GOST 1293.9-78
GOST 1293.9−78 lead-antimony Alloys. Method for the determination of magnesium (with Amendments No. 1, 2)
GOST 1293.9−78
Group B59
INTERSTATE STANDARD
LEAD-ANTIMONY ALLOYS
Method for determination of magnesium
Antimonous lead alloys.
Method for determination of magnesium
AXTU 1709
Date of introduction 1980−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
R. D. Kogan, A. M. Nushtaeva
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. INSTEAD 1293.9−67*
________________
*Probably a mistake of the original. Should read: GOST 1293.9−67. — Note the manufacturer’s database.
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
The designation of the reference document referenced |
Paragraph number section |
GOST 1293.6−78 |
1.1, 5.1 |
GOST 1770−74 |
2 |
GOST 4526−75 |
2 |
GOST 5817−77 |
2 |
GOST 6709−72 |
2 |
GOST 11125−84 |
2 |
GOST 14919−83 |
2 |
GOST 25336−82 |
2 |
5. Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
6. REPRINT (October 1999) with Amendments No. 1, 2 approved in December 1983, November 1987 (IUS 4−84, 2−88)
This standard establishes the atomic absorption method for determination of magnesium content (with mass fraction of magnesium from 0.001 to 0.04%) in the lead-antimony alloy.
The method is based on measuring absorption lines of magnesium RUB 285.2 nm with the introduction of the sample solution and solutions for constructing the calibration curve in the air-acetylene flame. Samples of lead-antimony alloy is pre-transferred to the solution by decomposition in a mixture of dilute nitric and tartaric acids.
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 1293.6.
(Changed edition, Rev. N 1).
2. APPARATUS, MATERIALS AND REAGENTS
Spectrophotometer atomic absorption of any brand.
Air, compressed under a pressure of 5.07·10-6,08·10PA (5−6 kgf/cm).
Acetylene in cylinders.
Electric resistance furnace.
Laboratory scales.
Desiccator, according to GOST 25336.
Electric tile according to GOST 14919, covered with a quartz plate.
Cookware PTFE or quartz (cups, glasses, lids, etc.).
Glasses glass.
Pipettes for NTD, with a capacity of 1, 2, 5 and 10 cm.
Volumetric flasks according to GOST 1770, with a capacity of 50, 100, 250 and 1000 cm.
Distilled water according to GOST 6709, double-distilled in quartz apparatus or purified on ion exchange column.
Nitric acid of high purity according to GOST 11125, mortar 1:3 and 1:6.
Tartaric acid according to GOST 5817, a solution of 2.7 M.
Magnesium oxide according to GOST 4526, grade not lower than C. D. and.
Standard solutions of magnesium.
Solution a containing 1 mg/cmmagnesium: magnesium oxide is calcined for 1 h in muffle at 600 °C and then placed in a desiccator. From the cooled powder of magnesium oxide take the hitch weight 1,6583 g, placed in a glass beaker, dissolved in 10 cmof nitric acid when heated, transferred to a volumetric flask with a capacity of 1000 cmand adjusted to the mark with distilled water.
Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, bring to volume with distilled water and mix. 1 cmof the solution contains 100 mg of magnesium.
Solution: 10 cmof a solution transferred to a volumetric flask with a capacity of 100 cm, bring to volume with distilled water and mix. 1 cmof solution contains 10 mg of magnesium.
Solution G: 10 cmsolution is transferred to a volumetric flask with a capacity of 100 cm, bring to volume with distilled water and mix. 1 cmsolution G contains 1 mg of magnesium.
Solutions for constructing the calibration curve containing 0,1; 0,2; 0,5; 1; 2; 5 and 10 µg/cmof magnesium, prepared from standard solutions B, C and d according to the table.
The magnesium content in the solution |
The number of standard solution, cm |
The volume of the solution | ||
B | In | G |
||
0,1 | - | - | 5 |
50 |
0,2 | - | - | 10 |
50 |
0,5 | - | 2,5 | - |
50 |
1 | - | 5,0 | - |
50 |
2 | 2 | - | - |
100 |
5 | 5 | - | - |
100 |
10 | 10 | - | - |
100 |
In the same flask with a capacity of 50 cm(100 cm) and add 5 cm(10 cm) of nitric acid solution 1:3, adjusted to the mark with distilled water, stirred and poured into a non-glass vessels (Teflon, quartz, etc.).
Sec. 2. (Changed edition, Rev. N 1, 2).
3. ANALYSIS
Test lead for analysis comes in the form of rods with diameter of 7−10 mm, length of 70−100 mm or shavings. In the first case the sample is cut with a box cutter. A piece of sample or a portion of chips (about 5 g) is weighed on an analytical balance and record the exact weight for further calculations. Then remove the contaminated surface by washing the samples for 30 s with nitric acid, diluted 1:3, for samples in the form of a piece and 1:6 for the sample chips.
The cleaning procedure of the sample is performed as follows: a sample placed in a quartz Cup, pour the acid solution so that it covers the sample. 30 with the acid solution is decanted and the sample washed with distilled water prominance, holding a Cup sloping. The sample is then transferred in a Teflon glass or leave in a quartz Cup, pour 12 cmof a solution of tartaric acid and 35 cmdiluted 1:3 of nitric acid, cover with lid and heated on a tile, covered with a quartz plate, until complete decomposition of the sample. The decomposed sample was transferred to volumetric flask with a capacity of 250 cmand poured in PTFE or quartz glassware. The decomposition of spend control experience. Samples and solutions for constructing the calibration curve is sprayed into the flame and measure the magnitude of the absorption line of magnesium on atomic absorption spectrophotometer. Use two ways to measure the magnitude of the absorption depending on the instrument model. The spectrophotometers of the firm «Perkin-Elmer» the measurement is performed in the «concentration» method of «three standards». On the scoreboard get the results in µg/cm. Spectrophotometers on the other models work in the mode «absorption» method «limiting solutions» with a record on the recorder. The method of «limiting solutions» is to obtain the counts for the sample solution and two solutions for constructing the calibration curve, one of which gives a higher and the other lower count compared to the reference sample solution.
Sec. 3. (Changed edition, Rev. N 1, 2).
4. PROCESSING OF THE RESULTS
4.1. If the measurement was taken on the recorder, then with a ruler measure the length of the peaks in millimeters and build a calibration curve in the coordinates: the concentration of magnesium in solution in µg/cmlength peaks in mm. When measuring the magnitude of the absorption lines of magnesium in the pointer-type device calibration curve constructed in the coordinates: the concentration of magnesium in solution in g/cm — readings of the gauge.
Mass fraction of magnesium (a) in percent is calculated by the formula
,*
where the amount of magnesium was found in the calibration schedule, µg/cm;
— the volume of the sample solution, cm;
— weight of sample, mg;
1000* — conversion factor from milligrams to micrograms.
_______________
* Formula and explication to it correspond to the original. — Note the CODE.
In the calculation it is necessary to consider the control sample when the content of magnesium in it is comparable to the content of magnesium in the sample.
The final result of the analysis be the arithmetic mean of two parallel definitions, the difference between which should not exceed , where is the arithmetic mean of parallel definitions.
(Changed edition, Rev. N 1)
.
4.2. (Deleted, Rev. N 1).
5. SAFETY REQUIREMENTS
5.1. Safety requirements — according to GOST 1293.6.
Sec. 5. (Added, Rev. N 1).