassium iodide solution, 2mL stannous chloride solution, and mix each reagent thoroughly. Let stand for 2~3min until the yellow color of the solution disappears. Add 5mL tartaric acid solution and let stand for 10min. A6.3.2.3 Transfer 10.00mL of copper reagent silver salt trifluoromethane solution to a 10mL absorption tube, add 5g of arsenic-free zinc particles to the conical flask, and immediately connect the arsenic hydrogen gas generation-absorption device according to Figure A1. A6.3.2.4 After 40 minutes of reaction, remove the airway tube, rinse the airway tube with a small amount of trichloromethane, combine the washing liquid in the absorption tube, and dilute to 10.00mL with trichloromethane, and mix well.
A6.3.3 Measurement
GB/T3884.9—2000
Transfer part of the solution (A6.3.2.4) to a dry 1cm absorption tube, use the copper reagent silver salt trichloromethane solution as a reference, and measure its absorbance at a wavelength of 530nm on a spectrophotometer. Find the corresponding arsenic on the working curve. A6.4 Drawing of the working curve.
Take 0, 2.00, 4.00, 6.00, 8.00, 10.00mL of arsenic standard solution, place them in a group of 100mL conical flasks, add 6mL of ammonium ferric sulfate solution and 6mL of copper sulfate solution, and mix well. Draw the working curve according to A6.3.2.2~absorbance as the ordinate. A7
Analysis result statement
Calculate the percentage content of arsenic according to formula (4):
As(%) =
Where: m2
(mz -- m,) . V. × 10--
The arsenic content of the test solution found on the working curve, g, the arsenic content of the blank solution of the sample found on the working curve, g: the total volume of the test solution, mL;
V,—the volume of the test solution taken, mL,
the mass of the sample, g.
The results are expressed to three decimal places.
Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table A2. Table A2
0.010~0.020
>0.020~0.040
>0.040~0.070
>0. 070~0.10
Appendix B
(Suggestive Appendix)
Instrument working conditions
The working conditions of the AFS-220 dual-channel atomic fluorescence spectrometer are as shown in Table B1: Determination
Lamp current
Negative high voltage
Carrier gas flow plate
Shielding gas flow
Atomization temperature
16.3.3 is carried out. With arsenic content as the horizontal axis, X100
addition time
delay time
sampling time9 Tartaric acid solution (500g/L).
A3.10 Trifluoromethane.
A3.11 Lead acetate absorbent cotton: Soak the absorbent cotton in lead acetate (100g/L) solution containing acetic acid (0.5%), take it out after it is soaked, dry it in the air and set it aside.
A3.12 Silver diethyldithiocarbamate (hereinafter referred to as copper reagent silver salt) chloroform solution (5g/L): Weigh 2.5g of copper reagent silver salt into a 500mL reagent bottle, add 500mL triethanolamine (4%) trichloromethane solution, shake it to dissolve. Let it stand overnight. Filter and store in a brown reagent bottle. The usage period should not exceed one week. A3.13 Arsenic standard stock solution: weigh 0.1320g arsenic trichloride (pre-dried at 100~105℃ for 1h, placed in a desiccator and cooled to room temperature) in a 100mL beaker, add 5mL sodium hydroxide solution (200mg/L), heat at low temperature to dissolve it, add 50mL water, 2 drops of phenolic acid ethanol solution (1g/L), neutralize with sulfuric acid until the red color just disappears, then filter 2mL, transfer to a 1L volumetric flask, dilute with water to the scale, mix well, this solution contains 100μg arsenic.
A3.14 Standard solution: transfer 20.00mL of the standard stock solution to a 500mL volumetric flask, dilute with water to the scale, mix well. This solution contains 4μg arsenic in 1mL.
A4 Instruments
A4.1 Spectrophotometer.
A4.2 Arsenic hydrogen gas generation-absorption device, as shown in Figure A1. 52
GB/T3884.9—2000
110~120
1—100mL conical flask; 2-rubber stopper, 3-air guide tube (inner weight 5mm); 4-glass ball tube [ball diameter 10~12mm, filled with lead acetate absorbent cotton (A3.11) J; 5-rubber tube: 6-absorption tube (10mL stoppered colorimetric tube), 7-lower end of air guide tube (inner diameter 1mm) Figure A1 Arsenic hydrogen gas generation-absorption device diagram
A5 Sample
A5.1 The sample particle size should not be greater than 0.082mm. A5.2 The sample should be dried at 100~105℃ for 1h and then placed in a desiccator to cool to room temperature. A6 Analysis steps
A6.1 Sample
Weigh 0.20g of sample to the nearest 0.0001g. Conduct two independent determinations and take the average value. A6.2 Blank test
Carry out a blank test with the sample.
A6.3 Determination
A6.3.1 Dissolution of sample
A6.3.1.1 Place the sample (A6.1) in a 150mL beaker, add 0.1g potassium chlorate and mix well, add 10mL nitric acid and place on a hot plate to heat and decompose, repeatedly add a small amount of potassium nitrate to treat until no monomer sulfur is precipitated, continue to evaporate until nearly dry, cool slightly, add 5~8mL sulfuric acid along the wall of the cup and evaporate until thick smoke appears, remove and cool slightly. A6.3.1.2 Blow the cup with water, heat and boil to dissolve the soluble salt, cool to room temperature, transfer to a 100mL volumetric flask, dilute to the scale with water, and mix well.
A6.3.2 Absorption
A6.3.2.1 Take the test solution (A6.3.1.2) according to Table A1 and put it into a 100mL conical flask. Table A1
Content, %
>0.020~0.070
>0.070~0.10
Amount of test solution, mL
A6.3.2.2 Add 7mL sulfuric acid, dilute to 40mL with water, add 5mL potassium iodide solution, 2mL stannous chloride solution, and mix each reagent thoroughly. Let stand for 2~3min until the yellow color of the solution disappears. Add 5mL tartaric acid solution and let stand for 10min. A6.3.2.3 Transfer 10.00mL of copper reagent silver salt trifluoromethane solution to a 10mL absorption tube, add 5g of arsenic-free zinc particles to the conical flask, and immediately connect the arsenic hydrogen gas generation-absorption device according to Figure A1. A6.3.2.4 After 40 minutes of reaction, remove the airway tube, rinse the airway tube with a small amount of trichloromethane, combine the washing liquid in the absorption tube, and dilute to 10.00mL with trichloromethane, and mix well.
A6.3.3 Measurement
GB/T3884.9—2000
Transfer part of the solution (A6.3.2.4) to a dry 1cm absorption tube, use the copper reagent silver salt trichloromethane solution as a reference, and measure its absorbance at a wavelength of 530nm on a spectrophotometer. Find the corresponding arsenic on the working curve. A6.4 Drawing of the working curve.
Take 0, 2.00, 4.00, 6.00, 8.00, 10.00mL of arsenic standard solution, place them in a group of 100mL conical flasks, add 6mL of ammonium ferric sulfate solution and 6mL of copper sulfate solution, and mix well. Draw the working curve according to A6.3.2.2~absorbance as the ordinate. A7
Analysis result statement
Calculate the percentage content of arsenic according to formula (4):
As(%) =
Where: m2
(mz -- m,) . V. × 10--
The arsenic content of the test solution found on the working curve, g, the arsenic content of the blank solution of the sample found on the working curve, g: the total volume of the test solution, mL;
V,—the volume of the test solution taken, mL,
the mass of the sample, g.
The results are expressed to three decimal places.
Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table A2. Table A2
0.010~0.020
>0.020~0.040
>0.040~0.070
>0. 070~0.10
Appendix B
(Suggestive Appendix)
Instrument working conditions
The working conditions of the AFS-220 dual-channel atomic fluorescence spectrometer are as shown in Table B1: Determination
Lamp current
Negative high voltage
Carrier gas flow plate
Shielding gas flow
Atomization temperature
16.3.3 is carried out. With arsenic content as the horizontal axis, X100
addition time
delay time
sampling time9 Tartaric acid solution (500g/L).
A3.10 Trifluoromethane.
A3.11 Lead acetate absorbent cotton: Soak the absorbent cotton in lead acetate (100g/L) solution containing acetic acid (0.5%), take it out after it is soaked, dry it in the air and set it aside.
A3.12 Silver diethyldithiocarbamate (hereinafter referred to as copper reagent silver salt) chloroform solution (5g/L): Weigh 2.5g of copper reagent silver salt into a 500mL reagent bottle, add 500mL triethanolamine (4%) trichloromethane solution, shake it to dissolve. Let it stand overnight. Filter and store in a brown reagent bottle. The usage period should not exceed one week. A3.13 Arsenic standard stock solution: weigh 0.1320g arsenic trichloride (pre-dried at 100~105℃ for 1h, placed in a desiccator and cooled to room temperature) in a 100mL beaker, add 5mL sodium hydroxide solution (200mg/L), heat at low temperature to dissolve it, add 50mL water, 2 drops of phenolic acid ethanol solution (1g/L), neutralize with sulfuric acid until the red color just disappears, then filter 2mL, transfer to a 1L volumetric flask, dilute with water to the scale, mix well, this solution contains 100μg arsenic.
A3.14 Standard solution: transfer 20.00mL of the standard stock solution to a 500mL volumetric flask, dilute with water to the scale, mix well. This solution contains 4μg arsenic in 1mL.
A4 Instruments
A4.1 Spectrophotometer.
A4.2 Arsenic hydrogen gas generation-absorption device, as shown in Figure A1. 52
GB/T3884.9—2000
110~120
1—100mL conical flask; 2-rubber stopper, 3-air guide tube (inner weight 5mm); 4-glass ball tube [ball diameter 10~12mm, filled with lead acetate absorbent cotton (A3.11) J; 5-rubber tube: 6-absorption tube (10mL stoppered colorimetric tube), 7-lower end of air guide tube (inner diameter 1mm) Figure A1 Arsenic hydrogen gas generation-absorption device diagram
A5 Sample
A5.1 The sample particle size should not be greater than 0.082mm. A5.2 The sample should be dried at 100~105℃ for 1h and then placed in a desiccator to cool to room temperature. A6 Analysis steps
A6.1 Sample
Weigh 0.20g of sample to the nearest 0.0001g. Conduct two independent determinations and take the average value. A6.2 Blank test
Carry out a blank test with the sample.
A6.3 Determination
A6.3.1 Dissolution of sample
A6.3.1.1 Place the sample (A6.1) in a 150mL beaker, add 0.1g potassium chlorate and mix well, add 10mL nitric acid and place on a hot plate to heat and decompose, repeatedly add a small amount of potassium nitrate to treat until no monomer sulfur is precipitated, continue to evaporate until nearly dry, cool slightly, add 5~8mL sulfuric acid along the wall of the cup and evaporate until thick smoke appears, remove and cool slightly. A6.3.1.2 Blow the cup with water, heat and boil to dissolve the soluble salt, cool to room temperature, transfer to a 100mL volumetric flask, dilute to the scale with water, and mix well.
A6.3.2 Absorption
A6.3.2.1 Take the test solution (A6.3.1.2) according to Table A1 and put it into a 100mL conical flask. Table A1
Content, %
>0.020~0.070
>0.070~0.10
Amount of test solution, mL
A6.3.2.2 Add 7mL sulfuric acid, dilute to 40mL with water, add 5mL potassium iodide solution, 2mL stannous chloride solution, and mix each reagent thoroughly. Let stand for 2~3min until the yellow color of the solution disappears. Add 5mL tartaric acid solution and let stand for 10min. A6.3.2.3 Transfer 10.00mL of copper reagent silver salt trifluoromethane solution to a 10mL absorption tube, add 5g of arsenic-free zinc particles to the conical flask, and immediately connect the arsenic hydrogen gas generation-absorption device according to Figure A1. A6.3.2.4 After 40 minutes of reaction, remove the airway tube, rinse the airway tube with a small amount of trichloromethane, combine the washing liquid in the absorption tube, and dilute to 10.00mL with trichloromethane, and mix well.
A6.3.3 Measurement
GB/T3884.9—2000
Transfer part of the solution (A6.3.2.4) to a dry 1cm absorption tube, use the copper reagent silver salt trichloromethane solution as a reference, and measure its absorbance at a wavelength of 530nm on a spectrophotometer. Find the corresponding arsenic on the working curve. A6.4 Drawing of the working curve.
Take 0, 2.00, 4.00, 6.00, 8.00, 10.00mL of arsenic standard solution, place them in a group of 100mL conical flasks, add 6mL of ammonium ferric sulfate solution and 6mL of copper sulfate solution, and mix well. Draw the working curve according to A6.3.2.2~absorbance as the ordinate. A7
Analysis result statement
Calculate the percentage content of arsenic according to formula (4):
As(%) =
Where: m2
(mz -- m,) . V. × 10--
The arsenic content of the test solution found on the working curve, g, the arsenic content of the blank solution of the sample found on the working curve, g: the total volume of the test solution, mL;
V,—the volume of the test solution taken, mL,
the mass of the sample, g.
The results are expressed to three decimal places.
Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table A2. Table A2
0.010~0.020
>0.020~0.040
>0.040~0.070
>0. 070~0.10
Appendix B
(Suggestive Appendix)
Instrument working conditions
The working conditions of the AFS-220 dual-channel atomic fluorescence spectrometer are as shown in Table B1: Determination
Lamp current
Negative high voltage
Carrier gas flow plate
Shielding gas flow
Atomization temperature
16.3.3 is carried out. With arsenic content as the horizontal axis, X100
addition time
delay time
sampling time1) Place in a 150mL beaker, add 0.1g potassium chlorate and the sample and mix well, add 10mL nitric acid and place on a hot plate to heat and decompose, repeatedly add small amounts of potassium nitrate until no monomeric sulfur is precipitated, continue to evaporate until nearly dry, cool slightly, add 5~8mL sulfuric acid along the wall of the cup and evaporate until thick smoke appears, remove and cool slightly. A6.3.1.2 Blow the cup with water, heat and boil to dissolve the soluble salt, cool to room temperature, transfer to a 100mL volumetric flask, dilute with water to the mark, and mix well.
A6.3.2 Absorption
A6.3.2.1 According to Table A1, take the test solution (A6.3.1.2) and place it in a 100mL conical flask. Table A1
Monument content, %
>0.020~0.070
>0.070~0.10
Test solution aliquot, mL
A6.3.2.2 Add 7 mL of sulfuric acid, dilute to 40 mL with water, add 5 mL of potassium iodide solution, 2 mL of stannous chloride solution, and mix each reagent thoroughly. Let stand for 2~3 minutes until the yellow color of the solution disappears. Add 5 mL of tartaric acid solution and let stand for 10 minutes. A6.3.2.3 Transfer 10.00 mL of copper reagent silver salt trifluoromethane solution into a 10 mL absorption tube, add 5 g of arsenic-free zinc particles into a conical flask, and immediately connect the arsenic hydrogen gas generation-absorption device according to Figure A1. A6.3.2.4 After 40 minutes of reaction, remove the airway tube, rinse the airway tube with a small amount of trichloromethane, combine the washing liquid in the absorption tube, and dilute it to 10.00mL with trichloromethane, and mix well.
A6.3.3 Measurement
GB/T3884.9—2000
Place part of the solution (A6.3.2.4) into a dry 1cm absorption tube, and measure its absorbance at a wavelength of 530nm using the copper reagent silver salt trichloromethane solution as a reference on a spectrophotometer. Find the corresponding arsenic on the working curve. A6.4 Drawing of the working curve.
Pipette 0, 2.00, 4.00, 6.00, 8.00, and 10.00mL of arsenic standard solution, place them in a group of 100mL conical flasks, add 6mL of ammonium ferric sulfate solution and 6mL of copper sulfate solution, and mix well. The following working curve is drawn according to A6.3.2.2~absorbance is used as the ordinate. A7
Analysis result expression
Calculate the percentage of arsenic according to formula (4):
As(%) =
Wherein: m2
(mz -- m,) . V. × 10--
the arsenic content of the test solution found on the working curve, g, the arsenic content of the blank solution of the test sample found on the working curve, g: the total volume of the test solution, mL;
V,-the volume of the test solution taken, mL,
the mass of the test sample, g.
The obtained result is expressed to three decimal places.
Allowable difference
The difference in the analysis results between laboratories should not be greater than the allowable difference listed in Table A2. Table A2
0.010~0.020
>0.020~0.040
>0.040~0.070
>0. 070~0.10
Appendix B
(Suggested Appendix)
Instrument Working Conditions
The working conditions of the AFS-220 dual-channel atomic fluorescence spectrometer are as shown in Table B1: Determination
Lamp current
Negative high voltage
Carrier gas flow plate
Shielding gas flow
Atomization temperature
16.3.3. With the amount of arsenic as the horizontal axis, X100
Addition time
Delay time
Sampling time1) Place in a 150mL beaker, add 0.1g potassium chlorate and the sample and mix well, add 10mL nitric acid and place on a hot plate to heat and decompose, repeatedly add small amounts of potassium nitrate until no monomeric sulfur is precipitated, continue to evaporate until nearly dry, cool slightly, add 5~8mL sulfuric acid along the wall of the cup and evaporate until thick smoke appears, remove and cool slightly. A6.3.1.2 Blow the cup with water, heat and boil to dissolve the soluble salt, cool to room temperature, transfer to a 100mL volumetric flask, dilute with water to the mark, and mix well.
A6.3.2 Absorption
A6.3.2.1 According to Table A1, take the test solution (A6.3.1.2) and place it in a 100mL conical flask. Table A1
Monument content, %
>0.020~0.070
>0.070~0.10
Test solution aliquot, mL
A6.3.2.2 Add 7 mL of sulfuric acid, dilute to 40 mL with water, add 5 mL of potassium iodide solution, 2 mL of stannous chloride solution, and mix each reagent thoroughly. Let stand for 2~3 minutes until the yellow color of the solution disappears. Add 5 mL of tartaric acid solution and let stand for 10 minutes. A6.3.2.3 Transfer 10.00 mL of copper reagent silver salt trifluoromethane solution into a 10 mL absorption tube, add 5 g of arsenic-free zinc particles into a conical flask, and immediately connect the arsenic hydrogen gas generation-absorption device according to Figure A1. A6.3.2.4 After 40 minutes of reaction, remove the airway tube, rinse the airway tube with a small amount of trichloromethane, combine the washing liquid in the absorption tube, and dilute it to 10.00mL with trichloromethane, and mix well.
A6.3.3 Measurement
GB/T3884.9—2000
Place part of the solution (A6.3.2.4) into a dry 1cm absorption tube, and measure its absorbance at a wavelength of 530nm using the copper reagent silver salt trichloromethane solution as a reference on a spectrophotometer. Find the corresponding arsenic on the working curve. A6.4 Drawing of the working curve.
Pipette 0, 2.00, 4.00, 6.00, 8.00, and 10.00mL of arsenic standard solution, place them in a group of 100mL conical flasks, add 6mL of ammonium ferric sulfate solution and 6mL of copper sulfate solution, and mix well. The following working curve is drawn according to A6.3.2.2~absorbance is used as the ordinate. A7
Analysis result expression
Calculate the percentage of arsenic according to formula (4):
As(%) =
Wherein: m2
(mz -- m,) . V. × 10--
the arsenic content of the test solution found on the working curve, g, the arsenic content of the blank solution of the test sample found on the working curve, g: the total volume of the test solution, mL;
V,-the volume of the test solution taken, mL,
the mass of the test sample, g.
The obtained result is expressed to three decimal places.
Allowable difference
The difference in the analysis results between laboratories should not be greater than the allowable difference listed in Table A2. Table A2
0.010~0.020
>0.020~0.040
>0.040~0.070
>0. 070~0.10
Appendix B
(Suggested Appendix)
Instrument Working Conditions
The working conditions of the AFS-220 dual-channel atomic fluorescence spectrometer are as shown in Table B1: Determination
Lamp current
Negative high voltage
Carrier gas flow plate
Shielding gas flow
Atomization temperature
16.3.3. With the amount of arsenic as the horizontal axis, X100
Addition time
Delay time
Sampling time
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