GOST 1219.8-74
GOST 1219.8−74 calcium Babbits. Method for the determination of copper content (with Amendments No. 1, 2)
GOST 1219.8−74
Group B59
INTERSTATE STANDARD
CALCIUM BABBITS
Method for the determination of copper content
Lead-calcium bearing alloys.
Method for determination of copper content
ISS 77.160.20*
AXTU 1709
____________________
* In the index «National standards» 2006
ISS
Date of introduction 1975−01−01
The decision of the State standards Committee of the Council of Ministers of the USSR from January 17, 1974 N 150 date of introduction is established 01.01.75
Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)
REPLACE GOST 1219−60 in part of sec. IX
EDITION (September 2003) with Changes No. 1, 2 approved in November 1979 and November 1984 (IUS 1−80, 2−85).
This standard applies to calcium babbits and sets photocolorimetric method for the determination of copper content (when the mass fraction of copper from 0.01 to 0.20%).
The method is based on reaction of interaction of copper with sodium diethyldithiocarbamate with the formation of complex compounds colored in yellow or yellowish-brown depending on the copper content.
In dilute solutions forms a colloidal solution which is the measurement of optical density is stabilized by adding a solution of gelatin as a protective colloid.
Influence of interfering components can be eliminated by deposition of sulfuric acid and an aqueous solution of ammonia.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 1219.0−74.
2. APPARATUS, REAGENTS AND SOLUTIONS
Photocolorimeter or spectrophotometer.
Nitric acid GOST 4461−77 diluted 1:1.
Sulfuric acid GOST 4204−77, diluted 2:98.
Iron chloride according to GOST 4147−74, 5% solution.
Ammonia water according to GOST 3760−79.
Gelatin food according to GOST 11293−89, a 0.5% solution.
Litmus indicator paper.
Diethyldithiocarbamate sodium GOST 8864−71, a 0.5% solution.
Copper electrolyte.
Solutions of copper.
Solution A, prepared as follows: 0.1 g of copper is dissolved in 10 cmof nitric acid, diluted 1:1. The solution was transferred to a volumetric flask with a capacity of 1 DM
, cooled, made up to the mark with water and mix.
1 cmof solution A contains 0.1 mg of copper.
Solution B is prepared as follows: 10 cmof solution A is placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
1 cmof a solution contains 0.01 mg of copper.
(Changed edition, Rev. N 1).
3. ANALYSIS
3.1. A portion of the babbit 1 g is placed in a conical flask with a capacity of 250 cm, dissolved in 20 cm
of nitric acid, diluted 1:1, and heated to complete dissolution of the alloy and removal of nitrogen oxides.
After cooling, poured 20 cmwater and 5 cm
of sulphuric acid, allow to settle 10 min, and then filtered off the precipitate of lead sulphate and washed it in the flask and on the filter 3−4 times with sulphuric acid, diluted 2:98. The precipitate is discarded. To the filtrate add 5 cm
of a solution of ferric chloride, neutralized with an aqueous solution of ammonia until the color of indicator paper litmus blue and pour another 2 cm
of ammonia in excess. The solution is heated to boiling and coagulation of the precipitate.
The precipitate was filtered off on a medium density filter and washed 3−4 times with cold water. The filtrate and the washings collected in a volumetric flask with a capacity of 250 cm, was adjusted to the mark with water and mix.
Aliquot part of the solution was 50 cmfor the mass concentration of copper up to 0.1% and 10 cm
for the mass concentration of copper in excess of 0.1% (in the final volume of the mass fraction of copper should not exceed 0.1 mg) was placed in a volumetric flask with a capacity of 100 cm
, add 5 cm
of the gelatin solution, 10 cm
of ammonia solution, 10 cm
of a solution of sodium diethyldithiocarbamate, adjusted to the mark with water and mix.
Optical density of the solution immediately measured on photocolorimeter with a blue light filter (light transmission region 410−420 nm) in a cuvette with a layer thickness of 30 mm. with a Solution of comparison is aliquota part of the study solution to which is added all the reagents necessary to photocolorimetry, with the exception of the solution of sodium diethyldithiocarbamate. At the same time through all stages of the analysis carried out control experience in the determination of the copper content in the reagents.
On the found values of optical density of the analyzed solution with the adjusted control experience find the copper content in the calibration g
Rafik.
3.2. Construction of calibration curve.
In a volumetric flask with a capacity of 100 cmplaced 0; 1,0; 3,0; 5,0; 7,0; 10,0 cm
of solution B, which corresponds to 0; 0,01; 0,03; 0,05; 0,07; 0,10 mg of copper. Then add everything you need to photocolorimetry reagents in the same sequence and in the same amounts as specified in clause 3.1.
A solution of comparison used aliquot part of the solution B with the addition of all reagents except the solution of sodium diethyldithiocarbamate.
On the found values of optical density and corresponding concentration values of a standard solution of copper build a calibration curve.
4. PROCESSING OF THE RESULTS OF THE ANALYSIS
4.1. Mass fraction of copper () in percent is calculated by the formula
where the amount of copper found in the calibration graphics mg;
— linkage, the corresponding aliquote part of the solution, g;
— a conversion factor of milligrams to grams.
4.2. Allowable absolute differences between the extreme results of the analysis should not exceed 0,002% when the mass fraction of copper from 0.01 to 0.03%; 0,004% when the mass fraction of copper in excess of 0.03 to 0.1%; 0,005% when the mass fraction of copper, more than 0.1 to 0.2%.
(Changed edition, Rev. N 1, 2).
