GOST 1429.7-77
GOST 1429.7−77 Solders tin-lead. Method for the determination of Nickel (with Amendments No. 1, 2)
GOST 1429.7−77*
Group B59
STATE STANDARD OF THE USSR
SOLDERS TIN-LEAD
Method for the determination of Nickel
Tin-lead solders.
Method for the determination of nickel*
AXTU 1709**
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* The name of the standard. Changed the wording, Rev. N 2.
** Added, Rev. N 2.
Date of introduction 1978−01−01
The decision of the State standards Committee of the USSR Council of Ministers dated 11 April 1977, N 886 the period of validity set with 01.01.78
PROVEN in 1982 by the Resolution of Gosstandart from
_____________
** Expiration removed Protocol MGS (IUS N 2, 1993). — Note the manufacturer’s database.
REPLACE GOST 1429.7−69
* REPRINT March 1983 with the Change in N 1, approved in January 1983; Post. N 325 from
The Change N 2 approved and put into effect with
Change No. 2 made by the manufacturer of the database in the text IUS N 11, 1987
This standard establishes photocolorimetric method of determining the mass fraction of Nickel in tin-lead solder (with a mass fraction of Nickel from 0.0005 to 0.08%).
The method is based on dissolving the sample in a mixture bromatological acid and bromine, separation of tin and antimony in the form of bromides in the presence of perchloric acid, separation of copper on the metal lead, the formation of complex compounds of Nickel with dimethylglyoxime and measuring the optical density of the resulting solution.
(Changed edition, Rev. N 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 1429.0−77.
2. APPARATUS, REAGENTS AND SOLUTIONS
Photoelectrocolorimeter or spectrophotometer.
Nitric acid GOST 4461−77 and diluted 1:1.
Bromatologia acid according to GOST 2062−77.
Bromine according to GOST 4109−79.
The mixture for dissolution is prepared as follows: to 90 cmbromatological acid, carefully add 10 cm
of bromine, and mix.
Perchloric acid, a solution with a mass fraction of 57%.
Lead, granulated.
Citric acid according to GOST 3652−69 (ST SEV 394−76), a solution with a mass fraction of 30%; prepared as follows: 300 g of citric acid are placed in a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water, mix.
Ethyl alcohol.
Bromine water, saturated solution.
Dimethylglyoxime according to GOST 5828−77, alcohol solution with a mass fraction of 1%.
Ammonia according to GOST 3760−79 diluted 1:1.
Nickel stamps BUT according to the GOST 849−70*.
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* Valid GOST 849−97. — Note the manufacturer’s database.
Standard solutions of Nickel.
Solution a (basic); prepare as follows: 0.2 g of Nickel were placed in a glass with a capacity of 100 cmand dissolved in 20 cm
of nitric acid, diluted 1:1, under low heat. Remove the oxides of nitrogen, cooled, transferred into a measuring flask with volume capacity of 1000 cm
, adjusted to the mark with water, mix. 1 cm
of the solution contains 0.0002 g of Nickel.
Solution B is prepared as follows: 10 cmof solution A is placed in a volumetric flask with a capacity of 100 cm
, adjusted to the mark with water, mix. 1 cm
of solution B contains 0,00002 g of Nickel.
Solution B is prepared before use.
(Changed edition, Rev. N 2).
3. ANALYSIS
3.1. A portion of the solder mass 0.5 g is placed in a low glass with a capacity of 250 cm, flow 20 cm
of the mixture for dissolution, dissolve at a moderate heat, closing the glass of the watch glass. After complete dissolution of the sample add 15 cm
of perchloric acid and evaporated with moderate heat until copious white fumes of perchloric acid. Repeat the evaporation with 10 cm
of the mixture to release vapors of perchloric acid two more times.
After cooling, add 1 cmof concentrated nitric acid in two doses (0.5 cm
) for the decomposition of bromine, heated to remove bromine and vapors escaping perchloric acid. When the evaporation is needed to avoid large losses of perchloric acid.
Upon receipt of a clear solution* perchloric acid is evaporated to a volume of 2 cm. Cooled, the contents of the Cup diluted with water to a volume of 40 cm
. To the solution was added 5 g of granulated lead, close a glass watch glass and boil moderately for 15 min. Then added 1 g of lead and boil for another 10 min. If the surface is newly added lead is clean and not painted with the separated copper recovery is complete. The solution is poured over the lead and lead is washed by decantation. If the solution is turbid, it is filtered through a dense filter and washed three to four times with water.
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* If the solution is cloudy, you need to add 5 cmof the mixture bromatological acid with bromine and repeat the evaporation.
The solution was transferred to volumetric flask with a capacity of 100 cm, the resulting solution is diluted with water to a volume of 50 cm
(if necessary), poured 10 cm
of the citric acid solution, 5 cm
of bromine water and a sufficient amount of ammonia, diluted 1:1, for bleaching the color of the bromine and 3 cm
in excess. After each addition of the reagent the solution was stirred. Cooled to room temperature, add 3 cm
of a solution dimethylglyoxime, adjusted to the mark with water, mix. Add bromine water, ammonia, and dimethylglyoxime necessary without gaps in time. In 10±2 minutes, measure the optical density of the solution on a photoelectrocolorimeter with a green filter (wavelength 580 nm) in a cuvette with a layer thickness of 2 cm.
As a solution the comparison used the zero solution.
At the same time through the analysis of spend control experience. The Nickel content is found by the calibration schedule, taking into account allowances for
reagents.
3.2. Construction of calibration curve
In glasses with a capacity of 100 cmeach placed 0; 0,5; 1,0; 2,0; 4,0; 6,0; 10,0; 15,0 20.0 cm
standard solution B, add 5 cm
of perchloric acid, evaporated with moderate heat to a volume of 2 cm
and further analysis is carried out as specified in clause 3.1.
On the found values of optical densities of solutions and their respective Nickel concentrations to build calibration curve.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of Nickel () in percent is calculated by the formula
where is the mass of Nickel was found in the calibration schedule g;
— the weight of the portion,
(Changed edition, Rev. N 2).
4.2. Allowable absolute differences the results of the analysis at a confidence level of 0.95, should not exceed the values given in the table.
| Mass fraction of Nickel, % | Allowable absolute differences, % |
| From 0.0005 to 0.001 |
0,0003 |
| SV. Of 0.001 «to 0.002 |
About 0.0006 |
| «To 0.002» 0.004 s |
0,001 |
| «Of 0.004» to 0.01 |
0,002 |
| «0,01» 0,04 |
0,005 |
| «Of 0.04» to 0.08 |
0,01 |
(Changed edition, Rev. N 1, 2).
