GB/T 3260.10-2000 Chemical analysis method for tin - Determination of sulfur content
Some standard content:
GB/T3260.10--2000
This standard is a new confirmation of GB/T3260.10--2000--1988 "Chemical analysis method of tin - determination of sulfur by distillation oscillographic polarography" and makes editorial changes.
This standard complies with:
GB/T1.1-1993 Standardization work guidelines Unit 1: Rules for drafting and expressing standards Part 1: Basic provisions for standard writing
GB/T1.4-1988 Standardization work guidelines Rules for the writing of chemical analysis methods GB/T1467-1978 General principles and general provisions for chemical analysis methods for metallurgical products GB/T17433--1998 Basic terminology for chemical analysis methods for metallurgical products This standard will replace GB/T3260.10--1988 from the date of implementation. This standard is proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard was drafted by Yunnan Tin Company and Liuzhou Huaxi Group Co., Ltd. This standard was drafted by Beijing Nonferrous Metals Research Institute. The main drafters of this standard are Lin Zhongpeng, Jin Jingru, Yu Shurong and Zhou Xiankang. 90
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of tinDeternination of sulphur content
Methods for chemical analysis of tinDeternination of sulphur content This standard specifies the method for determination of sulphur content in tin. This standard is applicable to the determination of sulphur content in tin, with a determination range of 0.00010% to 0.020%2 Summary of the method
GB/T 3260. 10---2000
Replaces GB/T 3260.10—1988
Use hydroiodic acid-hydrochloric acid-hypophosphorous acid as reducing agent and solvent for tin, heat and dissolve the sample in a distillation flask, and carry out the sulfur star hydrogen sulfide through nitrogen, absorb it in 0.5mol/L sodium hydroxide solution, scan at -0.6～1.1V on the oscilloscope polarograph, record the peak value, and the sample contains 10mg lead, 6mg antimony, 1mg arsenic, bismuth, iron and copper, which do not interfere with the determination. 3 Reagents
The water used in this method is sub-boiling distilled or deionized water. 3.1 Nitrogen: Nitrogen content>99.7%.
3.2 Copper solution: Weigh 2.66g copper ferride (CuCl2·2H,0) in 100mL hydrochloric acid (1+1, high-grade pure) and mix with a spoon. This solution contains 100mg copper in 1ml.
3.3 Platinum solution: Weigh 26.83g of chloroplatinic acid (H2PtCl.·6HO) and dissolve it in 100mL of hydrochloric acid (1+1, high-grade pure), and mix. 1ml of this solution contains 10 mg of platinum.
3.4 Reducing agent
3.4.1 Take 300mL of hydroiodic acid (pl.50g/ml, high-grade pure), 200mL of hydrochloric acid (pl.19g/mL, high-grade pure), 150ml of hypophosphorous acid (50%, high-grade pure) and 50ml of water, place them in a 1000mL reflux distillation flask, heat and reflux distillation for 7-8h, until the test is positive for sulfur-free. Before use, add 0.5ml of copper solution (3.2) and 0.5mL of platinum solution (3.3) to every 100ml of reducing agent. Distill at 1000mL flow rate until sulfur is detected.
3.4.2 Take 400mL of hydroiodic acid (p1.5g/mL, high-grade pure), 200ml of hydrochloric acid (pl.19g/ml, high-grade pure) and 100g of sodium hypophosphite, put them in a 1000mL reflux distillation flask, mix well, add copper solution (3.2) and platinum solution (3.3), and the purification method is the same as 3.4.1. 3.5 Absorption liquid: c(NaOH)=0.5mol/L sodium hydroxide (high-grade pure) solution. Store in a polyethylene bottle. 3.6 Polyvinyl alcohol solution (0.5%).
3.7 Potassium permanganate-mercuric chloride mixed solution: Weigh 3g of potassium permanganate and dissolve it in a mixed solution of 75mL of saturated mercuric difluoride and 75mL of water. Transfer it to a gas washing bottle.
3.8 Molybdenum chloride solution (5%): Weigh 7.5g of molybdenum chloride (BaCl, ·2H2O) and dissolve it in 150ml of water, then transfer it to a gas washing bottle. 3.9 Sulfur standard stock solution: Weigh 4.4375g of anhydrous sodium sulfate (superior grade pure) previously dried at 120°C and dissolve it in a small amount of water, then transfer it to a 1000mL volumetric flask, dilute it to the mark with water, and mix it. This solution contains 1mg of sulfur per ml. 3.10 Sulfur standard solution: Transfer 20.00mL of sulfur standard stock solution to a 1000ml volumetric flask, dilute it to the mark with water, and mix it. This solution contains 20μg of sulfur per ml. Approved by the State Administration of Quality and Technical Supervision on 2000-08-28 and implemented on 200012-01
GB/T 3260. 10--2000
3.11 Sulfur standard condensate solution: Pipette 5.00 mL of sulfur standard stock solution into a 1000 mL volumetric flask, dilute to the mark with water, and mix. 1 mL of this solution contains 5 μg of sulfur.
4 Instruments
Reduction distillation apparatus, see Figure 1:
gio-12
$30~34
1- Nitrogen bottle; 2- Pressure gauge; 3- Potassium permanganate mercuric chloride mixed solution washing bottle; 4- Barium chloride solution washing bottle; 5- Buffer bottle, 6- Ground mouth stopper, 7· Reducing agent bottle; 8· -- Active cold; 9 Distillation bottle 1: 10- Condenser; 11- Distillation bottle 112- Absorption tube, 13- Adjustable heater Figure 1 Reduction distillation apparatus diagram
5 Analysis steps
5.1 Test material
Weigh the sample according to Table 1. Accurate to 0.0001g. Table 1
Sulfur content, %
0. 000 10~~ 0. 000 50
: 0. 000 50~ 0. 001 0
0. 001 0-~0. 005 0
0. 005 0~0. 010
7*0. 010~ 0. 020
Carry out 2 independent determinations and take the average value. 5.2 Blank test
Carry out a blank test with the sample.
5.3 Determination
Sample amount·g
Absorbent, ml.
5.3.1 Place the sample (5.1) in a distillation flask 1, add 8~~10ml of reducing agent (3.4.1) to the distillation flask 1, connect the various parts of the reduction distillation 92
GB/T3260.10--2000
device, and insert the outlet tube into the absorption tube containing the absorption liquid. 5.3.2 Heat the distillation flask 1 to make the reducing agent (3.4.1) boil and keep it slightly boiling (the reducing agent in this flask can be used for several days and does not need to be replaced every day) 5.3.3 Pass nitrogen at a rate of about 25mL/min. Under nitrogen flow, add 15ml of reducing agent (3.4.1). If hypophosphorous acid is not available during preparation, the reducing agent (3.4.2) can be used instead in the distillation flask, and the sample (5.1) is heated to dissolve. Note: When weighing 1g of sample, 20mL of reducing agent (3.4.1) is required. The sample (5.1) should be dissolved in about 10 minutes. If the sample is dissolved slowly, the amount of copper solution and platinum solution can be appropriately increased in the reducing agent (3.4.1). 5.3.4 After the sample (5.1) is dissolved, keep it slightly boiling and continue to pass nitrogen at a rate of 50~100ml./min for about 10 minutes. From the addition of reducing agent (3.4.1) to the completion of absorption, a total of no less than 20 minutes. 5.3.5 Remove the absorption tube, add 1 drop (about 0.05mL) of polyvinyl alcohol solution for every 5mL of absorption liquid, and mix well. Note: The amount of polyvinyl alcohol has a great influence on the waveform, and must be strictly controlled in the sample analysis and standard solution preparation. 5.3.6 Transfer part of the absorption liquid to the electrolysis cup, and scan on the oscillographic polarograph (using electrodes). 0.61.1V, 2 peaks.
5.3.7 Transfer 3 portions of sulfur standard solution (3.10 or 3.11) with a sulfur content similar to that of the sample, and proceed as follows 5.3.1 to 5.3.6. The relative error of the peak range of the 3 portions of sulfur standard solution is not more than 4%, and the average value is taken as the peak value of the sulfur standard solution. 6 Expression of analysis results
Calculate the percentage of sulfur according to formula (1):
S(%) =- C: Ve(/ -10) × 10-6ms·I.
Concentration of sulfur standard solution, pg/ml;
VVolume of sulfur standard solution, mL
I, peak current of sample, pA;
I, peak current of blank test solution, μA; I-peak current of standard solution μA
mMass of sample,.
The result is expressed to three decimal places. If the sulfur content is less than 0.010%, it is expressed to four decimal places; less than 0.0010%. Express to five decimal places.
7Tolerance
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Sulfur contentwww.bzxz.net
0. 000 10~ 0. 000 30
≥0. 000 30-~ 0. 000 60
7-0. 000 60~ 0. 001 0
=0, 001 0 ~ 0. 003 0
≥0, 003 0~ 0. 005 0
二= 0. 005 9~0. 010
0. 010~- 0. 020
allowance difference
0. 000 30
0, 001
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