This standard specifies the determination method of phosphorus content in copper and copper alloys. This standard is applicable to the determination of phosphorus content in copper and copper alloys except for the phosphorus content of tin bronze. Determination range: 0.000 2% to 0.12%. GB/T 5121.2-1996 Chemical analysis method for copper and copper alloys Determination of phosphorus content GB/T5121.2-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis methods for copper and copper alloys-Determination of phosphorus content Copper and copper alloys-Determination of phosphorus content Part 1 Method 1 Scope
Determination of phosphorus content by molybdenum blue spectrophotometry
This standard specifies the method for determination of phosphorus content in copper and copper alloys. GB/T 5121.2:1996
Replaces GB5121.2
GB 5122. 9
GB 8002. 3 -- 87
GB 8002. 10
GIB 8550.12 87
This standard applies to the determination of phosphorus content in copper and copper alloys, except for the phosphorus content of tin bronze. Determination range: 0.0002% to 0.12%. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Standardization work guidelines for the preparation of chemical analysis methods GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products 3 Method summary
The sample is dissolved in mixed acid or nitric acid. In the nitric acid medium, phosphorus reacts with ammonium molybdate to form phosphomolybdic heteropolyacid. It is extracted with n-butanol-trimethylmethane and the phosphomolybdic heteropolyacid is reduced with stannous chloride to form molybdenum blue. The absorbance is measured at a wavelength of 630nm on a spectrophotometer. 4 Reagents
4.1 Boric acid.
4.2 n-butanol (p0.81g/mL).
4.3 Hydrofluoric acid (p1.13g/mL), high purity. 4.4 Perchloric acid (pl.67g/mL).
4.5 Hydrogen peroxide (30%).
4.6 Nitric acid (1+1).
4.7 Nitric acid (1.1mol/L): 74mL nitric acid (pl.42g/mL) add water to 1000mL. 4.8 Sulfuric acid (1+19).
4.9 Potassium permanganate solution (20g/L).
4.10 Sodium nitrite solution (100g/L). 4.11 Ammonium lead acid solution (50g/L): Weigh 50g ammonium molybdate [(NH)MO,Oz·4HzO and dissolve in 800mL hot water, cool. Add water to 1000mL, filter and use.
4.12 Mixed acid: Add 320mL nitric acid (p1.42g/mL) and 120mL hydrochloric acid (p1.19g/mL) to 560mL water and mix well. Approved by the State Administration of Technical Supervision on November 4, 1996 202
Implementation on April 1, 1997
GB/T5121.2-1996
4.13 Lifting agent: Mix 1 unit volume of n-butanol and 3 units volume of chloroform. 4.14 Stannous chloride solution (20g/L): Weigh 2g of stannous chloride (SnCl22H,0) in a 150mL beaker, add 12ml. hydrochloric acid (1+1), heat to dissolve, and cool. Dilute to 100mL with water. Prepare it when needed. 4.15 Phosphorus standard stock solution: Weigh 0.4394g potassium dihydrogen phosphate into a beaker, add 100ml nitric acid (1+5), stir to dissolve, transfer to a 1000ml volumetric flask, dilute to scale with water, and mix well. This solution contains 0.1mg phosphorus per mL. 4.16 Phosphorus standard solution: Transfer 10.00mL phosphorus standard stock solution into a 200mL volumetric flask, dilute to scale with water, and mix well. This solution contains 5μg phosphorus per mL.
5 Instruments
Spectrophotometer.
6 Analysis steps
6.1 Test materials
Weigh the sample according to Table 1, accurate to 0.0001g. Phosphorus content, %
0.00020~0.0010
0. 001 0~0. 005 0
>0. 005 0 ~ 0. 025
>0. 025~ 0. 060
>0. 060~0. 12
Sample amount·g
Carry out two independent determinations and take the average value. 6.2 Blank test
Carry out a blank test together with the sample.
6.3 Determination
6.3.1 Dissolution of sample. wwW.bzxz.Net
Amount of dissolved acid, mL
Dilution volume, mL
Volume of test solution, ml
6.3.1.1 Place the sample (6.1) in a 150ml beaker, add the mixed acid according to Table 1, cover with a table, heat to dissolve it completely, add 3 drops of hydrogen peroxide, boil for 1 min, wash the table blood with water, evaporate at low temperature until the solution becomes viscous (the contents of the beaker should be able to flow at this time). 6.3.1.2 Chrome bronze: Place the sample (6.1) in a 150ml polytetrafluoroethylene cup, add 10ml of the mixed acid, heat at low humidity to dissolve it; add 5 drops of hydrofluoric acid and 3ml of perchloric acid, evaporate at low temperature to nearly dryness (solid after cooling). 6.3.1.3 White copper: Place the sample (6.1) in a 150ml beaker, add 10ml of nitric acid (4.6), cover with Table III, heat to dissolve it, and boil to remove all nitrogen oxides. Add potassium permanganate solution until the solution turns red, and add 2 drops in excess, boil for 1 minute, add sodium nitrite solution until the potassium permanganate color fades, and add 1 drop in excess, wash the watch glass with water, evaporate at low temperature until the solution is viscous (the contents of the beaker should be able to flow at this time), and cool.
6.3.2 Dissolving salts
6.3.2.1 Add 10ml nitric acid (4.7) and heat to dissolve the salts, and cool. Dilute the solution directly or with nitric acid (4.7) according to Table 1, and take the test solution into a 125ml separatory funnel, wash the beaker with 15ml nitric acid (4.7) in batches, or add 15ml nitric acid (4.7) and add it to the treasure solution.
6.3.2.2 Chrome bronze: Add 10ml nitric acid (4.7), 5 drops of sodium nitrite solution, cover the watch glass, heat to a slight boil for 1min, remove and cool slightly. Add 5 drops of hydrofluoric acid and mix well. Add 1 gram of boric acid and mix well. Dilute the solution directly or according to the volume of nitric acid (4.7) in Table 1, take the test solution tube and place it in a 203
GB/T 5121.2---1996
125mL separatory funnel, wash the beaker with 15mL nitric acid (4.7) in batches or add 15ml nitric acid (4.7) and add it to the main solution. 6.3.2.3 Silicon bronze and silicon brass: Add 10mL nitric acid (4.7) and 5 drops of cyanofluoric acid, heat to dissolve the salts, remove and cool slightly, add 1g of acid, and mix with a spoon. Dilute the solution directly or according to the volume of nitric acid (4.7) in Table 1, take the test solution and place it in a 125mL separatory funnel, wash the beaker with 15mL nitric acid (4.7) in batches or add 15ml nitric acid (4.7) and add it to the main solution. 6.3.3 Extraction
6.3.3.1 Add 5mL of ammonium molybdate solution, mix well, and let stand for 5min. Add 2mL of n-butyl alcohol, shake the separatory funnel to dissolve it in water. Add 10mL of extractant and shake for 30s. After standing and stratifying, transfer the organic phase to another separatory funnel. Add 5mL of extractant to the aqueous phase, shake for 30s, and after standing and stratifying, combine the organic phases and discard the aqueous phase. 6.3.3.2 Add 5mL of sulfuric acid to the organic phase, shake for 30s, and after standing and stratifying, transfer the organic phase to a 25ml dry volumetric flask and dilute to the mark with n-butyl alcohol, add 3 drops of stannous chloride solution, and mix well. 6.3.4 Measurement
Transfer part of the solution to a dry 2cm absorbent tube, and measure the absorbance at a wavelength of 630nm on a spectrophotometer using the blank solution accompanying the sample as a reference. Find the corresponding phosphorus content from the working curve. 6.4 Drawing of working curve
6.4.1 Take 0, 0.80, 2.003.00, 4.00, 5.00mL of phosphorus standard solution and place them in a set of 125mL separating funnels. Add 25mL of nitric acid (4.7) and proceed as per 6.3.3. 6.4.2 Transfer part of the solution into a dry 2cm absorption III and measure its absorbance at a wavelength of 630nm using the reagent blank as reference. Draw the working curve with the phosphorus content as the abscissa and the absorbance as the ordinate. 7 Expression of analysis results
Calculate the percentage of phosphorus according to formula (1):
mi - V,× 10-5
P(%) =
Where: ml—phosphorus content found on the working curve, μg; V. Total volume of test solution, mL;
Volume of test solution, ml.;
Mass of test material, 8.
The result is expressed to two decimal places. If the phosphorus content is less than 0.When the value is less than 10%, it shall be expressed to 3 decimal places; when it is less than 0.010%, it shall be expressed to 4 decimal places; when it is less than 0.0010%, it shall be expressed to 5 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
0. 000 20 ~~0. 000 40
>0. 000 40~ 0. 001 0
>0. 001 0~0. 002 0
≥0. 002 0 ~ 0. 005 0
≥0. 005 0 ~ 0. 010
9 range
Phosphorus content
0.010~-0.025
0.025~0.060
0, 060~~0.12
GB/T5121.2-1996
Table 2 (end)
Part II Method 2
Determination of phosphorus content by spectrophotometry with vanadium molybdenum yellow
This standard specifies the method for determining the phosphorus content in copper and copper alloys. This standard is applicable to the determination of phosphorus content in tin bronze. Determination range: 0.010%~0.50%. 10 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Standardization work guidelines for the preparation of chemical analysis methods GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products GB6379-86 Precision of test methods The repeatability and reproducibility of standard test methods are determined through inter-laboratory tests 11 Method summary
The sample is dissolved in mixed acid. In nitric acid medium, phosphorus reacts with ammonium vanadate and ammonium molybdate to form a yellow complex of phosphorus molybdenum vanadium heteropoly acid. Its absorbance is measured at a wavelength of 430nm by a spectrophotometer. 12 Reagents
12.1 Pure copper (phosphorus content not more than 0.0002%). 12.2 Mixed acid: Add 320mL nitric acid (ol.42g/ml.) and 120mL hydrochloric acid (pl.i9g/ml.) to 560mL water, and mix well. 12.3 Hydrogen peroxide (1+9)
12.4 Ammonium vanadate solution (2.5g/1.): Weigh 2.5g ammonium metavanadate, dissolve in 500mL hot water, and cool after complete dissolution. Slowly add 20mL nitric acid (1+1) under constant stirring, dilute to 1000mL with water, and mix well. 12.5 Ammonium molybdate solution (100g/L): Weigh 100g ammonium molybdate L(NH)sMo,O24HO, dissolve in 800ml hot water, cool. Dilute to 1000mL with water, mix well, and filter. Store in a plastic bottle. 12.6 Phosphorus standard solution: Weigh 0.4394g potassium dihydrogen phosphate into a beaker, add 100mL nitric acid (1+5), stir to dissolve. Transfer to a 1000mL volumetric flask, dilute to scale with water, mix well, this solution contains 0.1mg phosphorus per ml. 13 Instruments
Spectrophotometer.
14 Analysis steps
14.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. 205
Phosphorus content, %
0. 010~~0. 040
0.040~0.080
>0.080~0.40
>0. 40~~0. 50
Sample amount, g
GB/T 5121. 2- 1996
Mixed acid amount, mL
Carry out two independent determinations and take the average value. 14.2 Blank test
Dilution volume, mL
Weigh the same amount of pure copper as the sample according to Table 3 and carry out a blank test together with the sample. 14.3 Determination
Take the test solution by volume, ml
Add the mixed acid, ml.
14.3.1 Place the test material (14.1) in a 150mL beaker, add the mixed acid according to Table 3, cover with table blood, heat at low temperature until the remaining solution is completely dissolved, remove and wash the table III and the wall of the beaker with a small amount of water, add 1mL of hydrogen peroxide, and mix well. Cover with table blood and heat to a slight boil for 34 minutes, remove and cool to room temperature. 14.3.2 Dilute the volume with water according to Table 3 and mix well. When the phosphorus content is not more than 0.08%, use a dry pipette to transfer 25mL of the test solution into a 50mL volumetric flask as the color developing solution, and the original test solution is the compensation solution.
When the phosphorus content is more than 0.08%: transfer 10.00mL of the test solution in two portions, place them in 50mL volumetric flasks respectively, and add the mixed acid according to Table 3 to each. 14.3.3 Add 5.0 mL of ammonium vanadate solution to the color-developing solution and the compensation solution at the same time. 14.3.4 Add 10 mL of ammonium molybdate solution to the color-developing solution, dilute to the mark with water, and mix. Let stand for 15 minutes. Dilute the compensation solution to the mark with water and mix.
14.3.5 Transfer part of the solution to a 2 cm absorption III, and measure the absorbance at a wavelength of 430 nm using the compensation solution as a reference on a spectrophotometer.
14.3.6 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding phosphorus amount from the working curve. 14.4 Drawing of working curve
14.4.1 Weigh 6 portions of 1.000g pure copper and place them in a group of 150mL beakers. Add 0, 0.50, 1.00, 2.00, 3.00.4.00mL of phosphorus standard solution in turn, add 15mL of mixed acid, cover with Table III, heat at low temperature until completely dissolved, remove and wash the table and the wall of the cup with a small amount of water, add 1mL of hydrogen peroxide, and mix. Cover with Table III and heat to a slight boil for 3 to 4 minutes, remove and cool to room temperature. 14.4.2 Add 5.0mL of ammonium vanadate solution and 10mL of ammonium molybdate solution, transfer to a 50mL volumetric flask, dilute with water to the scale and mix well. Let stand for 15 minutes.
14.4.3 Pipette part of the solution into 2 cm of absorbent blood, use the compensation solution as reference, measure the absorbance at a wavelength of 430 nm on the spectrophotometer, and draw a working curve with the phosphorus content as the horizontal axis and the absorbance as the vertical axis. 15 Expression of analysis results
Calculate the percentage of phosphorus according to formula (2):
m: -V. X 10-3
P(%) =
Where: m.--phosphorus content found from the working curve, mg; V.--total volume of test solution, mL;
V.--volume of test solution taken, mL.;
ma--mass of the sample, g.
× 100
The result is expressed to two decimal places; if the phosphorus content is less than 0.10%, it is expressed to three decimal places. 206
Precision
GB/T 5121. 2
The precision of this standard was determined by the joint test results of 8 laboratories (see Appendix A) at 8 levels selected in 1993: see Table 4 for precision.
Level rangem
0. 010~~0. 50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision test2-1996
Table 2 (end)
Part II Method 2
Determination of phosphorus content by vanadium molybdenum yellow spectrophotometry
This standard specifies the method for determining the phosphorus content in copper and copper alloys. This standard is applicable to the determination of phosphorus content in tin bronze. Determination range: 0.010% to 0.50%. 10 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Standardization work guidelines for the preparation of chemical analysis methods GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products GB6379-86 Precision of test methods The repeatability and reproducibility of standard test methods are determined through inter-laboratory tests 11 Method summary
The sample is dissolved in mixed acid. In nitric acid medium, phosphorus reacts with ammonium vanadate and ammonium molybdate to form a yellow complex of phosphorus molybdenum vanadium heteropoly acid. Its absorbance is measured at a wavelength of 430nm by a spectrophotometer. 12 Reagents
12.1 Pure copper (phosphorus content not more than 0.0002%). 12.2 Mixed acid: Add 320mL nitric acid (ol.42g/ml.) and 120mL hydrochloric acid (pl.i9g/ml.) to 560mL water, and mix well. 12.3 Hydrogen peroxide (1+9)
12.4 Ammonium vanadate solution (2.5g/1.): Weigh 2.5g ammonium metavanadate, dissolve in 500mL hot water, and cool after complete dissolution. Slowly add 20mL nitric acid (1+1) under constant stirring, dilute to 1000mL with water, and mix well. 12.5 Ammonium molybdate solution (100g/L): Weigh 100g ammonium molybdate L(NH)sMo,O24HO, dissolve in 800ml hot water, cool. Dilute to 1000mL with water, mix well, and filter. Store in a plastic bottle. 12.6 Phosphorus standard solution: Weigh 0.4394g potassium dihydrogen phosphate into a beaker, add 100mL nitric acid (1+5), stir to dissolve. Transfer to a 1000mL volumetric flask, dilute to scale with water, mix well, this solution contains 0.1mg phosphorus per ml. 13 Instruments
Spectrophotometer.
14 Analysis steps
14.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. 205
Phosphorus content, %
0. 010~~0. 040
0.040~0.080
>0.080~0.40
>0. 40~~0. 50
Sample amount, g
GB/T 5121. 2- 1996
Mixed acid amount, mL
Carry out two independent determinations and take the average value. 14.2 Blank test
Dilution volume, mL
Weigh the same amount of pure copper as the sample according to Table 3 and carry out a blank test together with the sample. 14.3 Determination
Take the test solution by volume, ml
Add the mixed acid, ml.
14.3.1 Place the test material (14.1) in a 150mL beaker, add the mixed acid according to Table 3, cover with table blood, heat at low temperature until the remaining solution is completely dissolved, remove and wash the table III and the wall of the beaker with a small amount of water, add 1mL of hydrogen peroxide, and mix well. Cover with table blood and heat to a slight boil for 34 minutes, remove and cool to room temperature. 14.3.2 Dilute the volume with water according to Table 3 and mix well. When the phosphorus content is not more than 0.08%, use a dry pipette to transfer 25mL of the test solution into a 50mL volumetric flask as the color developing solution, and the original test solution is the compensation solution.
When the phosphorus content is more than 0.08%: transfer 10.00mL of the test solution in two portions, place them in 50mL volumetric flasks respectively, and add the mixed acid according to Table 3 to each. 14.3.3 Add 5.0 mL of ammonium vanadate solution to the color-developing solution and the compensation solution at the same time. 14.3.4 Add 10 mL of ammonium molybdate solution to the color-developing solution, dilute to the mark with water, and mix. Let stand for 15 minutes. Dilute the compensation solution to the mark with water and mix.
14.3.5 Transfer part of the solution to a 2 cm absorption III, and measure the absorbance at a wavelength of 430 nm using the compensation solution as a reference on a spectrophotometer.
14.3.6 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding phosphorus amount from the working curve. 14.4 Drawing of working curve
14.4.1 Weigh 6 portions of 1.000g pure copper and place them in a group of 150mL beakers. Add 0, 0.50, 1.00, 2.00, 3.00.4.00mL of phosphorus standard solution in turn, add 15mL of mixed acid, cover with Table III, heat at low temperature until completely dissolved, remove and wash the table and the wall of the cup with a small amount of water, add 1mL of hydrogen peroxide, and mix. Cover with Table III and heat to a slight boil for 3 to 4 minutes, remove and cool to room temperature. 14.4.2 Add 5.0mL of ammonium vanadate solution and 10mL of ammonium molybdate solution, transfer to a 50mL volumetric flask, dilute with water to the scale and mix well. Let stand for 15 minutes.
14.4.3 Pipette part of the solution into 2 cm of absorbent blood, use the compensation solution as reference, measure the absorbance at a wavelength of 430 nm on the spectrophotometer, and draw a working curve with the phosphorus content as the horizontal axis and the absorbance as the vertical axis. 15 Expression of analysis results
Calculate the percentage of phosphorus according to formula (2):
m: -V. X 10-3
P(%) =
Where: m.--phosphorus content found from the working curve, mg; V.--total volume of test solution, mL;
V.--volume of test solution taken, mL.;
ma--mass of the sample, g.
× 100
The result is expressed to two decimal places; if the phosphorus content is less than 0.10%, it is expressed to three decimal places. 206
Precision
GB/T 5121. 2
The precision of this standard was determined by the joint test results of 8 laboratories (see Appendix A) at 8 levels selected in 1993: see Table 4 for precision.
Level rangem
0. 010~~0. 50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision test2-1996
Table 2 (end)
Part II Method 2
Determination of phosphorus content by vanadium molybdenum yellow spectrophotometry
This standard specifies the method for determining the phosphorus content in copper and copper alloys. This standard is applicable to the determination of phosphorus content in tin bronze. Determination range: 0.010% to 0.50%. 10 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Standardization work guidelines for the preparation of chemical analysis methods GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products GB6379-86 Precision of test methods The repeatability and reproducibility of standard test methods are determined through inter-laboratory tests 11 Method summary
The sample is dissolved in mixed acid. In nitric acid medium, phosphorus reacts with ammonium vanadate and ammonium molybdate to form a yellow complex of phosphorus molybdenum vanadium heteropoly acid. Its absorbance is measured at a wavelength of 430nm by a spectrophotometer. 12 Reagents
12.1 Pure copper (phosphorus content not more than 0.0002%). 12.2 Mixed acid: Add 320mL nitric acid (ol.42g/ml.) and 120mL hydrochloric acid (pl.i9g/ml.) to 560mL water, and mix well. 12.3 Hydrogen peroxide (1+9)
12.4 Ammonium vanadate solution (2.5g/1.): Weigh 2.5g ammonium metavanadate, dissolve in 500mL hot water, and cool after complete dissolution. Slowly add 20mL nitric acid (1+1) under constant stirring, dilute to 1000mL with water, and mix well. 12.5 Ammonium molybdate solution (100g/L): Weigh 100g ammonium molybdate L(NH)sMo,O24HO, dissolve in 800ml hot water, cool. Dilute to 1000mL with water, mix well, and filter. Store in a plastic bottle. 12.6 Phosphorus standard solution: Weigh 0.4394g potassium dihydrogen phosphate into a beaker, add 100mL nitric acid (1+5), stir to dissolve. Transfer to a 1000mL volumetric flask, dilute to scale with water, mix well, this solution contains 0.1mg phosphorus per ml. 13 Instruments
Spectrophotometer.
14 Analysis steps
14.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. 205
Phosphorus content, %
0. 010~~0. 040
0.040~0.080
>0.080~0.40
>0. 40~~0. 50
Sample amount, g
GB/T 5121. 2- 1996
Mixed acid amount, mL
Carry out two independent determinations and take the average value. 14.2 Blank test
Dilution volume, mL
Weigh the same amount of pure copper as the sample according to Table 3 and carry out a blank test together with the sample. 14.3 Determination
Take the test solution by volume, ml
Add the mixed acid, ml.
14.3.1 Place the test material (14.1) in a 150mL beaker, add the mixed acid according to Table 3, cover with table blood, heat at low temperature until the remaining solution is completely dissolved, remove and wash the table III and the wall of the beaker with a small amount of water, add 1mL of hydrogen peroxide, and mix well. Cover with table blood and heat to a slight boil for 34 minutes, remove and cool to room temperature. 14.3.2 Dilute the volume with water according to Table 3 and mix well. When the phosphorus content is not more than 0.08%, use a dry pipette to transfer 25mL of the test solution into a 50mL volumetric flask as the color developing solution, and the original test solution is the compensation solution.
When the phosphorus content is more than 0.08%: transfer 10.00mL of the test solution in two portions, place them in 50mL volumetric flasks respectively, and add the mixed acid according to Table 3 to each. 14.3.3 Add 5.0 mL of ammonium vanadate solution to the color-developing solution and the compensation solution at the same time. 14.3.4 Add 10 mL of ammonium molybdate solution to the color-developing solution, dilute to the mark with water, and mix. Let stand for 15 minutes. Dilute the compensation solution to the mark with water and mix.
14.3.5 Transfer part of the solution to a 2 cm absorption III, and measure the absorbance at a wavelength of 430 nm using the compensation solution as a reference on a spectrophotometer.
14.3.6 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding phosphorus amount from the working curve. 14.4 Drawing of working curve
14.4.1 Weigh 6 portions of 1.000g pure copper and place them in a group of 150mL beakers. Add 0, 0.50, 1.00, 2.00, 3.00.4.00mL of phosphorus standard solution in turn, add 15mL of mixed acid, cover with Table III, heat at low temperature until completely dissolved, remove and wash the table and the wall of the cup with a small amount of water, add 1mL of hydrogen peroxide, and mix. Cover with Table III and heat to a slight boil for 3 to 4 minutes, remove and cool to room temperature. 14.4.2 Add 5.0mL of ammonium vanadate solution and 10mL of ammonium molybdate solution, transfer to a 50mL volumetric flask, dilute with water to the scale and mix well. Let stand for 15 minutes.
14.4.3 Pipette part of the solution into 2 cm of absorbent blood, use the compensation solution as reference, measure the absorbance at a wavelength of 430 nm on the spectrophotometer, and draw a working curve with the phosphorus content as the horizontal axis and the absorbance as the vertical axis. 15 Expression of analysis results
Calculate the percentage of phosphorus according to formula (2):
m: -V. X 10-3
P(%) =
Where: m.--phosphorus content found from the working curve, mg; V.--total volume of test solution, mL;
V.--volume of test solution taken, mL.;
ma--mass of the sample, g.
× 100
The result is expressed to two decimal places; if the phosphorus content is less than 0.10%, it is expressed to three decimal places. 206
Precision
GB/T 5121. 2
The precision of this standard was determined by the joint test results of 8 laboratories (see Appendix A) at 8 levels selected in 1993: see Table 4 for precision.
Level rangem
0. 010~~0. 50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision testPlace 4394g potassium dihydrogen phosphate in a beaker, add 100mL nitric acid (1+5), stir to dissolve. Transfer to a 1000mL volumetric flask, dilute to scale with water, mix well, this solution contains 0.1mg phosphorus per ml. 13 Instruments
Spectrophotometer.
14 Analysis steps
14.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. 205
Phosphorus content, %
0. 010~~0. 040
0.040~0.080
>0.080~0.40
>0. 40~~0. 50
Sample amount, g
GB/T 5121. 2- 1996
Mixed acid amount, mL
Carry out two independent determinations and take the average value. 14.2 Blank test
Dilution volume, mL
Weigh the same amount of pure copper as the sample according to Table 3 and carry out a blank test together with the sample. 14.3 Determination
Take the test solution by volume, ml
Add the mixed acid, ml.
14.3.1 Place the test material (14.1) in a 150mL beaker, add the mixed acid according to Table 3, cover with table blood, heat at low temperature until the remaining solution is completely dissolved, remove and wash the table III and the wall of the beaker with a small amount of water, add 1mL of hydrogen peroxide, and mix well. Cover with table blood and heat to a slight boil for 34 minutes, remove and cool to room temperature. 14.3.2 Dilute the volume with water according to Table 3 and mix well. When the phosphorus content is not more than 0.08%, use a dry pipette to transfer 25mL of the test solution into a 50mL volumetric flask as the color developing solution, and the original test solution is the compensation solution.
When the phosphorus content is more than 0.08%: transfer 10.00mL of the test solution in two portions, place them in 50mL volumetric flasks respectively, and add the mixed acid according to Table 3 to each. 14.3.3 Add 5.0 mL of ammonium vanadate solution to the color-developing solution and the compensation solution at the same time. 14.3.4 Add 10 mL of ammonium molybdate solution to the color-developing solution, dilute to the mark with water, and mix. Let stand for 15 minutes. Dilute the compensation solution to the mark with water and mix.
14.3.5 Transfer part of the solution to a 2 cm absorption III, and measure the absorbance at a wavelength of 430 nm using the compensation solution as a reference on a spectrophotometer.
14.3.6 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding phosphorus amount from the working curve. 14.4 Drawing of working curve
14.4.1 Weigh 6 portions of 1.000g pure copper and place them in a group of 150mL beakers. Add 0, 0.50, 1.00, 2.00, 3.00.4.00mL of phosphorus standard solution in turn, add 15mL of mixed acid, cover with Table III, heat at low temperature until completely dissolved, remove and wash the table and the wall of the cup with a small amount of water, add 1mL of hydrogen peroxide, and mix. Cover with Table III and heat to a slight boil for 3 to 4 minutes, remove and cool to room temperature. 14.4.2 Add 5.0mL of ammonium vanadate solution and 10mL of ammonium molybdate solution, transfer to a 50mL volumetric flask, dilute with water to the scale and mix well. Let stand for 15 minutes.
14.4.3 Pipette part of the solution into 2 cm of absorbent blood, use the compensation solution as reference, measure the absorbance at a wavelength of 430 nm on the spectrophotometer, and draw a working curve with the phosphorus content as the horizontal axis and the absorbance as the vertical axis. 15 Expression of analysis results
Calculate the percentage of phosphorus according to formula (2):
m: -V. X 10-3
P(%) =
Where: m.--phosphorus content found from the working curve, mg; V.--total volume of test solution, mL;
V.--volume of test solution taken, mL.;
ma--mass of the sample, g.
× 100
The result is expressed to two decimal places; if the phosphorus content is less than 0.10%, it is expressed to three decimal places. 206
Precision
GB/T 5121. 2
The precision of this standard was determined by the joint test results of 8 laboratories (see Appendix A) at 8 levels selected in 1993: see Table 4 for precision.
Level rangem
0. 010~~0. 50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision testPlace 4394g potassium dihydrogen phosphate in a beaker, add 100mL nitric acid (1+5), stir to dissolve. Transfer to a 1000mL volumetric flask, dilute to scale with water, mix well, this solution contains 0.1mg phosphorus per ml. 13 Instruments
Spectrophotometer.
14 Analysis steps
14.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. 205
Phosphorus content, %
0. 010~~0. 040
0.040~0.080
>0.080~0.40
>0. 40~~0. 50
Sample amount, g
GB/T 5121. 2- 1996
Mixed acid amount, mL
Carry out two independent determinations and take the average value. 14.2 Blank test
Dilution volume, mL
Weigh the same amount of pure copper as the sample according to Table 3 and carry out a blank test together with the sample. 14.3 Determination
Take the test solution by volume, ml
Add the mixed acid, ml.
14.3.1 Place the test material (14.1) in a 150mL beaker, add the mixed acid according to Table 3, cover with table blood, heat at low temperature until the remaining solution is completely dissolved, remove and wash the table III and the wall of the beaker with a small amount of water, add 1mL of hydrogen peroxide, and mix well. Cover with table blood and heat to a slight boil for 34 minutes, remove and cool to room temperature. 14.3.2 Dilute the volume with water according to Table 3 and mix well. When the phosphorus content is not more than 0.08%, use a dry pipette to transfer 25mL of the test solution into a 50mL volumetric flask as the color developing solution, and the original test solution is the compensation solution.
When the phosphorus content is more than 0.08%: transfer 10.00mL of the test solution in two portions, place them in 50mL volumetric flasks respectively, and add the mixed acid according to Table 3 to each. 14.3.3 Add 5.0 mL of ammonium vanadate solution to the color-developing solution and the compensation solution at the same time. 14.3.4 Add 10 mL of ammonium molybdate solution to the color-developing solution, dilute to the mark with water, and mix. Let stand for 15 minutes. Dilute the compensation solution to the mark with water and mix.
14.3.5 Transfer part of the solution to a 2 cm absorption III, and measure the absorbance at a wavelength of 430 nm using the compensation solution as a reference on a spectrophotometer.
14.3.6 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding phosphorus amount from the working curve. 14.4 Drawing of working curve
14.4.1 Weigh 6 portions of 1.000g pure copper and place them in a group of 150mL beakers. Add 0, 0.50, 1.00, 2.00, 3.00.4.00mL of phosphorus standard solution in turn, add 15mL of mixed acid, cover with Table III, heat at low temperature until completely dissolved, remove and wash the table and the wall of the cup with a small amount of water, add 1mL of hydrogen peroxide, and mix. Cover with Table III and heat to a slight boil for 3 to 4 minutes, remove and cool to room temperature. 14.4.2 Add 5.0mL of ammonium vanadate solution and 10mL of ammonium molybdate solution, transfer to a 50mL volumetric flask, dilute with water to the scale and mix well. Let stand for 15 minutes.
14.4.3 Pipette part of the solution into 2 cm of absorbent blood, use the compensation solution as reference, measure the absorbance at a wavelength of 430 nm on the spectrophotometer, and draw a working curve with the phosphorus content as the horizontal axis and the absorbance as the vertical axis. 15 Expression of analysis results
Calculate the percentage of phosphorus according to formula (2):
m: -V. X 10-3
P(%) =
Where: m.--phosphorus content found from the working curve, mg; V.--total volume of test solution, mL;
V.--volume of test solution taken, mL.;
ma--mass of the sample, g.
× 100
The result is expressed to two decimal places; if the phosphorus content is less than 0.10%, it is expressed to three decimal places. 206
Precision
GB/T 5121. 2
The precision of this standard was determined by the joint test results of 8 laboratories (see Appendix A) at 8 levels selected in 1993: see Table 4 for precision.
Level rangem
0. 010~~0. 50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision test50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision test50
Repeatability
rz0.00369+0.02673m
ReproducibilityR
R=0.00567+0.038 15
If the difference between two independent test results exceeds the repeatability and reproducibility values ​​calculated by the precision function listed in the table, the two results are considered to be suspicious values.
Laboratory
0,0190
GB/T 5121. 2 1996
Appendix A
(Standard Appendix)
Original data of precision test
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