This standard specifies the determination method of cerium content in silver alloys. This standard is applicable to the determination of cerium content in AgCe0.5 alloys. Determination range: 0.3% to 0.7%. GB/T 15072.13-1994 Chemical analysis methods for precious metals and their alloys Determination of cerium content in silver alloys GB/T15072.13-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis methods for precious metals and their alloys
Determination of cerium content in silver alloy
Silver alloy Determination of cerium content1 Subject content and scope of application
This standard specifies the method for determining the cerium content in silver alloy. GB/T 15072.13 ---94
This standard is applicable to the determination of cerium content in AgCe0.5 alloy. Determination range: 0.3%~0.7%. 2 Reference standardswwW.bzxz.Net
GB1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis methods GB1467 General principles and general provisions for chemical analysis methods for metallurgical products GB7729 General principles for spectrophotometric methods for chemical analysis of metallurgical products 3 Summary of methods
The sample is dissolved in nitric acid, and in the presence of NazEDTA in a 0.1 mol/L nitric acid medium, (substance) forms a blue complex with occasional dapoxets, and its absorbance is measured at a wavelength of 680 nm on a spectrophotometer. 4 Reagents
The reagents and water used in this standard shall not contain chlorine ions. 4.1 Nitric acid (boil to remove all nitrogen oxides, 1+1). 4.2 Nitric acid (1+1).
4.3 Disodium dapoxets (NaEDTA·2H,O) solution (0.02 mol/L), 4.4 Azofluorinated dapoxets solution (0.2 g/L). 4.5 Cadmium standard stock solution: weigh 0.6142g of cerium oxide (Ce0≥99.9%) and place it in a 300ml beaker, add 401ml of nitric acid (p1.42g/ml) and hydrogen peroxide (30%), heat to dissolve, add hydrogen peroxide several times until the cerium oxide is completely dissolved, and boil slightly until the hydrogen peroxide is completely decomposed. Cool, transfer to a 500ml volumetric flask, dilute to scale with water, and mix. This solution contains 1mg cerium per ml. 4.6 Cerium standard solution: transfer 2.50mL of cerium standard stock solution to a 50ml volumetric flask, dilute to scale with water, and mix. This solution contains 50μg per ml. Prepare on the same day.
5 Instruments
Spectrophotometer.
6 Samples
The samples are processed into crumbs, and finally degreased with acetone, washed, dried, and mixed. Approved by the State Administration of Technical Supervision on May 11, 1994 106
1994-1201 implementation
7 Analysis steps
7.1 Test sample
GB/T 15072.13---94
Weigh about 0.1g of the sample to an accuracy of 0.0001g. Perform two independent determinations and take the average value. 7.2 Blank test
Perform a blank test with the sample.
7.3 Determination
7.3.1 Place the sample (7.1) in a 50ml beaker, add 3ml nitric acid (4.1), cover with surface III and heat until completely dissolved, remove, rinse surface III and the beaker wall with water, evaporate until almost dry, dissolve the residue with water and transfer to a 100ml volumetric flask, dilute to scale with water, mix with a spoon, transfer 5.00ml of the test solution to a 50ml volumetric flask.
7.3.2 Add 2.5ml nitric acid (4.2) and dilute to about 35ml with water, add 2.00ml Na2EDTA solution and mix well. Add 7.00ml azophosphine oxide III solution, dilute to scale with water and mix well. 7.3.3 Transfer part of the solution into a 2cm absorption III, use the blank sample as a reference, and measure its absorbance at a wavelength of 680nm on a spectrophotometer. Obtain the absorbance from the working curve. 7.4 Drawing of working curve
7.4.1 Transfer 0.0.10, 0.20.0.40, 0.60, 0.80, 1.00mL of cerium standard solution to a set of 50mL volumetric flasks. Proceed as follows with 7.2.2.
7.4.2 Transfer part of the solution to 2cm absorbent tube, use reagent blank as reference, and measure its absorbance at 680nm wavelength on a spectrophotometer.
7.4.3 Draw working curve with cerium content as horizontal axis and absorbance as vertical axis. 8 Expression of analysis results
Calculate the percentage of cerium by the following formula:
m × V.× 10-6
Ce(%) -
Where: m--cerium content found on the working curve, ugV. .Total volume of test solution, ml.;
V.---Volume of test solution taken, mL;
m.Mass of test material, g.
The result should be expressed to two decimal places.
9Allowable difference
The difference in analysis results between laboratories should not exceed 0.06%. Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Kunming Precious Metals Research Institute. The main drafter of this standard was Wu Ruilin.
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