GB/T 4103.1-2000 Chemical analysis methods for lead and lead alloys - Determination of tin content
Some standard content:
GB/T 4103. 1--2000
This standard adopts two chemical analysis methods to determine the tin content in lead and lead alloys. Method 1 is a revision of GB/T4103.2-1983 "Chemical analysis method for lead-based alloys - Catechol violet-cetyltrimethylammonium bromide photometric method for determination of tin content" and GB/T472.6-1984 "Chemical analysis method for lead ingots - Catechol violet-cetyltrimethylammonium bromide spectrophotometric method for determination of tin content"; Method 2 is a reconfirmation of GB/T4103.1-1983 "Chemical analysis method for lead-based alloys - iodine titration method for determination of tin content", with only editorial changes. This standard complies with:
GB/T1.1--1993 Guidelines for Standardization Unit 1: Rules for Drafting and Presenting Standards Part 1: Basic Provisions for Standardization
GB/T1.4--1988 Guidelines for Standardization Provisions for the Preparation of Chemical Analysis Methods GB/T1467-1978 General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products GB/T7729--1987 General Rules for Spectrophotometric Methods for Chemical Analysis of Metallurgical Products G3/T17433--1998 Basic Terminology for Chemical Analysis of Metallurgical Products This standard replaces GB/T4103.1-1983, GB/T4103.2--1983, GB/T472.6--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 Standards and Quality Research Institute. This standard is drafted by Shenyang Smelter and Northwest Copper Processing Plant of Baiyin Nonferrous Metals Company. Method 1 of this standard was drafted by Northwest Copper Processing Plant of Baiyin Nonferrous Metals Company; Method 2 was drafted by Beijing Nonferrous Metals Smelting Plant. The main drafters of Method 1 of this standard are Pan Feng; the main drafters of Method 2 are Huang Meilin and Li Jihe. 99
1 Scope
National Standard of the People's Republic of China
Chemical analysis methods of lead and lead alloys
Determination of tin content
Methods for chemical analysis of lead and lead alloys--- Determination of tin contentGB/T 4103. 1 - 2000
Replaces GB/T 4103.1-- 1983
GB/F 4103. 2 -
GB/T 472- 6 -- 1984
Method 1 Determination of tin content by catechol violet-cetyltrimethylammonium bromide spectrophotometry This standard specifies the determination method of tin content in lead and lead alloys This standard is applicable to the determination of tin content in lead and lead alloys. Determination range: 0.00050%~1.00%. 2 Summary of the method
The sample is dissolved with nitric acid and citric acid. Lead is separated into lead sulfate precipitation. In the nitric acid-citric acid medium, add o-phenol violet, lysine + hexaalkyl trimethyl ammonium to form a complex with tin, and measure its absorbance at a wavelength of 660nm on a spectrophotometer. 3 Reagents
3. 1 Sulfuric acid (pl.84 g/mL).
3.2 Nitric acid (pl.42 g/mL).
3.3 Sulfuric acid (1+4).
3.4 Sulfuric acid (1+99).
3.5 Nitric acid (1+2).
3.6 Sample dissolving acid: Weigh 25g citric acid (C, HgO,·Hz0) and dissolve it in 100mL nitric acid (3-+7). 3.7 Mixed acid: Weigh 50g citric acid (CHO, ·H2O), dissolve in water, transfer to a 1000mL volumetric flask, add 50ml nitric acid (3.2), dilute to scale with water, and mix. 3.8 Lactic acid (1+4).
3.9 Citric acid (CHO, ·HO) solution (250g/1). 3.10 Thiourea solution (20g/L).
3.11 Ascorbic acid solution (40g/L).
3.12 Catechol violet solution (0.18g/1.). 3.13 Cetyltrimethylammonium bromide (CTMAB) solution (0.3g/L): Dissolve in hot water. If precipitation occurs at low temperature, heat and dissolve before continued use.
3.14 Disodium ethylenediaminetetraacetic acid (CuH,N,O,Na·2H,), also known as NazEDTA) solution (37g/L.). 3.15 Standard tin storage solution: Weigh 0.2500g pure tin, place in a 200mL beaker, cover with Table III, add 5ml hydrochloric acid (1→!), add hydrogen peroxide (p1.10g/mL) dropwise to dissolve the tin completely, boil to decompose hydrogen peroxide. Cool. Wash Table III and the wall of the beaker with water, transfer to a 500mL volumetric flask, add 20g citric acid (CH),·H0), 100ml nitric acid (3.2), mix well, dissolve the citric acid. Dilute with water to the scale of 100, and mix with a spoon. This solution contains 500μg tin in 1mL. GB/T 4103. 1-2000
3.16 Tin standard solution: Pipette 5.00 ml of tin standard storage solution (3.15) into a 500 ml volumetric bottle, dilute to the mark with mixed acid (3.7), mix with a spoon, and 1 ml of this solution contains 5 ug of tin. 4 Instruments
Spectrophotometer.
5 Analysis steps
5.1 Test materials
Weigh the sample according to Table 1, accurate to 0.0001 g. Table 1
Tin content.%
0. 000 50--0. 002 5
0. 002 5 --0. 005 0
:0. 005 0-- 0. 025
>0. 025~-0. 12
2>0. 12~0. 50
2>0. 50 --1, 00
Two independent measurements were carried out and the average value was taken. 5.2 Blanking test
Acid for dissolution, mL
Dissolving acid
Nitric acid (3.5)
Division ratio
50/100
25/100
10/100
10/200
Acid volume after distillation.ml
Weigh 2 samples. When one of them is carried out to 5.3.7, add 0.5mL NaEDTA solution to the solution and keep it as a reference drop solution.
5.3 Determination
5.3.1 Place the sample (5.1) in a 200mL beaker. If the tin content is not more than 0.0025%, weigh 2 samples; if the tin content is more than 0.0025, weigh 1 sample. Add dissolving acid and nitric acid (3.5) according to Table 1, heat at low temperature to dissolve, boil to remove nitrogen oxides, and cool. Wash the cup and the wall with water, add water to a volume of about 30ml.
5.3.2 Add 20ml sulfuric acid (3.3), mix well, and cool. Filter the filtrate into a 200ml beaker with a slow quantitative filter paper. For the sample with a tin content of 0.0025%, filter it into the corresponding volumetric flask according to Table 1, wash the beaker and precipitate with sulfuric acid (3.4) 78 times, and dilute to the scale with sulfuric acid (3.14), and mix.
5.3.3 Take 2 portions of the full amount of the test solution according to Table 1, and proceed directly according to 5.3.4. For the sample with a tin content greater than 0.0025%, collect 2 portions and test them in 1200ml beakers, and add dissolving acid and sulfuric acid (3.1) according to Table 1. 5.3.4 Heat and evaporate until the solution just produces foam, cover with beaker III, move to high temperature to evaporate and dissolve white smoke. Use a pipette to add about 0.5ml of nitric acid (3.2) along the wall of the cup. Mix. When the brown smoke disappears, remove the beaker. Cool slightly, wash the beaker with 1ml of nitric acid (3.2), heat and mix. Evaporate until about 1ml, then add about 0.3ml of nitric acid (3.2). Mix well, and heat until it is white. Repeat the nitric acid addition operation to completely carbonize the citric acid in the presence of a small amount of sulfuric acid. Evaporate until there is no sulfuric acid smoke at the bottom and wall of the cup, and then heat the wall of the cup for 30 minutes. 5.3.5 Add different amounts of citric acid solution according to the antimony content in the test solution. If the amount is not large (4.5mg), add 4ml; if the antimony amount is 4.5~10.8mg, add 5ml; if the amount is greater than 10.8mg, add 6ml. Heat to dissolve the salt and cool.
5.3.6 Transfer the solution into a 50ml volumetric flask pre-filled with 6ml of mixed acid, 2.5ml of sulfur solution, 5.3.7 Add 0.5ml of NaEDTA solution (this is the supplement solution) to one portion of the test solution. Directly connect the other portion of the test solution to the flow path 5.3.8. 5.3.8 Add 2.5ml of ascorbic acid solution, 2.5ml of lactic acid, 5ml of o-phthalic acid violet solution, and 3ml of phthalic acid violet solution to the solution.TMAP solution, each reagent must be mixed. Dilute with water to the scale, mix. Place the cake for 10 minutes. GB/T 4103.1 5.3.9 Pipette part of the solution into a 2 cm absorbent tube, use the compensation solution (5.3.7) as a reference, measure its absorbance at a wavelength of 660 nm on a spectrophotometer, and find the corresponding tin amount from the working curve. 5.4 Drawing of working curve
5.4.1 Transfer 0, 1.00, 2.00, 3.00, 4.00, 5.00mL of tin standard solution to a set of 50mL volumetric flasks, add 6.0, 5.0, 4.0, 3.0, 2.0, 1.0mL of mixed acid and 4mL of citric acid solution respectively, and proceed as per 5.3.8. 5.4.2 Transfer part of the solution into a 2cm absorption dish, use the reagent cavity as reference, and measure its absorbance at a wavelength of 660nm on a spectrophotometer. Draw the working curve with the amount of tin as the horizontal axis and the absorbance as the vertical axis. 6 Expression of analysis results
Calculate the percentage of tin according to formula (1):
Sn(%) = mV. X 10° s
Where: m,-the amount of tin found from the working curve, ug; total volume of test solution, mL;
volume of test solution taken, mL;
mass of the sample, 8.
The result is expressed to two decimal places. If the tin content is less than 0.10%, it is expressed to two decimal places; if it 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
Tin content
0. 000 50~ 0. 001 5
≥0. 001 5~0. 003 0
≥0. 003 0~ 0. 006 0
>0. 006 0~ 0. 025
>0. 025~0. 080
>0. 080~0. 20
≥0. 20~0.60
>0. 60~1. 00
8 Scope
Method 2 Determination of tin content by potassium iodate titration
This standard specifies the determination method of tin content in lead and lead alloys. This standard is applicable to the determination of tin content in lead and lead alloys. Determination range: >1.00%～15.50%, 9 Method summary
The sample is dissolved in sulfuric acid, and the tetravalent tin is reduced to divalent tin in the hydrochloric acid solution with aluminum sheet. With starch as the indicator, titrate with potassium iodate standard titration solution.
10 Reagents
10.1 Aluminum sheet.
10. 2 Sulfuric acid (pl. 84 g/ml.)
10.3 Hydrochloric acid (p1.19 g/mL).
10.4 Saturated sodium bicarbonate solution.
GB/T 4103.12000
10.5 Potassium iodate standard titration solution [c (1/6K10,) = 0.033mol/L]. 10.5.1 Preparation
Weigh 3.567g potassium iodate (superior purity) into about 200ml of water containing 2g sodium hydroxide and 10g potassium iodide, wait for dissolution, dilute with water to 3000ml.
10.5.2 Calibration
Weigh 0.0500g pure tin (>99.95%) into a 500mL conical flask, and proceed as per 12.3.2 to 12.3.4. Perform the self-test with the calibration.
Calculate the actual concentration of potassium iodate standard titration solution according to formula (2): m
C (V, -V)× 0. 059 34
Actual concentration of potassium iodate standard titration solution, mol/L; formula. -
V. Volume of potassium iodate standard titration solution consumed by the test solution during calibration, mL; V, Volume of potassium iodate standard titration solution consumed by the blank test solution during calibration, mL; m
0. 059 34
Mass of tin +;
Mass of tin equivalent to 1.00mL of potassium iodate standard titration solution [e(1/6KI0)=1.00mol/1.], g/mol. Take 3 portions for calibration. The range of the volume of potassium iodate standard titration solution consumed for calibration should not exceed 0.10ml. Take the average value: otherwise, recalibrate.
10.6 Starch solution: Weigh 1.0g soluble starch into a 200ml beaker, add a little water and stir well, then pour it into 100ml boiling water. Boil and cool.
11 Apparatus
Tin reduction kit, see Figure 1.
1-Tin solution; 2-Conical flask; 3 Rubber tube; 4 Glass tube; 5-Saturated sodium bicarbonate solution Figure 1
Schematic diagram of tin reduction kit
12 Analysis steps
12.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. Tin content %
≥1.00～~4.00
24.00 -~6.00
6.00~12.00
12.00~15.50
Carry out 2 independent determinations and take the average value. 12.2 Blank test
Carry out a blank test with the sample at the same time.
12.3 Determination
GB/T 4103.1 ---2000
12.3.1 Place the sample (12.1) in a 500mL conical flask. 12.3.2 Add 20mL sulfuric acid, heat and dissolve until sulfuric acid smoke appears, remove and cool. Sample pad
12.3.3 Add 100ml water, 70ml hydrochloric acid, 2.0g aluminum sheet, cover with Geiger funnel stopper filled with saturated sodium bicarbonate solution as shown in the diagram, heat and boil for several minutes, wait for the solution to become clear, cool to room temperature with rapid running water, and be sure to add saturated sodium bicarbonate solution at any time during the cooling process to isolate the air.
12.3.4 Remove Geiger funnel | Rapidly add 5mL starch solution to the conical flask, and titrate with potassium iodate standard titration solution until the solution turns light blue.
13 Expression of analysis results
Calculate the percentage of tin according to formula (3):
Sn(%) c(Va Vo) × 0. 059 34 m
W:--the actual concentration of potassium iodate standard titration solution, mol/.X100
-the volume of potassium iodate standard titration solution consumed in the titration of the test solution during the determination, mL; V:--the volume of potassium iodate standard titration solution consumed in the titration of the empty test solution during the determination, mI. .
The mass of the sample.g
.05934 and 1.00mL potassium iodate standard dripping cage solution c (1/6K10) = 1.00mol/. The mass of tin equivalent to %mo] The result is expressed to the decimal place
14 Allowable difference
The difference in the analysis results between laboratories should not be too large. Table of allowable differences
Kick the bird world
>1. 00~5. 00
2 5. 00 ~~ 12. 00
12.00~15.50
Allowable0010% is expressed to five decimal places. 7 Allowable Difference
The difference between the analysis results of laboratories shall not be greater than the allowable difference listed in Table 2. Table 2
Tin Content
0. 000 50~ 0. 001 5
≥0. 001 5~0. 003 0
≥0. 003 0~ 0. 006 0
>0. 006 0~ 0. 025
>0. 025~0. 080
>0. 080~0. 20
≥0. 20~0.60
>0. 60~1. 00
8 Scope
Method 2 Determination of tin content by potassium iodate titration
This standard specifies the determination method of tin content in lead and lead alloys. This standard is applicable to the determination of tin content in lead and lead alloys. Determination range: >1.00%～15.50%, 9 Method summary
The sample is dissolved in sulfuric acid, and the tetravalent tin is reduced to divalent tin in the hydrochloric acid solution with aluminum sheet. With starch as the indicator, titrate with potassium iodate standard titration solution.
10 Reagents
10.1 Aluminum sheet.
10. 2 Sulfuric acid (pl. 84 g/ml.)
10.3 Hydrochloric acid (p1.19 g/mL).
10.4 Saturated sodium bicarbonate solution.
GB/T 4103.12000
10.5 Potassium iodate standard titration solution [c (1/6K10,) = 0.033mol/L]. 10.5.1 Preparation
Weigh 3.567g potassium iodate (superior purity) into about 200ml of water containing 2g sodium hydroxide and 10g potassium iodide, wait for dissolution, dilute with water to 3000ml.
10.5.2 Calibration
Weigh 0.0500g pure tin (>99.95%) into a 500mL conical flask, and proceed as per 12.3.2 to 12.3.4. Perform the self-test with the calibration.
Calculate the actual concentration of potassium iodate standard titration solution according to formula (2): m
C (V, -V)× 0. 059 34
Actual concentration of potassium iodate standard titration solution, mol/L; formula. -
V. Volume of potassium iodate standard titration solution consumed by the test solution during calibration, mL; V, Volume of potassium iodate standard titration solution consumed by the blank test solution during calibration, mL; m
0. 059 34
Mass of tin +;
Mass of tin equivalent to 1.00mL of potassium iodate standard titration solution [e(1/6KI0)=1.00mol/1.], g/mol. Take 3 portions for calibration. The range of the volume of potassium iodate standard titration solution consumed for calibration should not exceed 0.10ml. Take the average value: otherwise, recalibrate.
10.6 Starch solution: Weigh 1.0g soluble starch into a 200ml beaker, add a little water and stir well, then pour it into 100ml boiling water. Boil and cool.
11 Apparatus
Tin reduction kit, see Figure 1.
1-Tin solution; 2-Conical flask; 3 Rubber tube; 4 Glass tube; 5-Saturated sodium bicarbonate solution Figure 1
Schematic diagram of tin reduction kit
12 Analysis steps
12.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. Tin content %
≥1.00～~4.00
24.00 -~6.00
6.00~12.00
12.00~15.50
Carry out 2 independent determinations and take the average value. 12.2 Blank test
Carry out a blank test with the sample at the same time.
12.3 Determination
GB/T 4103.1 ---2000
12.3.1 Place the sample (12.1) in a 500mL conical flask. 12.3.2 Add 20mL sulfuric acid, heat and dissolve until sulfuric acid smoke appears, remove and cool. Sample pad
12.3.3 Add 100ml water, 70ml hydrochloric acid, 2.0g aluminum sheet, cover with Geiger funnel stopper filled with saturated sodium bicarbonate solution as shown in the diagram, heat and boil for several minutes, wait for the solution to become clear, cool to room temperature with rapid running water, and be sure to add saturated sodium bicarbonate solution at any time during the cooling process to isolate the air.
12.3.4 Remove Geiger funnel | Rapidly add 5mL starch solution to the conical flask, and titrate with potassium iodate standard titration solution until the solution turns light blue.
13 Expression of analysis results
Calculate the percentage of tin according to formula (3):
Sn(%) c(Va Vo) × 0. 059 34 m
W:--the actual concentration of potassium iodate standard titration solution, mol/.X100
-the volume of potassium iodate standard titration solution consumed in the titration of the test solution during the determination, mL; V:--the volume of potassium iodate standard titration solution consumed in the titration of the empty test solution during the determination, mI. .
The mass of the sample.g
.05934 and 1.00mL potassium iodate standard dripping cage solution c (1/6K10) = 1.00mol/. The mass of tin equivalent to %mo] The result is expressed to the decimal place
14 Allowable difference
The difference in the analysis results between laboratories should not be too large. Table of allowable differences
Kick the bird world
>1. 00~5. 00
2 5. 00 ~~ 12. 00
12.00~15.50
Allowable0010% is expressed to five decimal places. 7 Allowable Difference
The difference between the analysis results of laboratories shall not be greater than the allowable difference listed in Table 2. Table 2
Tin Content
0. 000 50~ 0. 001 5
≥0. 001 5~0. 003 0
≥0. 003 0~ 0. 006 0
>0. 006 0~ 0. 025
>0. 025~0. 080
>0. 080~0. 20
≥0. 20~0.60
>0. 60~1. 00
8 Scope
Method 2 Determination of tin content by potassium iodate titration
This standard specifies the determination method of tin content in lead and lead alloys. This standard is applicable to the determination of tin content in lead and lead alloys. Determination range: >1.00%～15.50%, 9 Method summary
The sample is dissolved in sulfuric acid, and the tetravalent tin is reduced to divalent tin in the hydrochloric acid solution with aluminum sheet. With starch as the indicator, titrate with potassium iodate standard titration solution.
10 Reagents
10.1 Aluminum sheet.
10. 2 Sulfuric acid (pl. 84 g/ml.)
10.3 Hydrochloric acid (p1.19 g/mL).
10.4 Saturated sodium bicarbonate solution.
GB/T 4103.12000
10.5 Potassium iodate standard titration solution [c (1/6K10,) = 0.033mol/L]. 10.5.1 Preparation
Weigh 3.567g potassium iodate (superior purity) into about 200ml of water containing 2g sodium hydroxide and 10g potassium iodide, wait for dissolution, dilute with water to 3000ml.
10.5.2 Calibration
Weigh 0.0500g pure tin (>99.95%) into a 500mL conical flask, and proceed as per 12.3.2 to 12.3.4. Perform the self-test with the calibration.
Calculate the actual concentration of potassium iodate standard titration solution according to formula (2): m
C (V, -V)× 0. 059 34
Actual concentration of potassium iodate standard titration solution, mol/L; formula. -
V. Volume of potassium iodate standard titration solution consumed by the test solution during calibration, mL; V, Volume of potassium iodate standard titration solution consumed by the blank test solution during calibration, mL; m
0. 059 34
Mass of tin +;
Mass of tin equivalent to 1.00mL of potassium iodate standard titration solution [e(1/6KI0)=1.00mol/1.], g/mol. Take 3 portions for calibration. The range of the volume of potassium iodate standard titration solution consumed for calibration should not exceed 0.10ml. Take the average value: otherwise, recalibrate.
10.6 Starch solution: Weigh 1.0g soluble starch into a 200ml beaker, add a little water and stir well, then pour it into 100ml boiling water. Boil and cool.
11 Apparatus
Tin reduction kit, see Figure 1.
1-Tin solution; 2-Conical flask; 3 Rubber tube; 4 Glass tube; 5-Saturated sodium bicarbonate solution Figure 1
Schematic diagram of tin reduction kit
12 Analysis steps
12.1 Test materials
Weigh the sample according to Table 3, accurate to 0.0001g. Tin content %
≥1.00～~4.00
24.00 -~6.00
6.00~12.00
12.00~15.50
Carry out 2 independent determinations and take the average value. 12.2 Blank test
Carry out a blank test with the sample at the same time.
12.3 Determination
GB/T 4103.1 ---2000
12.3.1 Place the sample (12.1) in a 500mL conical flask. 12.3.2 Add 20mL sulfuric acid, heat and dissolve until sulfuric acid smoke appears, remove and cool. Sample pad
12.3.3 Add 100ml water, 70ml hydrochloric acid, 2.0g aluminum sheet, cover with Geiger funnel stopper filled with saturated sodium bicarbonate solution as shown in the diagram, heat and boil for several minutes, wait for the solution to become clear, cool to room temperature with rapid running water, and be sure to add saturated sodium bicarbonate solution at any time during the cooling process to isolate the air.
12.3.4 Remove Geiger funnel | Rapidly add 5mL starch solution to the conical flask, and titrate with potassium iodate standard titration solution until the solution turns light blue.
13 Expression of analysis results
Calculate the percentage of tin according to formula (3):
Sn(%) c(Va Vo) × 0. 059 34 m
W:--the actual concentration of potassium iodate standard titration solution, mol/.X100
-the volume of potassium iodate standard titration solution consumed in the titration of the test solution during the determination, mL; V:--the volume of potassium iodate standard titration solution consumed in the titration of the empty test solution during the determination, mI. .
The mass of the sample.g
.05934 and 1.00mL potassium iodate standard dripping cage solution c (1/6K10) = 1.00mol/. The mass of tin equivalent to %mo] The result is expressed to the decimal place
14 Allowable difference
The difference in the analysis results between laboratories should not be too large. Table of allowable differences
Kick the bird world
>1. 00~5. 00
2 5. 00 ~~ 12. 00
12.00~15.50
AllowableIn boiling water. Boil and cool.
11 Apparatus
Tin reduction device, see Figure 1.
1-Tin solution; 2-Conical flask; 3 Rubber tube; 4 Glass tube; 5-Saturated sodium bicarbonate solution Figure 1
Schematic diagram of tin reduction device
12 Analysis steps
12.1 Sample
Weigh the sample according to Table 3, accurate to 0.0001g. Tin content%
≥1. 00～~4. 00
24. 00 -~6. 00
6. 00~12. 00
12. 00~15. 50
Carry out 2 independent determinations and take the average value. 12.2 Blank test
Carry out a blank test with the sample.
12.3 Determination
GB/T 4103. 1 ---2000
12.3.1 Place the sample (12.1) in a 500mL conical flask. 12.3.2 Add 20mL sulfuric acid, heat and dissolve until sulfuric acid smoke appears, remove and cool. Sample pad
12.3.3 Add 100mL water, 70mL hydrochloric acid, and 2.0g aluminum sheet, cover with a Geiger funnel stopper filled with saturated sodium bicarbonate solution as shown in the schematic diagram, heat and boil for several minutes, wait for the solution to become clear, and cool it to room temperature with rapid running water. During the cooling process, be sure to add saturated sodium bicarbonate solution at any time to isolate the air.
12.3.4 Remove the Geiger funnel. Rapidly add 5mL starch solution to the conical flask, and titrate with potassium iodate standard titration solution until the solution turns light blue.
13 Expression of analysis results
Calculate the percentage of tin according to formula (3):
Sn(%) c(Va Vo) × 0. 059 34 m
W:--the actual concentration of potassium iodate standard titration solution, mol/.X100
-the volume of potassium iodate standard titration solution consumed in the titration of the test solution during the determination, mL; V:--the volume of potassium iodate standard titration solution consumed in the titration of the empty test solution during the determination, mI. .
The mass of the sample.g
.05934 and 1.00mL potassium iodate standard dripping cage solution c (1/6K10) = 1.00mol/. The mass of tin equivalent to %mo] The result is expressed to the decimal place
14 Allowable difference
The difference in the analysis results between laboratories should not be too large. Table of allowable differences
Kick the bird world
>1. 00~5. 00
2 5. 00 ~~ 12. 00bZxz.net
12.00~15.50
AllowableIn boiling water. Boil and cool.
11 Apparatus
Tin reduction device, see Figure 1.
1-Tin solution; 2-Conical flask; 3 Rubber tube; 4 Glass tube; 5-Saturated sodium bicarbonate solution Figure 1
Schematic diagram of tin reduction device
12 Analysis steps
12.1 Sample
Weigh the sample according to Table 3, accurate to 0.0001g. Tin content%
≥1. 00～~4. 00
24. 00 -~6. 00
6. 00~12. 00
12. 00~15. 50
Carry out 2 independent determinations and take the average value. 12.2 Blank test
Carry out a blank test with the sample.
12.3 Determination
GB/T 4103. 1 ---2000
12.3.1 Place the sample (12.1) in a 500mL conical flask. 12.3.2 Add 20mL sulfuric acid, heat and dissolve until sulfuric acid smoke appears, remove and cool. Sample pad
12.3.3 Add 100mL water, 70mL hydrochloric acid, and 2.0g aluminum sheet, cover with a Geiger funnel stopper filled with saturated sodium bicarbonate solution as shown in the schematic diagram, heat and boil for several minutes, wait for the solution to become clear, and cool it to room temperature with rapid running water. During the cooling process, be sure to add saturated sodium bicarbonate solution at any time to isolate the air.
12.3.4 Remove the Geiger funnel. Rapidly add 5mL starch solution to the conical flask, and titrate with potassium iodate standard titration solution until the solution turns light blue.
13 Expression of analysis results
Calculate the percentage of tin according to formula (3):
Sn(%) c(Va Vo) × 0. 059 34 m
W:--the actual concentration of potassium iodate standard titration solution, mol/.X100
-the volume of potassium iodate standard titration solution consumed in the titration of the test solution during the determination, mL; V:--the volume of potassium iodate standard titration solution consumed in the titration of the empty test solution during the determination, mI. .
The mass of the sample.g
.05934 and 1.00mL potassium iodate standard dripping cage solution c (1/6K10) = 1.00mol/. The mass of tin equivalent to %mo] The result is expressed to the decimal place
14 Allowable difference
The difference in the analysis results between laboratories should not be too large. Table of allowable differences
Kick the bird world
>1. 00~5. 00
2 5. 00 ~~ 12. 00
12.00~15.50
Allowable
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