This standard specifies the determination of nickel content by dimethylglyoxime photometric method. This standard is applicable to the determination of nickel content in phosphor copper brazing materials, with a determination range of 0.20% to 0.80%. JB/T 7520.6-1994 Chemical analysis method for phosphor copper brazing materials Determination of nickel content by dimethylglyoxime photometric method JB/T7520.6-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Chemical Analysis Method of Phosphor Copper Brazing Filler
Determination of Nickel by Diacetyl Spectrophotometry
Subject Content and Scope of Application
This standard specifies the determination of nickel content by diacetyl spectrophotometry. This standard is applicable to the determination of nickel content in phosphor copper brazing filler, with a determination range of 0.20%~0.80%. 2 Method Summary
JB/T 7520.6—94
After the sample is dissolved in hydrochloric acid and hydrogen peroxide, potassium iodide is added to separate a large amount of copper, and citrate is used to mask the tin and other dry elements. In the presence of an oxidant, diacetyl is added to form a red complex with nickel ions, and the photometric determination is performed. 3 Reagents
3.1 Hydrochloric acid (pl.19 g/mL).
3.2 Hydrogen peroxide (commercially available 30%).
3.3 Potassium iodide solution (30%).
3.4 ​​Ammonium citrate solution (50%).
3.5 Diacetyl solution (0.1%): Weigh 1g diacetyl and dissolve it in 1000mL nitrogen water (1+1). 3.6 Nickel standard solution: Weigh 0.1000g of metallic nickel (purity of 99.99% or more) and place it in a 100mL conical flask, add 5mL nitric acid (1+1), heat to dissolve, boil to remove nitrogen oxides, cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and mix well. This solution contains 0.10 mg nickel in 1mL.
3.7 Metallic copper (purity of 99.99% or more). 4 Analysis steps
4.1 Sample quantity
Weigh 0.1000g of sample.
4.2 Blank test
Weigh the same amount of copper metal (2.7) as the sample as a blank. 4.3 Determination
4.3.1 Place the sample (4.1) in a 100mL dual-purpose bottle, add 3mL of hydrochloric acid (3.1) and 2mL of hydrogen peroxide (3.2). After the sample is dissolved, boil for 30 minutes to decompose the excess hydrogen peroxide, cool, add water to about 60mL, add 10mL of potassium sulfonate solution (3.3), dilute to the scale with water, and mix. Dry filter with medium-speed filter paper. 4.3.2 Pipette 10.00mL of the solution into a 50mL volumetric flask, add 5mL of ammonium citrate solution (3.4) and 10mL of water, mix, add 10mL of diacetyl solution (3.5), dilute to the scale with water, and mix. Let stand for 15 minutes. 4.3.3 Pipette part of the solution into a 3 cm colorimetric solution and use the reagent blank solution (Section 4.2) as the reference solution. Measure its absorbance at a wavelength of 530 nm on a spectrophotometer. Find the corresponding nickel content from the working curve. 4.4 Drawing of working curve
Approved by the Ministry of Machinery Industry of the People's Republic of China on 1994-12-09, Sold on 1995-10-01
JB/T 7520.6-94
Weigh 0.1000g of copper metal in six portions, place them in 100mL dual-purpose bottles, add 3mL of hydrochloric acid (3.1) and 2mL of supernatant (3.2) to dissolve the sample, boil slightly for 30min, cool, add 0, 1.00, 3.00, 5.00, 7.009.00mL of standard solution (3.6) in sequence, add water to about 60mL, add 10mL of potassium iodide solution (3.3), dilute to scale with water, and mix. Dry filter with medium-speed filter paper. The following is carried out according to 4.3.2 and 4.3.3. Take 0mL as the reference solution and measure the absorbance. With nickel content as the horizontal axis and absorbance as the vertical axis, draw the working curve.
5 Calculation of analysis results
Calculate the percentage of nickel content according to the following formula:
_mV. ×10#
Ni(%)=
The amount found from the working curve, mg,
Where: m—
V. —Total volume of the sample solution, mL
Vi--Volume of the sample solution taken, mL,
mWeighing amount, g.
6 Allowable difference
The difference in the analysis results should not be greater than the allowable difference listed in Table 1. Table 1
0.20~0.80www.bzxz.net
Additional notes:
This standard was proposed by Harbin Welding Research Institute of the Ministry of Machinery Industry. This standard was drafted by Harbin Welding Research Institute. The main drafters of this standard are Bai Yun, Lin Kegong and Ye Xiuzang. 328
Allowed difference
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