GOST 1429.3-77
GOST 1429.3−77 Solders tin-lead. Method for determination of iron content (with Amendments No. 1, 2)
GOST 1429.3−77*
Group B59
STATE STANDARD OF THE USSR
SOLDERS TIN-LEAD
Method for determination of iron
Tin-lead solders.
Method for the determination of iron*
AXTU 1709**
_________________
* The name of the standard. Changed the wording, Rev. N 2.
** Code standard. Introduced later, 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 1429.3−69
* REPRINT March 1983 with the Change in N 1, approved in January 1983; Post. N 324 from
The Change N 2 approved and put into effect by the Decree of the USSR State Committee for standards from
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 iron in tin-lead solder (with a mass fraction of iron from 0.001 to 0.02%).
The method is based on dissolving the sample in a mixture bromatological acid and bromine, separation of tin and antimony, the Stripping in the form of bromides, the formation of complex compounds of iron with ortofenantrolinom and measuring the optical density of the colored complex. Large amount of copper is separated in the form of metal when you restore the lead.
(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.
Perchloric acid, a solution with a mass fraction of 57%.
Bromine according to GOST 4109−79.
Mix to dissolve; prepared as follows: to 90 cmbromatological acid, carefully add 10 cm
of bromine, and mix.
Hydroxylamine hydrochloric acid according to GOST 5456−79, freshly prepared mortar, prepared as follows: 10 g of hydroxylamine hydrochloride dissolved in a small amount of water and adjusted with water to a volume of 1000 cm.
Orthophenanthroline solution; prepared as follows: 1.5 g orthophenanthroline dissolved in water and adjusted with water to a volume of 1000 cm. The solution is stored in container made of dark glass.
Acetic acid GOST 61−75.
Crystalline sodium acetate according to GOST 199−78.
Buffer solution; prepared as follows: 272 g sodium acetate and dissolve in 500 cmof water, add 240 cm
of acetic acid, filtered and adjusted with water to a volume of 1000 cm
.
The reaction mixture, freshly prepared; prepared as follows: one portion of a solution of hydroxylamine hydrochloric acid is mixed with one fraction of the solution orthophenanthroline and three proportions of buffer solution.
Lead granular brand WITH GOST 3778−77*.
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* Valid GOST 3778−98. — Note the manufacturer’s database.
Iron OS.CH., received a carbonyl method.
Standard solutions of iron.
Solution a (basic); prepared as follows: 0.1 g of iron is placed in a beaker with a capacity of 100 cmand dissolved in 10 cm
of nitric acid, diluted 1:1, the solution was boiled to remove 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 0.0001 g of iron.
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 0,00001 g of iron.
Solution B is prepared on the day of application.
Ammonia according to GOST 3760−79 diluted 1:1.
Indicator paper, universal.
(Changed edition, Rev. N 1, 2).
3. ANALYSIS
3.1. A portion of the solder mass 0.5 g is placed in a low glass with a capacity of 50 cmand dissolved in 15 cm
of the mixture for dissolving at a moderate heat. After dissolution, the sample is added to a solution of 15 cm
of perchloric acid and evaporated until the appearance of dense white fumes. After cooling, add 5 cm
of the mixture for dissolution and again evaporated to fumes of perchloric acid. This operation is repeated two more times.
The contents of the beaker add 1 cmof concentrated nitric acid in two doses (0.5 cm
), gently warmed until the decomposition of lead bromide, removal of the bromine and the allocation of thick white vapour. If the solution is clear*, it is evaporated to a volume of about 2 cm
(level of the solution in a glass mark a pencil on glass), cooled, poured 20 cm
of water, transferred to a volumetric flask with a capacity of 100 cm
, is diluted with water to a volume of 50 cm
, neutralized with ammonia to pH 2−3 (universal indicator paper), then pour the 25 cm
of the reaction mixture was adjusted to the mark with water, mix. After 30 min measure optical density of solution on a photoelectrocolorimeter with a green light filter (wave-length 510 nm) in a cuvette with a layer thickness of 5 cm.
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* In that case, if the solution be turbid, add another 5 cmmixture for dissolving, evaporated to fumes of perchloric acid, destroying the lead bromide when heated with nitric acid.
A solution of comparison used water.
At the same time through the analysis of spend control experience. Mass fraction of iron is found by a calibration schedule, taking into account the correction for the reagents.
(Changed edition, Rev. N 1, 2).
3.2. In the analysis of solders containing cadmium, after the transfer of solution volumetric flask with a capacity of 100 cmand diluting with water to a volume of 50 cm
is neutralized with ammonia to pH 2−3 (universal indicator paper), poured thereto 10 cm
solution orthophenanthroline, 25 cm
of the reaction mixture and further analysis is carried out as specified in clause 3.1.
3.3. In the analysis of solders brand POS 61-M after evaporation of the hydrochloric acid to a volume of 2 cmand cooling it, the contents of the Cup diluted with water to a volume of 40 cm
. The solution is placed 5 g of granulated lead, close a glass watch glass and boil moderately for 15 minutes, adding water up to the mark as evaporation of the solution. Then add 1 g of lead and boil for 1 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.
The solution was transferred to volumetric flask with a capacity of 100 cm, 25 cm pour the
reaction mixture, adjusted to the mark with water, mixed and further analysis is carried out as specified in clause 3.1.
3.2, 3.3. (Changed edition, Rev. N 1).
3.4. Construction of calibration curve
In glasses with a capacity of 50 cmeach are placed 0; 0,5; 1,0; 2,0; 3,0; 5,0; 7,0; 9,0 and 11.0 cm
standard solution B, add 5 cm
of perchloric acid and evaporated to a volume of about 2 cm
(level of the solution in a glass mark a pencil on the glass). Cooled, transferred to a volumetric flask with a capacity of 100 cm
, is diluted with water to a volume of 50 cm
, neutralized with ammonia to pH 2−3 (universal indicator paper), add 25 cm
of the reaction mixture and further analysis is carried out as specified in clause 3.1.
On the found values of optical densities of solutions and their corresponding weight fractions of iron to build the calibration graph, taking into account the correction for the reagents.
(Changed edition, Rev. N 1, 2).
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of iron () in percent is calculated by the formula
where is the mass of iron 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 iron, % |
Allowable absolute differences, % |
| From 0.001 to 0.002 |
0,0005 |
| SV. Of 0.002 «to 0.005 |
0,001 |
| «0,005» 0,01 |
0,002 |
| «0,01» 0,02 |
0,004 |
(Changed edition, Rev. N 1, 2).
